BCLA CLEAR – Medical use of contact lenses

      Abstract

      The medical use of contact lenses is a solution for many complex ocular conditions, including high refractive error, irregular astigmatism, primary and secondary corneal ectasia, disfiguring disease, and ocular surface disease. The development of highly oxygen permeable soft and rigid materials has extended the suitability of contact lenses for such applications. There is consistent evidence that bandage soft contact lenses, particularly silicone hydrogel lenses, improve epithelial healing and reduce pain in persistent epithelial defects, after trauma or surgery, and in corneal dystrophies. Drug delivery applications of contact lens hold promise for improving topical therapy. Modern scleral lens practice has achieved great success for both visual rehabilitation and therapeutic applications, including those requiring retention of a tear reservoir or protection from an adverse environment. This report offers a practical and relevant summary of the current evidence for the medical use of contact lenses for all eye care professionals including optometrists, ophthalmologists, opticians, and orthoptists. Topics covered include indications for use in both acute and chronic conditions, lens selection, patient selection, wear and care regimens, and recommended aftercare schedules. Prevention, presentation, and management of complications of medical use are reviewed.

      Keywords

      Abbreviations

      BCVA
      best-corrected visual acuity
      BSCL
      bandage soft contact lens
      cGVHD
      chronic graft-versus-host disease
      CXL
      Corneal Collagen Cross-linking
      EDTA
      ethylenediamine-tetraacetic acid
      FDA
      Food and Drug Administration (US)
      IATS
      Infant Aphakia Treatment Study
      IOP
      intraocular pressure
      ICRS
      Intracorneal Ring Segments
      LASEK
      Laser Epithelial Keratomileusis
      LASIK
      laser-assisted in situ keratomileusis
      LSCD
      limbal stem cell deficiency
      MK
      microbial keratitis
      NEI-VFQ-25
      National Eye Institute Visual Function Questionnaire (25 item)
      NSAID
      nonsteroidal anti-inflammatory drug
      OSDI
      ocular surface disease index
      PED
      persistent epithelial defect
      PK
      penetrating keratoplasty
      PMD
      pellucid marginal degeneration
      PMMA
      polymethyl methacrylate
      PRK
      photorefractive keratectomy
      PROSE
      Prosthetic Replacement of the Ocular Surface Ecosystem
      QOL
      quality of Life
      RCES
      Recurrent Corneal Erosion Syndrome
      SiHy
      silicone hydrogel
      SLK
      superior limbic keratoconjunctivitis
      SJS
      Stevens-Johnson syndrome
      TFOS DEWS II
      Tear Film and Ocular Surface Dry Eye Workshop II

      1. Introduction

      Clinicians have long appreciated that contact lenses play a role in the care of patients with ophthalmic disease. Contact lenses therefore have a medical use, in addition to their use for correction of refractive error. This medical use has evolved over decades alongside advances in contact lens materials and design. Appreciation of the role a lens might play in stabilising the ocular surface, neutralising refractive error, and improving visual function, combined with awareness of potential complications and how to avoid them, has yielded vast experience and a body of literature on the medical use of contact lenses.
      Statements on the quality of evidence are based on the approach discussed in the CLEAR Evidence-based Practice Report [
      • Wolffsohn J.S.
      • Dumbleton K.
      • Huntjens B.
      • Kandel H.
      • Koh S.
      • Kunnen C.M.E.
      • et al.
      CLEAR - evidence based contact lens practice.
      ].

      1.1 Definition of medical contact lenses

      The literature search conducted to create this report failed to find a field-wide, accepted definition for medical contact lenses. After discussion and consensus, the following definition for medical contact lenses has been adopted by the subcommittee on Medical Use Contact Lenses:
      Medical Contact Lenses are any type of contact lens that is worn for the primary purpose of treating an underlying disease state or complicated refractive status. Medical contact lenses may or may not correct refractive error. Medical contact lenses are prescribed for reasons other than the cosmetic purpose of eliminating the need for spectacles. There is no universally accepted definition for medical contact lenses, but in some countries, some insurance companies set requirements as to the condition or diagnosis (e.g., cornea ectasia, unilateral aphakia) or degree of refractive error (e.g. high myopia) before a coverage or reimbursement is granted. Because of this, requirements and definitions can vary from nation to nation based on the structure of healthcare in the respective country.

      1.1.1 Regulatory bodies, labelling, and “therapeutic” lenses

      In the United States (US), mass produced contact lenses are regulated by the US Food and Drug Administration (FDA). The first (hydrogel) soft CL was approved by the US FDA in 1971 as a new drug [
      • Hampton D.
      • Tarver M.E.
      • Eydelman M.B.
      Latest food and drug administration’s efforts to improve safe contact lens use.
      ,
      • Saviola J.F.
      Contact lens safety and the FDA: 1976 to the present.
      ]. Contact lenses were later reclassified by the US FDA as Class III medical devices (high risk) in 1976 when the Medical Device Amendment was passed. Later regulatory revisions have since reclassified daily wear soft lenses and rigid corneal lenses as Class II medical devices (moderate to high risk), while overnight and myopia management contact lenses, are considered Class III medical devices [
      • Zaki M.
      • Pardo J.
      • Carracedo G.
      A review of international medical device regulations: contact lenses and lens care solutions.
      ]. The European Medicines Agency of the European Union, the Australian Therapeutic Goods Administration in Australia, the Drug Controller General of India, and the National Medical Products Administration in China perform a similar function and have similar classification systems for regulating medical devices [
      • Zaki M.
      • Pardo J.
      • Carracedo G.
      A review of international medical device regulations: contact lenses and lens care solutions.
      ].
      National regulatory bodies take guidance from the International Organisation for Standardization when creating their policies. This body has specifically set international industry standards that are broadly recognised by regulatory agencies throughout the world for lens and care product labelling [
      • Hampton D.
      • Tarver M.E.
      • Eydelman M.B.
      Latest food and drug administration’s efforts to improve safe contact lens use.
      ]. They have also set efficacy standards for the care systems needed to maintain contact lenses [
      • Kramer A.
      • Rudolph P.
      • Werner H.P.
      Antimicrobial efficacy of contact lens care products and critical comment on ISO/FDIS 14729.
      ]. Professional organisations likewise provide best practice guidance to clinicians, and they provide feedback to the above regulatory bodies when new policies are being set [
      • Steinemann T.L.
      Microbiological testing for contact lens care products-public workshop: FDA white oak conference center, Silver Spring Maryland.
      ].
      While any CL might be used medically or as a therapeutic or bandage CL, some contact lenses are labelled for use as a bandage lens or with a therapeutic indication for use.

      1.1.2 Clinical definitions

      Contact lenses are used for numerous medical purposes that include, but are not limited to, treating patients with corneal ectasia, ocular surface disease, after ocular surgery and in the setting of high refractive error [
      • Nau C.B.
      • Harthan J.
      • Shorter E.
      • Barr J.
      • Nau A.
      • Chimato N.T.
      • et al.
      Demographic characteristics and prescribing patterns of scleral lens fitters: the SCOPE study.
      ]. The authors recommend the following set of definitions to be adopted by the community for medical use of contact lenses.
      • Therapeutic or Bandage Contact Lenses are lenses that are used for the treatment of ocular discomfort or to support the cornea during healing after surgery or when the cornea is being treated for an underlying disease state or to protect the cornea from the environment or mechanical interaction with the lids.
      • Rehabilitative Contact Lenses are lenses that are prescribed for conditions that prevent a patient from achieving adequate visual function with spectacles because of high, irregular, or asymmetric refractive error. Partially or completely occlusive lenses that improve function or cosmesis after trauma, surgery, or stroke also fall into this category.

      1.2 Lens types used for medical purposes

      It is widely accepted that Müller described the first CL for correcting refractive error in the late 1880s [
      • Pearson R.M.
      • Efron N.
      Hundredth anniversary of August Müller’s inaugural dissertation on contact lenses.
      ], but concurrently, in 1888, Fick described what may be the first medical use of contact lenses in his report of the improvement of vision in patients with keratoconus [
      • Fick A.E.
      A contact-lens. 1888 (translation).
      ]. Müller’s lenses, which were scleral lenses made of glass and used to correct his own high myopia, unfortunately induced corneal oedema and ocular pain because they were impermeable to oxygen. Because of this, they could only be worn for short periods of time. Polymethyl methacrylate (PMMA) corneal lenses were used on a therapeutic basis as early as the late 1950s and early 1960s [
      • Ridley F.
      Contact lenses in treatment of keratoconus.
      ,
      • Ridley F.
      Therapeutic uses of scleral contact lenses.
      ]. Oxygen impermeable PMMA contact lenses have largely been replaced by rigid lens materials, which are used on a therapeutic basis in corneal and scleral lenses [
      • Cotter J.M.
      • Rosenthal P.
      Scleral contact lenses.
      ,
      • Foss A.J.E.
      • Trodd T.C.
      • Dart J.K.G.
      Current indications for scleral contact lenses.
      ,
      • Rosenthal P.
      • Croteau A.
      Fluid-ventilated, gas-permeable scleral contact lens is an effective option for managing severe ocular surface disease and many corneal disorders that would otherwise require penetrating keratoplasty.
      ,
      • Schein O.
      • Rosenthal P.
      • Ducharme C.
      A gas-permeable scleral contact lens for visual rehabilitation.
      ].
      The soft contact lens market emerged in the early 1970s with the creation of cross-linked hydrogel polymers and the introduction of hydrogel contact lenses [
      • Buxton J.N.
      • Locke C.R.
      A therapeutic evaluation of hydrophilic contact lenses.
      ,
      • Gasset A.R.
      • Kaufman H.E.
      Therapeutic uses of hydrophilic contact lenses.
      ,
      • Kaufman H.
      • Uotila M.
      • Gasset A.
      • Wood T.
      • Ellison E.
      The medical uses of soft contact lenses.
      ,
      • Amos D.M.
      The use of soft bandage lenses in corneal disease.
      ,
      • Dohlman C.
      • Boruchoff S.A.
      • Mobilia E.F.
      Complications in use of soft contact lenses in corneal disease.
      ,
      • Lindahl K.J.
      • DePaolis M.D.
      • Aquavella J.V.
      • Temnycky G.O.
      • Erdey R.A.
      Applications of hydrophilic disposable contact lenses as therapeutic bandages.
      ,
      • Mobila E.
      • Dohlman C.
      • Holly F.
      A comparison of various soft contact lenses for therapeutic purposes.
      ]. Hydrogel contact lenses inherently lacked the ability to transmit enough oxygen to the cornea in order to avoid corneal hypoxia during overnight wear [
      • Buxton J.N.
      • Locke C.R.
      A therapeutic evaluation of hydrophilic contact lenses.
      ], which propelled the creation of the much more oxygen permeable silicone and then silicone hydrogel (SiHy) contact lenses [
      • Nilsson S.E.G.
      Seven-day extended wear and 30-day continuous wear of high oxygen transmissibility soft silicone hydrogel contact lenses: a randomized 1-year study of 504 patients.
      ,
      • Schafer J.
      • Mitchell G.L.
      • Chalmers R.L.
      • Long B.
      • Dillehay S.
      • Barr J.
      • et al.
      The stability of dryness symptoms after refitting with silicone hydrogel contact lenses over 3 years.
      ,
      • Musgrave C.S.A.
      • Fang F.
      Contact lens materials: a materials science perspective.
      ]. There was hope that SiHy contact lenses would reduce the rate of microbial keratitis (MK) associated with overnight night CL wear. Post-market experience reveals that infection rates are similar between SiHy and hydrogel contact lenses [
      • Stapleton F.
      • Keay L.
      • Edwards K.
      • Holden B.
      The epidemiology of microbial keratitis with silicone hydrogel contact lenses.
      ,
      • Holden B.A.
      • Sweeney D.F.
      • Sankaridurg P.R.
      • Carnt N.
      • Edwards K.
      • Stretton S.
      • et al.
      Microbial keratitis and vision loss with contact lenses.
      ], While hydrogel contact lenses are still labelled and used in some countries for overnight wear and as therapeutic or bandage lenses, it is generally only SiHy lenses that currently carry therapeutic or bandage indications for use. The following is a discussion on how these material properties, modes of wear, and innovation in design might affect the choice of lens for medical use of contact lenses.

      1.2.1 Hydrogel/silicone hydrogel

      The first US FDA approved soft contact lens was a conventional hydrogel lens (Soflens) developed by Bausch and Lomb [
      • Buxton J.N.
      • Locke C.R.
      A therapeutic evaluation of hydrophilic contact lenses.
      ]. Conventional hydrogel contact lenses fail to meet the criteria (87.0 Dk/t) set forth by Holden and Mertz to provide the cornea with enough oxygen to avoid excess corneal swelling during overnight wear [
      • Holden B.A.
      • Mertz G.W.
      Critical oxygen levels to avoid corneal edema for daily and extended wear contact lenses.
      ,
      • Sweeney D.F.
      Corneal exhaustion syndrome with long-term wear of contact lenses.
      ], a limitation to their use (see CLEAR Complications Report [
      • Stapleton F.
      • Bakkar M.
      • Carnt N.
      • Chalmers R.
      • Kumar A.
      • Marasini S.
      • et al.
      CLEAR: contact lens complications.
      ]). Eventually, this challenge of hypoxia was circumvented by the release of the first silicone hydrogel contact lens (PureVision) by Bausch & Lomb with reports of improved performance compared to hydrogel lenses for both cosmetic [
      • Nilsson S.E.G.
      Seven-day extended wear and 30-day continuous wear of high oxygen transmissibility soft silicone hydrogel contact lenses: a randomized 1-year study of 504 patients.
      ] and broad therapeutic use [
      • Lim L.
      • Tan D.
      • Chan W.
      Therapeutic use of Bausch & Lomb PureVision contact lenses.
      ]. While silicone hydrogel contact lenses have a reduced likelihood of corneal hypoxia [
      • Dumbleton K.
      Noninflammatory silicone hydrogel contact lens complications.
      ,
      • Brennan N.A.
      • Coles M.L.C.
      • Comstock T.L.
      • Levy B.
      A 1-year prospective clinical trial of balafilcon A (PureVision) silicone-hydrogel contact lenses used on a 30-day continuous wear schedule.
      ,
      • Chalmers R.L.
      • Dillehay S.
      • Long B.
      • Barr J.T.
      • Bergenske P.
      • Donshik P.
      • et al.
      Impact of previous extended and daily wear schedules on signs and symptoms with high Dk lotrafilcon A lenses.
      ,
      • Sweeney D.F.
      Have silicone hydrogel lenses eliminated hypoxia?.
      ], they have failed to address many of the other issues that are problematic for CL wearers [
      • Stapleton F.
      • Tan J.
      Impact of contact lens material, design, and fitting on discomfort.
      ].
      Furthermore, the literature currently lacks well-controlled studies related to these materials being used specifically for medical purposes. One of the first reports on therapeutic soft was published in 1971 [
      • Buxton J.N.
      • Locke C.R.
      A therapeutic evaluation of hydrophilic contact lenses.
      ]. That study described the use of the Soflens for treating 45 patients with corneal disease (corneal oedema, dry eyes, corneal ulcers, and advanced corneal conditions such as keratoconus). They found hydrogel contact lenses were an effective bandage lens for reducing external ocular discomfort. Early evidence in a study with 278 participants demonstrated that hydrogel contact lenses were effective therapeutic lenses for treating about half of participants with acute or chronic corneal diseases [
      • Dohlman C.
      • Boruchoff S.A.
      • Mobilia E.F.
      Complications in use of soft contact lenses in corneal disease.
      ]. In a prospective study, 91 % of the adult participants (n = 70) found benefit from wearing silicone hydrogel contact lenses for therapeutic purposes for conditions such as bullous keratopathy and post-operative corneal epitheliopathy [
      • Ambroziak A.M.
      • Szaflik J.P.
      • Szaflik J.P.
      Therapeutic use of a silicone hydrogel contact lens in selected clinical cases.
      ]. Similarly, silicone hydrogel contact lenses can be beneficial post-LASEK [
      • Szaflik J.P.
      • Ambroziak A.M.
      • Szaflik J.P.
      Therapeutic use of a lotrafilcon A silicone hydrogel soft contact lens as a bandage after LASEK surgery.
      ], and a prospective study found that SiHy lenses (n = 29) are safe and effective for children for therapeutic purposes for conditions such as corneal burns or wounds [
      • Bendoriene J.
      • Vogt U.
      Therapeutic use of silicone hydrogel contact lenses in children.
      ]. Similarly, a multicentre study reported general success of a senofilcon A lens as bandage lens for a range of therapeutic indications [
      • Shafran T.
      • Gleason W.
      • Osborn Lorenz K.
      • Szczotka-Flynn L.B.
      Application of senofilcon A contact lenses for therapeutic bandage lens indications.
      ]. These data fail to provide clear evidence with regards to selecting a hydrogel or silicone hydrogel contact lens for medical use. Similarly, disposable soft contact lens that are replaced on a daily, bi-weekly, or monthly basis are now readily available, though there is no clear evidence for selecting one wear schedule over another for medical purposes [
      • Sankaridurg P.
      • Lazon De La Jara P.
      • Holden B.
      The future of silicone hydrogels.
      ].

      1.2.2 Specialty soft lenses

      Standard, commercially available soft contact lenses are typically between 13.8 mm and 14.5 mm in diameter. There are two special types of soft lenses that have medical use: large diameter hydrogel soft lenses and custom toric hydrogel or SiHy lenses.
      Large diameter hydrogel soft contact lenses are available for off the shelf use in eyes with larger corneal diameters and can be used for medical purposes such as bleb leak or when there is poor retention of typical diameter lenses due to exposure, ocular surface disease or unusual corneal or scleral topography. The sub-committee on Medical Use Contact Lenses acknowledges that there are off the shelf large diameter contact lenses (e.g., Kontur, Hydrolens, Eye-58) and that these are in widespread use in the locales in which they are marketed. However, no primary references related to these contact lenses were identified during the preparation of this report, and because of this, more investigation on this topic is needed. A randomised, crossover study with 25 patients who wore a well-fitted optimum diameter soft contact lenses or a soft lens that was 1.2 mm larger in successive trials were examined to determine if excessively large lens would have a negative impact on the ocular surface [
      • Wolffsohn J.
      • Hall L.
      • Young G.
      Clinical comparison of optimum and large diameter soft contact lenses.
      ]. While the larger lens did not fit as well, there was no difference in ocular comfort between the groups and there was minimal difference in ocular signs. This work will help to inform futures studies as to which parameters of custom soft contact lens fit are critical for success in diseased eyes.
      Current literature suggests good long-term tolerance of custom soft contact lenses. A review of 11 charts from patients who began wearing their custom soft contact lenses between 1982 and 1984 found that 7 out of these 11 patients were still wearing their lenses in 1986 [
      • Molinari J.F.
      • Ebert C.A.
      • Caplan L.
      Clinical evaluation of a custom toric hydrogel contact lens.
      ]. A study that enrolled 105 patients who had astigmatism and who were empirically fitted with the Igel Rx toric soft lens, found that 74 % of the enrolled subjects were able to wear the contact lens full-time and that 89 % of enrolled subjects were able to achieve vision that was within one line of their best-corrected visual acuity [
      • De Brabander J.
      • Brinkman C.J.J.
      • Nuyts R.M.M.A.
      • Van Mil C.
      • Sax T.
      • Brookman E.
      Clinical evaluation of a custom-made toric soft lens.
      ]. A more recent 12-month prospective study with the Kerasoft® iC (custom soft) contact lens in a group of 43 patients who had a variety of irregular corneal conditions found that, at 12 months, 84 % of the subjects were still wearing these lenses with the majority achieving good vision and comfort [
      • Su S.
      • Johns L.
      • Rah M.J.
      • Ryan R.
      • Barr J.
      Clinical performance of KeraSoft(®) IC in irregular corneas.
      ].

      1.2.3 Rigid corneal lenses

      While rigid corneal lenses make poor choices as therapeutic contact lenses for ocular surface disease because of their mobility, small diameter and associated tear film instability, rigid corneal lenses have been used for decades for visual rehabilitation [
      • Musgrave C.S.A.
      • Fang F.
      Contact lens materials: a materials science perspective.
      ,
      • Blackmore S.J.
      The use of contact lenses in the treatment of persistent epithelial defects.
      ,
      • Mannis M.J.
      • Zadnik K.
      Fitting gas-permeable contact lenses after penetrating keratoplasty.
      ,
      • Espy J.W.
      An extended wear hard contact lens in aphakia.
      ]. Rigid corneal lenses may be particularly useful in patients with high refractive error or aphakia because the lenses needed to correct these conditions would be thick to meet power requirements, limiting oxygen transmission through the lens [
      • Espy J.W.
      An extended wear hard contact lens in aphakia.
      ]. Rigid corneal lenses allow for greater access to atmospheric oxygen than any soft lens which covers the cornea beyond the limbus. Additionally, rigid corneal lenses allow for much greater tear exchange compared to scleral lenses, especially a sealed one, so atmospheric oxygen should be more available to the cornea with this approach [
      • Michaud L.
      • van der Worp E.
      • Brazeau D.
      • Warde R.
      • Giasson C.J.
      Predicting estimates of oxygen transmissibility for scleral lenses.
      ,
      • Skidmore K.V.
      • Walker M.K.
      • Marsack J.D.
      • Bergmanson J.P.G.
      • Miller W.L.
      A measure of tear inflow in habitual scleral lens wearers with and without midday fogging.
      ], just as a SiHy lens is likely to allow for better tear exchange than a sealed scleral lens [
      • Paugh J.R.
      • Chen E.
      • Heinrich C.
      • Miller H.
      • Gates T.
      • Nguyen A.L.
      • et al.
      Silicone hydrogel and rigid gas-permeable scleral lens tear exchange.
      ]. Rigid corneal lenses are useful in the visual rehabilitation of corneal scars because their capacity to neutralise any corneal irregularity outweighs any worsening of straylight [
      • de Jong B.
      • van der Meulen I.J.E.
      • van Vliet J.M.J.
      • Lapid-Gortzak R.
      • Nieuwendaal C.P.
      • van den Berg T.J.T.P.
      Effects of corneal scars and their treatment with rigid contact lenses on quality of vision.
      ]. Nevertheless, the prescribing of rigid corneal lenses has lost some favour for cosmetic purposes and for corneal disease cases in recent years because of the challenges associated with fitting this modality and because many patients find scleral lenses more comfortable [
      • Efron N.
      Obituary—rigid contact lenses.
      ]. Some wearers of rigid corneal lenses however, report corneal lenses to be more comfortable than scleral lenses and chose to continue with them, suggesting that this modality remains an option for management of disease [
      • Levit A.
      • Benwell M.
      • Evans B.J.W.
      Randomised controlled trial of corneal vs. Scleral rigid gas permeable contact lenses for keratoconus and other ectatic corneal disorders.
      ].

      1.2.4 Hybrid lenses

      A hybrid lens is a contact lens that has a central rigid corneal lens for providing clear vision which is fused to a soft contact lens skirt intended to help with lens stability and comfort. The utility of early hybrid lenses was limited due to low oxygen transmission contributing to corneal neovascularisation and breakage at the lens skirt junction [
      • Abdalla Y.F.
      • Elsahn A.F.
      • Hammersmith K.M.
      • Cohen E.J.
      Synergeyes lenses for keratoconus.
      ]. Recently, a number of low quality evidence reports, which are fully described in sections 4.1.1 (keratoconus) and 4.2.1 (penetrating keratoplasty), suggest that hybrid lenses are useful in treating patients with irregular corneas (e.g. keratoconus) and with history of surgical interventions (e.g., keratoplasty) [
      • Nau A.C.
      A comparison of synergeyes versus traditional rigid gas permeable lens designs for patients with irregular corneas.
      ,
      • Hashemi H.
      • Shaygan N.
      • Asgari S.
      • Rezvan F.
      • Asgari S.
      ClearKone-synergeyes or rigid gas-permeable contact lens in keratoconic patients: a clinical decision.
      ,
      • Hassani M.
      • Jafarzadehpur E.
      • Mirzajani A.
      • Yekta A.
      • Khabazkhoob M.
      A comparison of the visual acuity outcome between Clearkone and RGP lenses.
      ,
      • Carracedo G.
      • González-Méijome J.M.
      • Lopes-Ferreira D.
      • Carballo J.
      • Batres L.
      Clinical performance of a new hybrid contact lens for keratoconus.
      ,
      • Altay Y.
      • Balta O.
      • Burcu A.
      • Ornek F.
      Hybrid contact lenses for visual management of patients after keratoplasty.
      ].

      1.2.5 Piggyback lenses

      A piggyback lens system, which is a rigid lens worn on top of a soft lens can be used for medical purposes when surgery, trauma, or disease results in irregular astigmatism or high power requirements, such that a rigid corneal lens is not tolerated [
      • Kok J.H.
      • van Mil C.
      Piggyback lenses in keratoconus.
      ]. Because of the combined thickness of two lenses on the eye, the issue of adequate oxygen transmission is critical to consider in selection of each lens [
      • Weissman B.A.
      • Ye P.
      Calculated tear oxygen tension under contact lenses offering resistance in series: piggyback and scleral lenses.
      ]. Many parameters can be manipulated along with adoption of innovations in lenses and materials, to improve comfort, vision, and physiological function [
      • Giasson C.J.
      • Perreault N.
      • Brazeau D.
      Oxygen tension beneath piggyback contact lenses and clinical outcomes of users.
      ,
      • López-Alemany A.
      • González-Méijome J.M.
      • Almeida J.B.
      • Parafita M.A.
      • Refojo M.F.
      Oxygen transmissibility of piggyback systems with conventional soft and silicone hydrogel contact lenses.
      ,
      • Florkey L.N.
      • Fink B.A.
      • Mitchell G.L.
      • Hill R.M.
      Corneal oxygen uptake associated with piggyback contact lens systems.
      ].

      1.2.6 Scleral lenses

      Scleral lenses were not only the first contact lens, but they were also the first contact lenses used for therapeutic purposes [
      • Ridley F.
      Therapeutic uses of scleral contact lenses.
      ,
      • van der Worp E.
      • Barnett M.
      • Johns L.
      Scleral lenses: history & future.
      ,
      • Gould H.L.
      Therapeutic effect of flush fitting scleral lenses and hydrogel bandage lenses.
      ]. Scleral lenses are large diameter contact lenses, initially impression moulded [
      • Ezekiel D.
      Gas permeable haptic lenses.
      ,
      • Lyons C.J.
      • Buckley R.J.
      • Pullum K.
      • Sapp N.
      Development of the gas-permeable impression-moulded scleral contact lens. A preliminary report.
      ] and then lathed, that completely vault the cornea and land on the sclera/episclera and overlying conjunctiva [
      • Schein O.
      • Rosenthal P.
      • Ducharme C.
      A gas-permeable scleral contact lens for visual rehabilitation.
      ,
      • Visser R.
      An innovative therapeutic scleral lens for various pathologies [in Dutch].
      ]. Scleral lenses enclose a fluid reservoir that is filled with preservative free sterile saline, creating a tear lens between the ocular surface and the contact lens. This feature neutralises the majority of anterior corneal aberrations, provides lubrication and support of the ocular surface, as well as protection from exposure and/or external mechanical irritation from the lids/lashes. Scleral lenses can play a therapeutic role in ocular surface disease and in the visual rehabilitation of corneal ectasia and irregular astigmatism [
      • Jacobs D.S.
      Update on scleral lenses.
      ] (see CLEAR Sclerals report [
      • Barnett M.
      • Courey C.
      • Fadel D.
      • Lee K.
      • Michaud L.
      • Montani G.
      • et al.
      CLEAR: scleral lenses.
      ]).
      Scleral lenses have important medical uses as bandage lenses for comfort, as therapeutic lenses for supporting the surface, and in improvement in vision in the setting of disease. There is a large body of evidence on the use of scleral lenses for visual rehabilitation in conditions characterised by irregular astigmatism, to be reviewed in section 4 below. Over 20 years ago, there emerged low quality evidence studies that supported prescribing scleral lenses as therapeutic contact lenses for patients who have severe dry eye. A study of 11 subjects found that 91 % had better visual acuity and symptomatic improvement while wearing modern scleral lenses [
      • Kok J.H.C.
      • Visser R.
      Treatment of ocular surface disorders and dry eyes with high gas-permeable scleral lenses.
      ]. A retrospective chart review including 49 patients who were fitted with scleral lenses for ocular surface diseases, such as Stevens-Johnson syndrome, with dry eye symptoms [
      • Romero-Rangel T.
      • Stavrou P.
      • Cotter J.
      • Rosenthal P.
      • Baltatzis S.
      • Foster C.S.
      Gas permeable scleral contact lens therapy in ocular surface disease.
      ], found that fitting these patients with scleral lenses resulted in 82 % having substantial improvements in ocular surface symptoms and 92 % having improvements in visual function and quality of life. Another retrospective chart review evaluated 48 patients who were fitted with scleral lenses after failure with other modalities [
      • Segal O.
      • Barkana Y.
      • Hourovitz D.
      • Behrman S.
      • Kamun Y.
      • Avni I.
      • et al.
      Scleral contact lenses may help where other modalities fail.
      ]. The authors found that, while not all patients could wear scleral lenses (10.4 %) due to mostly handling issues, 81 % of their included subjects had improvements in ocular surface symptoms, similar to the findings of Romero-Rangel et al. Similarly, Jacobs and Rosenthal performed a chart review of 33 patients fitted with scleral lenses for ocular surface disease who were subsequently contacted to complete a survey related to ocular surface symptoms. They found that 97 %, 94 %, and 97 % of their subjects had improvements in pain, photophobia, and quality of life, respectively [
      • Jacobs D.S.
      • Rosenthal P.
      Boston scleral lens prosthetic device for treatment of severe dry eye in chronic graft-versus-host disease.
      ]. The same group reported significant improvement in visual function as measured by NEI VFQ-25 in a 2006 cohort of 100 patients with ectasia, irregular astigmatism, and ocular surface disease [
      • Stason W.B.
      • Razavi M.
      • Jacobs D.S.
      • Shepard D.S.
      • Suaya J.A.
      • Johns L.
      • et al.
      Clinical benefits of the boston ocular surface prosthesis.
      ]. Consistent with these reports of broad utility, a survey of 292 practitioners revealed that scleral lens wear improves vision and reduces corneal staining in their patients [
      • Schornack M.
      • Nau C.
      • Nau A.
      • Harthan J.
      • Fogt J.
      • Shorter E.
      Visual and physiological outcomes of scleral lens wear.
      ]. In a study of corneal nerve structure and function in 20 patients fitted with a fluid filled scleral lens, patients with a distorted cornea had significantly reduced basal tear production and increased corneal sensation after long-term wear of the scleral lens, whereas patients with ocular surface disease did not show any changes in tear production or corneal sensation [
      • Wang Y.
      • Kornberg D.L.
      • St Clair R.M.
      • Lee M.
      • Muhic I.
      • Ciralsky J.B.
      • et al.
      Corneal nerve structure and function after long-term wear of fluid-filled scleral lens.
      ].

      2. Bandage lenses in the acute setting

      2.1 After keratorefractive procedures

      Bandage soft contact lenses (BSCLs) were incorporated into the post-operative regimen following surface ablation procedures to attenuate post-operative pain, reduce the need for topical and/or systemic analgesia, to provide the regenerating epithelium protection from shear stress induced by blinking, and promote re-epithelialisation. SiHy lens resulted in faster corneal reepithelialisation and reduced patient discomfort in comparison to a hydrogel lens [
      • Engle A.T.
      • Laurent J.M.
      • Schallhorn S.C.
      • Toman S.D.
      • Newacheck J.S.
      • Tanzer D.J.
      • et al.
      Masked comparison of silicone hydrogel lotrafilcon A and etafilcon A extended-wear bandage contact lenses after photorefractive keratectomy.
      ]. As discussed in the subsequent section, lens fitting has also been suggested to be important for achieving optimal pain control and epithelial healing [
      • Fay J.
      • Juthani V.
      Current trends in pain management after photorefractive and phototherapeutic keratectomy.
      ]. Drawbacks to the use of BSCLs in the acute setting are the same as for other CL uses, specifically the potential for infection. In a retrospective study across six military centres for kerato-refractive surgery, 25,337 eyes that underwent photorefractive keratectomy (PRK)were identified [
      • Wroblewski K.
      • Pasternak J.
      • Bower K.
      • Schallhorn S.
      • Hubickey W.
      • Harrison C.
      • et al.
      Infectious keratitis after photorefractive keratectomy in the united states army and navy.
      ], in which BSCL is standard part of post-operative regimen. Only five eyes in that cohort developed MK, four of which were culture positive for Staphylococcus, a common inhabitant of the normal skin microbiota.

      2.1.1 Photorefractive keratectomy (PRK)

      Numerous prospective studies provide strong evidence to support the use of BSCLs immediately following PRK. PRK is a procedure in which the corneal epithelium is removed, followed by ablation of the anterior limiting membrane and the stroma using the excimer laser, to alter corneal shape and thus refractive power. In almost all studies, ocular discomfort is assessed using validated subjective questionnaires. To mitigate pain and promote re-epithelialisation, BSCLs are usually worn for three to five days [
      • Edwards J.
      • Bower K.
      • Sediq D.
      • Burka J.
      • Stutzman R.
      • Vanroekel C.
      • et al.
      Effects of lotrafilcon a and omafilcon a bandage contact lenses on visual outcomes after photorefractive keratectomy.
      ,
      • Razmjoo H.
      • Abdi E.
      • Atashkadi S.
      • Reza A.
      • Reza P.
      • Akbari M.
      Comparative study of two silicone hydrogel contact lenses used as bandage contact lenses after photorefractive keratectomy - PubMed.
      ]. Reports of the additive use of BSCLs along with topical anaesthetic agents, topical nonsteroidal anti-inflammatory (NSAID) eye drops, or both, after PRK [
      • Cherry P.
      • Tutton M.
      • Adhikary H.
      • Banerjee D.
      • Garston B.
      • Hayward J.
      • et al.
      The treatment of pain following photorefractive keratectomy.
      ,
      • Cherry P.M.H.
      The treatment of pain following excimer laser photorefractive keratectomy: additive effect of local anesthetic drops, topical diclofenac, and bandage soft contact.
      ]. Both studies found that patients treated with both topical agents and BSCLs experienced less pain than patients treated with both agents and no lens, supporting the practice of using BSCLs following PRK. More recently, an evaluation of the use of BSCLs soaked in 0.45 % ketorolac [
      • Shetty R.
      • Dalal R.
      • Nair A.
      • Khamar P.
      • D’Souza S.
      • Vaishnav R.
      Pain management after photorefractive keratectomy.
      ] found that the use of the ketorolac-soaked lens significantly reduced postoperative pain.
      Despite the theoretical benefits of increased oxygen transmissibility with silicone hydrogel lenses, medium quality evidence studies are equivocal as far as the superiority of silicone hydrogels to hydrogels. In a prospective study of 100 patients randomised to either a silicone hydrogel or hydrogel lens, the silicone hydrogel lens outperformed its hydrogel competitor [
      • Engle A.T.
      • Laurent J.M.
      • Schallhorn S.C.
      • Toman S.D.
      • Newacheck J.S.
      • Tanzer D.J.
      • et al.
      Masked comparison of silicone hydrogel lotrafilcon A and etafilcon A extended-wear bandage contact lenses after photorefractive keratectomy.
      ]. However, a subsequent study’s retrospective analysis of epithelial healing after PRK in 206 patients did not find a difference in the rate of re-epithelialisation [
      • Edwards J.
      • Bower K.
      • Sediq D.
      • Burka J.
      • Stutzman R.
      • Vanroekel C.
      • et al.
      Effects of lotrafilcon a and omafilcon a bandage contact lenses on visual outcomes after photorefractive keratectomy.
      ]. While patient-reported pain levels and the frequency of haze were higher with the hydrogel lens, more infiltrates were seen with wear of the silicone hydrogel lens [
      • Edwards J.
      • Bower K.
      • Sediq D.
      • Burka J.
      • Stutzman R.
      • Vanroekel C.
      • et al.
      Effects of lotrafilcon a and omafilcon a bandage contact lenses on visual outcomes after photorefractive keratectomy.
      ].
      While more recent studies have primarily used silicone hydrogel lenses, there are very few comparative controlled studies that support the use of a specific silicone hydrogel lens after PRK. Available evidence suggests that second and third generation silicone hydrogel lenses may confer some advantages in terms of pain and discomfort; however, re-epithelialisation is unchanged. The data reporting and comparing various SiHy lenses after PRK are summarised in Table 1.
      Table 1Summary of prospective published studies (all case control or cohort studies) comparing the efficacy of various silicone hydrogel contact lenses after PRK.
      Author, YearStudy designNumber of patients (n)Materials comparedStudy outcomes
      Grentzelos et al., 2009 [
      • Grentzelos M.A.
      • Plainis S.
      • Astyrakakis N.I.
      • Diakonis V.F.
      • Kymionis G.D.
      • Kallinikos P.
      • et al.
      Efficacy of 2 types of silicone hydrogel bandage contact lenses after photorefractive keratectomy.
      ]
      Randomised, Contralateral44Lotrafilcon ANo differences in re-epithelialisation
      Lotrafilcon B
      Razmjoo et al., 2012 [
      • Razmjoo H.
      • Abdi E.
      • Atashkadi S.
      • Reza A.
      • Reza P.
      • Akbari M.
      Comparative study of two silicone hydrogel contact lenses used as bandage contact lenses after photorefractive keratectomy - PubMed.
      ]
      Randomised, Contralateral44Senofilcon APain and discomfort lowest with senofilcon A, no difference in epithelial healing
      Lotrafilcon A
      Plaka et al., 2013 [
      • Plaka A.
      • Grentzelos M.A.
      • Astyrakakis N.I.
      • Kymionis G.D.
      • Pallikaris I.G.
      • Plainis S.
      Efficacy of two silicone-hydrogel contact lenses for bandage use after photorefractive keratectomy.
      ]
      Non-randomised Contralateral47Lotrafilcon BFaster epithelial healing with asmofilcon in first 3 days; no other differences noted
      Asmofilcon A
      Taylor et al., 2014 [
      • Taylor K.
      • Caldwell M.
      • Payne A.
      • Apsey D.
      • Townley J.
      • Reilly C.
      • et al.
      Comparison of 3 silicone hydrogel bandage Soft contact lenses for pain control after photorefractive keratectomy.
      ]
      Randomised, Contralateral45Senofilcon APain levels highest with balafilcon A > lotrafilcon A > senofilcon A
      Balafilcon A
      Lotrafilcon A
      Mukherjee et al., 2015 [
      • Mukherjee A.
      • Ioannides A.
      • Aslanides I.
      Comparative evaluation of Comfilcon A and Senofilcon A bandage contact lenses after transepithelial photorefractive keratectomy.
      ]
      Randomised, Contralateral24Comfilcon AA reduction in pain with wear of the senofilcon A lens; no difference in epithelial healing
      Senofilcon A
      Eliaçik et al., 2015 [
      • Eliaçik M.
      • Erdur S.K.
      • Gülkilik G.
      • Özsütçü M.
      • Karabela Y.
      Compare the effects of two silicone-hydrogel bandage contact lenses on epithelial healing after photorefractive keratectomy with anterior segment optical coherence tomography.
      ]
      Randomised, Contralateral21Lotrafilcon BNo difference in overall healing rate, size of epithelial defect through postop day 3 and discomfort were both reduced with comfilcon A
      Comfilcon A
      Mohammadpour et al. 2015 [
      • Mohammadpour M.
      • Amouzegar A.
      • Hashemi H.
      • Jabbarvand M.
      • Kordbacheh H.
      • Rahimi F.
      • et al.
      Comparison of lotrafilcon B and balafilcon a silicone hydrogel bandage contact lenses in reducing pain and discomfort after photorefractive keratectomy: a contralateral eye study.
      ]
      Randomised, Contralateral60Balafilcon ALess pain with lotrafilcon A; Foreign body sensation with balafilcon A
      Lotrafilcon A
      Mohammadpour et., 2018 [
      • Mohammadpour M.
      • Heidari Z.
      • Hashemi H.
      • Asgari S.
      Comparison of the lotrafilcon B and comfilcon a silicone hydrogel bandage contact lens on postoperative ocular discomfort after photorefractive keratectomy.
      ]
      Randomised, Contralateral60Lotrafilcon BNo differences in pain or ocular discomfort
      Comfilcon A
      Yuksel et al., 2019 [
      • Yuksel E.
      • Ozulken K.
      • Uzel M.
      • Taslipinar Uzel A.
      • Aydoğan S.
      Comparison of samfilcon a and lotrafilcon B silicone hydrogel bandage contact lenses in reducing postoperative pain and accelerating Re-epithelialization after photorefractive keratectomy.
      ]
      Randomised, Contralateral34Samfilcon ASome differences in healing and pain on postop day 2; no differences between lens types by postop day 3
      Lotrafilcon B
      Duru et al., 2020 [
      • Duru Z.
      • Duru N.
      • Ulusoy D.
      Effects of senofilcon A and lotrafilcon B bandage contact lenses on epithelial healing and pain management after bilateral photorefractive keratectomy.
      ]
      Randomised, Contralateral43Senofilcon ALess pain and tearing over first 48 h postop with senofilcon A, no difference in epithelial healing
      Lotrafilcon B
      Bagherian et al., 2020 [
      • Bagherian H.
      • Zarei-Ghanavatim S.
      • Momeni-Moghaddam H.
      • Wolffsohn J.
      • Sedaghat M.
      • Naroo S.
      • et al.
      Masked comparison of two silicone hydrogel bandage contact lenses after photorefractive keratectomy.
      ]
      Randomised, Contralateral45Both generations of balafilcon ANo difference in epithelial healing, second generation lenses tended to have increased deposits
      Duru et al., 2020 [
      • Duru N.
      • Altunel O.
      • Sırakaya E.
      • Küçük B.
      Comparison of the balafilcon a and samfilcon a lenses on postoperative pain control and epithelial healing time after photorefractive keratectomy: a contralateral eye study.
      ]
      Randomised, Contralateral37Balafilcon ABetter comfort with samfilcon A, no differences in epithelial healing
      Samfilcon A
      Two medium quality evidence studies have reported on the efficacy of investigational silicone shields following PRK. The first study concluded that the investigational device had a relatively good margin of safety, however no comparator BSCL was used [
      • Sáles C.
      • Manche E.
      Prospective evaluation of a novel silicone corneal shield after PRK: 6-month efficacy, safety, and predictability outcomes.
      ]. A subsequent study included the use of a comparator lens and found an improvement in visual recovery with the silicone shield; however, ocular discomfort was greater compared to the BSCL and no statistical differences were noted in epithelial healing [
      • Hirabayashi K.
      • Sáles C.
      • Slade S.
      • Manche E.
      Prospective, randomized, eye-to-eye comparison of a new silicone corneal shield versus conventional bandage contact lens after photorefractive keratectomy.
      ].
      The efficacy of sutureless cryopreserved amniotic membrane placed at the time of the procedure on epithelial healing compared to BSCL after PRK found that the amniotic membrane was not superior to a BSCL in the promotion of epithelial healing after PRK [
      • Vlasov A.
      • Sia R.
      • Ryan D.
      • Mines M.
      • Stutzman R.
      • Rivers B.
      • et al.
      Sutureless cryopreserved amniotic membrane graft and wound healing after photorefractive keratectomy.
      ]. Similarly, a cohort study found that the use of sutureless amniotic membrane was not more effective than BSCLs in preventing haze after PRK [
      • Cox A.
      • Sia R.
      • Purt B.
      • Ryan D.
      • Beydoun H.
      • Colyer M.
      • et al.
      Assessment of corneal haze after PRK and the effect of sutureless amniotic membrane graft by corneal densitometry.
      ]. In a similar study, the use of cultured human allogeneic epidermal keratinocyte onlays as a method to promote healing and reduce pain was compared to BSCL wear [
      • Chung S.
      • Kim E.
      • Ryu I.
      • Kim J.
      • Lee H.
      Effectiveness of cultured human keratinocyte onlays on epithelial healing and clinical outcome after photorefractive keratectomy.
      ]. Patients were randomised into one of three treatment groups with the cultured human allogeneic epidermal keratinocyte onlays with BSCL, with amniotic membrane and a BSCL, or a group with BSCL alone. Study findings demonstrated that a shorter duration of lens wear was required for the group treated with the amniotic membrane, but no other differences were noted.
      Lens fitting is also an important determinant for managing postoperative pain in PRK. In a prospective study, 140 patients were fitted with a silicone hydrogel lens available in two base curves: 8.4 mm and 8.8 mm [
      • Taylor K.
      • Molchan R.
      • Townley J.
      • Caldwell M.
      • Panday V.
      The effect of silicone hydrogel bandage soft contact lens base curvature on comfort and outcomes after photorefractive keratectomy.
      ]. The relationship between the lens base curve and anterior corneal curvature impacted comfort, with corneas with a postoperative keratometry (K) value of less than 38 dioptres (8.8 mm) having better pain outcomes when wearing the 8.8 mm base curve, whereas steeper corneas with a postop K value greater than 42 dioptres (8.04 mm) did better with the 8.4 mm lens [
      • Taylor K.
      • Molchan R.
      • Townley J.
      • Caldwell M.
      • Panday V.
      The effect of silicone hydrogel bandage soft contact lens base curvature on comfort and outcomes after photorefractive keratectomy.
      ]. Misalignment between the base curve of the contact lens and corneal curvature was a factor driving premature lens loss. This study highlights that lens fit, as opposed to lens material or Dk, warrants consideration and study in the selection of BSCL after PRK.
      To further investigate the parameters associated with BSCL wear and pain control, a prospective study examined the timing of BSCL removal in 260 eyes of 130 patients, removing the lens either on day 4 or day 7 post-operatively [
      • Mohammadpour M.
      • Shakoor D.
      • Hashemi H.
      • Aghaie Meybodi M.
      • Rajabi F.
      • Hosseini P.
      Comparison of bandage contact lens removal on the fourth versus seventh postoperative day after photorefractive keratectomy: a randomized clinical trial.
      ]. They found no differences in pain between the two groups, although interestingly, the group in which the BSCL was removed on day 4 post-op had an increase in the frequency of complications, including filamentary keratitis, corneal erosion, and haze. This finding suggests that longer postoperative lens wear was associated with fewer complications. Visual recovery at one month was also improved in the seven-day BSCL group, although this change was not evident at three months.
      A prospective study examined if the temperature of the irrigating solution and BSCL had an effect on post-PRK pain, with one group receiving chilled (2-5°C) balanced salt solution and a chilled BSCL, while the other group received the solution and BSCL at room temperature (21–23 °C) [
      • Zarei-Ghanavati S.
      • Nosrat N.
      • Morovatdar N.
      • Abrishami M.
      • Eghbali P.
      Efficacy of corneal cooling on postoperative pain management after photorefractive keratectomy: a contralateral eye randomized clinical trial.
      ]. No difference in post-operative pain measures were noted between the two groups.

      2.1.2 Laser assisted in situ keratomileusis (LASIK)

      LASIK is a procedure in which a corneal flap is cut using a blade or femto-laser under which an excimer laser is used to ablate corneal stroma, reshaping the cornea and altering its optical power. There is insufficient evidence to support the routine use of BSCLs following LASIK. A controlled study of the use of hydrogel BSCLs after LASIK in 200 myopic eye found that the majority of patients did not experience better postoperative comfort from the application of a BSCL after LASIK, nor did the BSCL protect from the occurrence of microstriae [
      • Sekundo W.
      • Dick H.
      • Meyer C.
      Benefits and side effects of bandage soft contact lens application after LASIK: a prospective randomized study.
      ]. Another study compared the use of BSCLs to no lens wear immediately following LASIK and reported that 29 % of patients were intolerant to BSCLs, necessitating removal at one hour [
      • Orucov F.
      • Frucht-Pery J.
      • Raiskup F.
      • Strasman E.
      • Landau D.
      • Solomon A.
      Quantitative assessment of bandage soft contact lens wear immediately after LASIK.
      ]. The authors concluded that BSCL wear was effective for up to four hours after LASIK to decrease symptoms, while flap oedema and the presence of mucoid secretions were limitations of overnight wear. In terms of pain control, a prospective investigation of the efficacy of BSCLs after LASIK compared to topical medications on the first postoperative day [
      • Ahmed I.I.K.
      • Breslin C.W.
      Role of the bandage soft contact lens in the postoperative laser in situ keratomileusis patient.
      ] concluded that the use of topical medications was superior to the BSCL in terms of pain control and visual acuity. Additionally, patients preferred not wearing a BSCL.
      The use of BSCLs after LASIK can alter corneal topography and increase corneal oedema, reducing uncorrected distance visual acuity [
      • Seguí-Crespo M.
      • Parra Picó J.
      • Ruíz Fortes P.
      • Artola Reig A.
      • Blanes-Mompó F.J.
      • Pérez-Cambrodí R.J.
      Usefulness of bandage contact lenses in the immediate postoperative period after uneventful myopic LASIK.
      ]. The mechanism for this was both an increase in corneal asphericity, likely due to the mechanical pressure of the CL, and corneal flap oedema. The authors speculated that the oedema in the flap was due to preservatives in the topical medications. The finding of oedema in the flap was consistent with that reported by another group [
      • Orucov F.
      • Frucht-Pery J.
      • Raiskup F.
      • Strasman E.
      • Landau D.
      • Solomon A.
      Quantitative assessment of bandage soft contact lens wear immediately after LASIK.
      ].
      Some beneficial effects of BSCLs on wound healing after LASIK have been reported. A prospective, randomised study evaluated the effect of a BSCL on fibrosis at the flap margin with 41 patients (82 eyes) fitted with a BSCL in one eye but not in the contralateral, control eye [
      • Zhao L.
      • Li L.
      • Liu J.
      • Li P.
      Bandage contact lens application reduces fibrotic wound healing of flap margins after FS-LASIK: a prospective randomized clinical trial.
      ]. Pain and photophobia were milder in the eyes fitted with a BSCL than those with no BSCL, however the BSCL was associated with a foreign body sensation. While the BSCL did appear to improve healing at the flap margin, there were no differences in any of the other outcome measures at six months.
      Evidence supporting the use of BSCLs for the prevention of epithelial ingrowth is equivocal based on three retrospective reports in the literature. The largest of these evaluated 16,702 eyes in 12,485 patients over a ten-year period who underwent an enhancement [
      • Ortega-Usobiaga J.
      • Baviera-Sabater J.
      • Llovet-Osuna F.
      • González-López F.
      • Bilbao-Calabuig R.
      • Llovet-Rausell A.
      • et al.
      Outcomes of flap lift laser in situ keratomileusis enhancements in a large patient population: does application of a bandage contact Lens affect incidence of epithelial ingrowth?.
      ]. No differences were found in visual acuity or the rate of epithelial ingrowth between eyes that did or did not receive BSCL. The second, much smaller study also looked at the rate of epithelial ingrowth following an enhancement [
      • Chan C.
      • Boxer Wachler B.
      Comparison of the effects of LASIK retreatment techniques on epithelial ingrowth rates.
      ]. While the authors reported a potential trend towards an increase in epithelial ingrowth in the BSCL group, the study groups were small and there were no statistical differences reported. A third earlier study retrospectively evaluated the rate of epithelial ingrowth after LASIK included 783 eyes over a three-year study period, including eyes undergoing primary procedure and 108 undergoing enhancement [
      • Walker M.
      • Wilson S.
      Incidence and prevention of epithelial growth within the interface after laser in situ keratomileusis.
      ]. All eyes were given a BSCL for the first day after surgery. In this cohort, only three eyes developed epithelial ingrowth Due to the small number of cases reported, the authors concluded that extensive cleaning of the stromal interface during surgery combined with BSCLs may decrease the rate of epithelial ingrowth, although there was no control group with no lens for comparison.
      Only one report was found on the use of BSCLs in epi-LASIK [
      • Kim J.S.
      • Na K.S.
      • Joo C.K.
      Base curves of therapeutic lenses and their effects on post Epi-LASIK vision and pain: a prospective randomized clinical trial.
      ]. This prospective study evaluated the effects of two different base curves (8.4 mm and 8.8 mm) on the corneal epithelium and postoperative pain. Twenty-seven patients were fitted with both base curves in a contralateral fashion. There were no differences in any of the outcome measures, except for uncorrected distance visual acuity, with a statistically significant improvement with the 8.8 mm base curve on day four postop visit that was no longer evident by day seven. Similarly, a significantly significant improvement in uncorrected visual acuity was noted with the 8.8 mm base curve lens in patients with higher levels of myopia preoperatively and keratometry measurements of ≥ 43 dioptres at day four post op but was no longer significant at day seven.
      There is medium quality evidence supporting the use of BSCLs in the management of post-LASIK complications. In a report of 5896 eyes that had LASIK using a microkeratome, 95 eyes had intra-operative epithelial damage [
      • Smirennaia E.
      • Sheludchenko V.
      • Kourenkova N.
      • Kashnikova O.
      Management of corneal epithelial defects following laser in situ keratomileusis.
      ]. BSCLs were used to treat epithelial defects that were larger than three mm in size. All of these eyes healed in 1–3 days; 3 eyes with 4−5 mm defect were left with visually symptomatic irregular or against-the-rule astigmatism that was successfully treated with transepithelial phototherapeutic keratectomy. Another report of 5566 eyes that underwent LASIK using a microkeratome evaluated over a one-year period eight eyes that had recurrent epithelial loosening [
      • Oruçoğlu F.
      • Kenduşim M.
      • Ayoglu B.
      • Toksu B.
      • Goker S.
      Incidence and management of epithelial loosening after LASIK.
      ]. Lubrication and BSCLs were used in 4 eyes with the remaining 4 requiring anterior stromal puncture plus wear of BSCL for 1 month for resolution of symptoms. Additionally, a case of blunt trauma leading to a corneal flap dehiscence in a 32-year-old man with a history of LASIK was successfully treated with a BSCL [
      • Iskeleli G.
      • Ozkok A.
      • Cicik E.
      Traumatic corneal flap dehiscence 6 years after LASIK.
      ].
      No differences were found in the incidence of corneal epithelial ingrowth and in visual outcomes after enhancement by flap lift when comparing those that were fitted in a BSCL after the procedure to those who were not [
      • Ortega-Usobiaga J.
      • Baviera-Sabater J.
      • Llovet-Osuna F.
      • González-López F.
      • Bilbao-Calabuig R.
      • Llovet-Rausell A.
      • et al.
      Outcomes of flap lift laser in situ keratomileusis enhancements in a large patient population: does application of a bandage contact Lens affect incidence of epithelial ingrowth?.
      ]. Additionally, bacterial contaminants on used bandage lenses after LASIK or PRK have been characterised, but have not necessarily been associated with complications as usually only ocular commensal microorganisms are isolated [
      • Detorakis E.T.
      • Siganos D.S.
      • Houlakis V.M.
      • Kozobolis V.P.
      • Pallikaris L.G.
      Microbiological examination of bandage soft contact lenses used in laser refractive surgery.
      ,
      • Dantas P.E.C.
      • Nishiwaki-Dantas M.C.
      • Ojeda V.H.O.
      • Holzchuh N.
      • Mimica L.J.
      Microbiological study of disposable soft contact lenses after photorefractive keratectomy.
      ,
      • Pereira C.E.G.
      • Hida R.Y.
      • Silva C.B.
      • De Andrade M.R.
      • Fioravanti-Lui G.A.
      • Lui-Netto A.
      Post-photorefractive keratectomy contact lens microbiological findings of individuals who work in a hospital environment.
      ,
      • Liu X.
      • Wang P.
      • Kao A.A.
      • Jiang Y.
      • Li Y.
      • Long Q.
      Bacterial contaminants of bandage contact lenses used after laser subepithelial or photorefractive keratectomy.
      ]

      2.1.3 Laser epithelial keratomileusis (LASEK)

      LASEK is a procedure in which an “epithelium only” flap is created under which the stromal ablation is performed. Only four studies to date have evaluated the use of BSCLs following LASEK. One study demonstrated that SiHy BSCLs were well tolerated and effective in patients undergoing LASEK, however it is important to note that no comparator lens or control group were used [
      • Szaflik J.P.
      • Ambroziak A.M.
      • Szaflik J.P.
      Therapeutic use of a lotrafilcon A silicone hydrogel soft contact lens as a bandage after LASEK surgery.
      ]. Two other research groups later compared the use of hydrogel and SiHy lenses after LASEK. Both groups concluded that SiHy lenses were superior to hydrogels as BSCLs after LASEK [
      • Xie W.
      • Zeng J.
      • Cui Y.
      • Li J.
      • Li Z.
      • Liao W.
      • et al.
      Comparation of effectiveness of silicone hydrogel contact lens and hydrogel contact lens in patients after LASEK.
      ]. In the final study, the efficacy of two different generations of SiHy lenses were evaluated [
      • Qu X.
      • Dai J.
      • Jiang Z.
      • Qian Y.
      Clinic study on silicone hydrogel contact lenses used as bandage contact lenses after LASEK surgery.
      ]. Greater discomfort and an increase in deposits on the lens surface were found with wear of a first-generation silicone hydrogel compared to the second-generation lens material. Whether the advantage is based on oxygen transmission, modulus, tendency to deposits, or another material feature remains unknown.

      2.1.4 Phototherapeutic keratectomy (PTK)

      PTK is a procedure in which epithelial debridement and excimer laser ablation are used to treat anterior corneal disease including corneal dystrophies and scarring. Most evidence supporting the use of BSCLs after PTK ablation comes from prior work evaluating their use after PRK. A small case series investigating the use of BSCLs after PTK on patients with recurrent corneal erosions reported that eight eyes presented with erosions secondary to bullous keratopathy and all patients responded well to PTK with BSCLs [
      • Lin P.Y.
      • Wu C.C.
      • Lee S.M.
      Combined phototherapeutic keratectomy and therapeutic contact lens for recurrent erosions in bullous keratopathy.
      ] In a small case series on the use of PTK in children, five eyes from five children (six to eight years of age) with superficial anterior scarring were treated to prevent the development of amblyopia [
      • Kollias A.
      • Spitzlberger G.
      • Thurau S.
      • Gruterich M.
      • Lackerbauer C.
      Phototherapeutic keratectomy in children.
      ]. All eyes were fitted with BSCLs postoperatively along with topical antibiotics, steroids, and artificial tears. Four eyes showed an improvement in best corrected visual acuity. There was no mention of the specific BSCL that was used.

      2.2 Corneal Collagen Crosslinking (CXL)

      BSCLs are standard practice in CXL with epithelium removal (epi-off) to promote epithelial healing and reduce postoperative pain [
      • Pron G.
      • Ieraci L.
      • Kaulback K.
      • Secretariat M.A.
      • Ontario H.Q.
      Collagen cross-linking using riboflavin and ultraviolet-A for corneal thinning disorders: an evidence-based analysis.
      ,
      • Wollensak G.
      Crosslinking treatment of progressive keratoconus: new hope.
      ]. The only studies addressing the effects of BSCLs following CXL are focused on the risk of infection, which remains very low (0.0017 %–0.71 %) [
      • Tzamalis A.
      • Romano V.
      • Cheeseman R.
      • Vinciguerra R.
      • Batterbury M.
      • Willoughby C.
      • et al.
      Bandage contact lens and topical steroids are risk factors for the development of microbial keratitis after epithelium-off CXL.
      ,
      • Shetty R.
      • Kaweri L.
      • Nuijts R.
      • Nagaraja H.
      • Arora V.
      • Kumar R.
      Profile of microbial keratitis after corneal collagen cross-linking.
      ]. The use of steroids and a BSCL was the largest risk factor identified for infection after surgery [
      • Tzamalis A.
      • Romano V.
      • Cheeseman R.
      • Vinciguerra R.
      • Batterbury M.
      • Willoughby C.
      • et al.
      Bandage contact lens and topical steroids are risk factors for the development of microbial keratitis after epithelium-off CXL.
      ]. Rates of infection were higher than in PRK for reasons unknown, however it is speculated that the increased incidence of atopy among patients with keratoconus may be contributory.
      One of the few studies to evaluate the use of BSCLs on pain control and re-epithelialisation after CXL examined the use of balafilcon A and hioxifilcon A lens materials, and reported that the epithelium underwent complete healing by day three with no differences in pain [
      • Kocluk Y.
      • Cetinkaya S.
      • Sukgen E.
      • Günay M.
      • Mete A.
      Comparing the effects of two different contact lenses on corneal Re-Epithelialization after corneal collagen cross-linking.
      ]. Collagen shields have also been tested for their efficacy in managing epithelial defects after CXL [
      • Guber I.
      • Bergin C.
      • Malde S.
      • Guber J.
      • Hamada S.
      • Lake D.
      First experience with oasis collagen SOFT SHIELD ® for epithelial defect after corneal cross-linking.
      ]. In a prospective study, all epithelial defects were fully healed by day four, with complete re-epithelialisation at one month. While the authors demonstrated that the collagen shield was effective, there was no comparator BSCL or non-treated control.

      2.3 Ethylenediamine-tetraacetic acid (EDTA) chelation

      For patients with band keratopathy, the corneal epithelium is removed by mechanical debridement and the cornea is then treated with EDTA to remove calcium deposits located within the anterior stroma and anterior limiting lamela membrane. Historically, either a BSCL is inserted or the eye is patched after the procedure. In recent years, there has been a shift towards increased BSCL use. Evidence supporting the efficacy of BSCL after EDTA chelation is scant. In a small cohort, 19 % ethanol was used to detach the epithelium to prevent the development of a post-procedure corneal abrasion and the clinical experience of three patients fitted with silicone hydrogel BSCL for one to two weeks following the procedure was described [
      • De Ortueta D.
      • Schreyger F.
      • Baatz H.
      Band keratopathy: a modified treatment.
      ]. In this small cohort, the BSCL was very effective in reducing postoperative pain. A retrospective study evaluated 89 cases that were all fitted with a BSCL postop and focused on the recurrence of disease; however, no mention of the BSCL type or impact of the BSCL on procedural outcomes or ocular discomfort were noted [
      • Al-Hity A.
      • Ramaesh K.
      • Lockington D.
      EDTA chelation for symptomatic band keratopathy: results and recurrence.
      ].

      2.4 Persistent epithelial defects (PED)

      Corneal epithelial defects are classified as PEDs when they are non-responsive to treatment after two weeks [
      • McCulley J.
      • Horowitz B.
      • Husseini Z.
      • Horowitz M.
      Topical fibronectin therapy of persistent corneal epithelial defects.
      ]. PEDs can occur from a myriad of aetiologies. These include iatrogenic (e.g. toxic keratitis secondary to chronic use of medications containing benzalkonium chloride), surgical complications, neurotrophic keratopathy, ocular surface disease, infection, and trauma [
      • Vaidyanathan U.
      • Hopping G.C.
      • Liu H.Y.
      • Somani A.N.
      • Ronquillo Y.C.
      • Hoopes P.C.
      • et al.
      Persistent corneal epithelial defects: a review article.
      ]. Importantly, if the epithelial defect is not properly treated, it can progress to ulceration and/or scarring. Past treatments involved pressure patching along with antibiotics and cycloplegics. BSCLs are now considered a standard therapy and are used as part of a conservative management approach, along with lubrication, punctal occlusion, and epithelial debridement [
      • Vaidyanathan U.
      • Hopping G.C.
      • Liu H.Y.
      • Somani A.N.
      • Ronquillo Y.C.
      • Hoopes P.C.
      • et al.
      Persistent corneal epithelial defects: a review article.
      ,
      • Katzman L.
      • Jeng B.
      Management strategies for persistent epithelial defects of the cornea.
      ]. The BSCL protects from damage from the eyelid that may contribute to mechanical erosions, thus aiding in epithelial healing. BSCLs are superior to pressure patching because the eye can be monitored without removal. Soft contact lenses are routinely used in these cases since standard rigid corneal lenses are small, move too much, and are too abrasive for a PED. Drawbacks to using BSCLs for PEDs include lens displacement and risk of microbial keratitis [
      • Blackmore S.J.
      The use of contact lenses in the treatment of persistent epithelial defects.
      ].
      Medium quality evidence exists to support the use of BSCLs in the treatment of PEDs. In a prospective study, all patients with PEDs following vitreoretinal surgery that showed no improvement after patching for two weeks were fitted with BSCLs, though the exact lens type not specified [
      • Oskouee S.
      • Amuzadeh J.
      • Rajabi M.
      Bandage contact lens and topical indomethacin for treating persistent corneal epithelial defects after vitreoretinal surgery.
      ]. Patients were then treated with topical 1 % indomethacin or artificial tears. No differences in epithelial staining were noted between the groups, but pain was reduced in patients that used both the topical NSAID and BSCL. It was noted that NSAID use was associated with the development of fine stromal opacities which resolved over time.
      Early prospective study of a balafilcon A lens in an overnight wear modality of 3–90 days for therapeutic indications including PEDs found that 15 of 19 patients with PEDs demonstrated complete healing and BSCLs were well tolerated; however, of note, two eyes did develop MK [
      • Arora R.
      • Jain S.
      • Monga S.
      • Narayanan R.
      • Raina U.
      • Mehta D.
      Efficacy of continuous wear PureVision contact lenses for therapeutic use.
      ]. A similar study used the lotrafilcon A lens, also in an overnight wear modality for 3 days to 13 months, as a BSCL for a variety of ocular surface diseases, including four PEDs [
      • Kanpolat A.
      • Uçakhan ÖÖ
      Therapeutic Use of Focus® Night and DayTM Contact Lenses.
      ]. All PEDs were successfully healed with good tolerance and comfort of the BSCL and without sight-threatening complications or vision loss. Due to the successful study outcome, the authors theorised that the benefit of the longer wear schedule was advantageous as it reduced the risk of epithelial damage associated with more frequent replacement.
      A retrospective review compared the use of a porcine collagen shield (Bausch &Lomb, Rochester, NY) worn for 24 h to a standard hydrogel BSCL for PEDs [
      • Groden L.
      • White W.
      Porcine collagen corneal shield treatment of persistent epithelial defects following penetrating keratoplasty.
      ]. Patients that wore the BSCLs had complete re-epithelialisation, whereas no healing was evident in patients wearing the collagen shield. In a small case series examining the use of a topical regenerative agent and a BSCL for the treatment of PEDs, all eyes and PEDs fully healed within three weeks with said treatment [
      • Kymionis G.
      • Liakopoulos D.
      • Grentzelos M.
      • Diakonis V.
      • Klados N.
      • Tsoulnaras K.
      • et al.
      Combined topical application of a regenerative agent with a bandage contact lens for the treatment of persistent epithelial defects.
      ]. Large diameter BSCLs have also been used following allogenic simple limbal epithelial transplantation for the treatment of PEDs with successful re-epithelialisation in 93 % of eyes [
      • Riedl J.C.
      • Musayeva A.
      • Wasielica-Poslednik J.
      • Pfeiffer N.
      • Gericke A.
      Allogenic simple limbal epithelial transplantation (alloSLET) from cadaveric donor eyes in patients with persistent corneal epithelial defects.
      ]. In this case series, all patients wore BSCLs, thus no control group was included.
      There is only weak evidence supports the successful use of BSCLs in conjunction with autologous serum eye drops. The first evaluation of the therapeutic efficacy of this treatment was in a small case series on six eyes with PEDs due to various aetiologies [
      • Schrader S.
      • Wedel T.
      • Moll R.
      • Geerling G.
      Combination of serum eye drops with hydrogel bandage contact lenses in the treatment of persistent epithelial defects.
      ]. All eyes resolved without complications and BSCLs were well tolerated, despite reports of white protein deposition on the BSCL surface. More recently, the efficacy of autologous serum and BSCLs for the therapeutic management of PEDs was studied [
      • Lee Y.K.
      • Lin Y.C.
      • Tsai S.H.
      • Chen W.L.
      • Chen Y.M.
      Therapeutic outcomes of combined topical autologous serum eye drops with silicone–hydrogel soft contact lenses in the treatment of corneal persistent epithelial defects: a preliminary study.
      ] and all twenty-one eyes that received 20 % autologous serum along with a silicone hydrogel BSCL demonstrated complete re-epithelialisation without recurrence during a 3 month follow-up period. A retrospective evaluation of 12 eyes with PEDs due to previous infectious events were similarly treated with complete resolution of the PED [
      • Wang W.
      • Lee Y.
      • Tsai S.
      • Lin Y.
      • Chen Y.
      Autologous serum eye drops combined with silicone hydrogen lenses for the treatment of postinfectious corneal persistent epithelial defects.
      ].
      While soft contact lenses are mostly used as BSCLs for the treatment of PEDs, published studies support the use of scleral lenses for the management of longstanding cases, even those that have failed with prior treatment. The first report regarding the use of scleral lenses for the treatment of PEDs found that scleral lenses promoted re-epithelialisation of the defect in a majority of cases, however four eyes (29 %) developed microbial keratitis [
      • Rosenthal P.
      • Cotter J.
      • Baum J.
      Treatment of persistent corneal epithelial defect with extended wear of a fluid-ventilated gas-permeable scleral contact lens.
      ]. A later report by Lim et al. evaluated clinical outcomes for PEDs treated with the Prosthetic Replacement of the Ocular Surface Ecosystem (PROSE) device, with daily cleaning and replenishment as well as the use of a prophylactic, non-preserved antibiotic in the reservoir [
      • Lim P.
      • Ridges R.
      • Jacobs D.
      • Rosenthal P.
      Treatment of persistent corneal epithelial defect with overnight wear of a prosthetic device for the ocular surface.
      ]. Unlike the prior study, most eyes had complete re-epithelialisation with no adverse events with the prophylactic antibiotic treatment. Other studies report success with the PROSE device for the treatment of PEDs and recurrent corneal erosion syndrome secondary to multiple aetiologies [
      • Ling J.
      • Gire A.
      • Pflugfelder S.
      PROSE therapy used to minimize corneal trauma in patients with corneal epithelial defects.
      ,
      • He X.
      • Donaldson K.E.
      • Perez V.L.
      • Sotomayor P.
      Case series: overnight wear of scleral lens for persistent epithelial defects.
      ,
      • Khan M.
      • Manuel K.
      • Vegas B.
      • Yadav S.
      • Hemmati R.
      • Al-Mohtaseb Z.
      Case series: extended wear of rigid gas permeable scleral contact lenses for the treatment of persistent corneal epithelial defects.
      ]. Interestingly, in one study, all were patients that had failed to heal with wear of a silicone hydrogel BSCL [
      • Ling J.
      • Gire A.
      • Pflugfelder S.
      PROSE therapy used to minimize corneal trauma in patients with corneal epithelial defects.
      ].

      2.5 Corneal abrasions and recurrent corneal erosion syndrome (RCES)

      RCES is a painful condition that often occurs upon awakening as a result of nocturnal drying. In addition to pain, hyperaemia, tearing, photophobia, and blurry vision are often present. BSCLs are routinely used in patients with RCES to protect the damaged epithelium and facilitate re-epithelialisation. They also help to mitigate pain. A 2018 Cochrane review of interventions for RCES found benefit of therapeutic contact lens over lubricant with no adverse effects, based on one study, (detailed below), using a modern lens that met criteria for inclusion in the review [
      • Watson S.L.
      • Leung V.
      Interventions for recurrent corneal erosions.
      ]. The ideal BSCL for treating RCES would have high oxygen transmissibility and a flat base curve [
      • Miller D.D.
      • Hasan S.A.
      • Simmons N.L.
      • Stewart M.W.
      Recurrent corneal erosion: a comprehensive review.
      ]. The preference towards the use of a flat base curve suggests that the mechanical contact from the flat lens is superior to a tight lens, although there is little evidence in the BSCL literature to support this and thus represents an area where further studies are needed. The primary risk of using BSCLs in patients with RCES remains infection, which is increased if steroids are used to help suppress inflammation [
      • Miller D.D.
      • Hasan S.A.
      • Simmons N.L.
      • Stewart M.W.
      Recurrent corneal erosion: a comprehensive review.
      ,
      • Liu C.
      • Buckley R.
      The role of the therapeutic contact lens in the management of recurrent corneal erosions: a review of treatment strategies - PubMed.
      ]. The largest retrospective study to evaluate BSCLs compared to other treatment modalities for RCES spanned an eight-year period [
      • Reidy J.
      • Paulus M.
      • Gona S.
      Recurrent erosions of the cornea: epidemiology and treatment.
      ]. During that time, 104 patients were evaluated and full re-epithelialisation was seen in all eyes wearing BSCLs. A randomized controlled trial (RCT) study also compared treatment with either ocular lubricants or a BSCL for patients with RCES [
      • Ahad M.
      • Anandan M.
      • Tah V.
      • Dhingra S.
      • Leyland M.
      Randomized controlled study of ocular lubrication versus bandage contact lens in the primary treatment of recurrent corneal erosion syndrome.
      ]. After three months, 71.4 % and 73.3 % of patients in the BSCL group and ocular lubricant group, respectively, showed complete re-epithelialisation. They further reported that wear of the BSCL enhanced the rate of re-epithelialisation. A report on the impact of long term overnight wear of the BSCL in patients with RCES found that 75 % of these patients had no further recurrences when followed over one year [
      • Fraunfelder F.W.
      • Cabezas M.
      Treatment of recurrent corneal erosion by extended-wear bandage contact lens.
      ].
      A retrospective analysis of the efficacy of a silicone hydrogel BSCL across three different clinical sites concluded that the lens was effective at managing patients with RCES [
      • Shafran T.
      • Gleason W.
      • Osborn Lorenz K.
      • Szczotka-Flynn L.B.
      Application of senofilcon A contact lenses for therapeutic bandage lens indications.
      ]. No controls or comparators were used in this study.
      There is medium quality evidence to support the use of BSCLs for traumatic corneal abrasions. The first report on this topic was in 1987, which compared the use of BSCLs to patching in patients with abrasions greater than four mm2 in size [
      • Acheson J.
      • Joseph J.
      • Spalton D.
      Use of Soft contact lenses in an eye casualty department for the primary treatment of traumatic corneal abrasions.
      ]. Overall, patients wearing BSCLs healed faster and experienced less pain. In studies using BSCLs combined with a topical NSAID to treat RCES, successful re-epithelialisation and a significant reduction in pain were reported [
      • Salz J.
      • Reader A.
      • Schwartz L.
      • Van Le K.
      Treatment of corneal abrasions with Soft contact lenses and topical diclofenac.
      ,
      • Donnenfeld E.
      • Selkin B.
      • Perry H.
      • Moadel K.
      • Selkin G.
      • Cohen A.
      • et al.
      Controlled evaluation of a bandage contact lens and a topical nonsteroidal anti-inflammatory drug in treating traumatic corneal abrasions.
      ]. In addition, patients wearing a BSCL were able to resume normal activities earlier than the patched group [
      • Donnenfeld E.
      • Selkin B.
      • Perry H.
      • Moadel K.
      • Selkin G.
      • Cohen A.
      • et al.
      Controlled evaluation of a bandage contact lens and a topical nonsteroidal anti-inflammatory drug in treating traumatic corneal abrasions.
      ]. However, at the same time, evidence emerged to suggest that pressure patch offers no advantage in the treatment of corneal abrasion, suggesting that the CL studies did not use the appropriate control group [
      • Kaiser P.K.
      A comparison of pressure patching versus no patching for corneal abrasions due to trauma or foreign body removal.
      ].
      A retrospective examination of all patients that presented with traumatic, non-infected corneal erosions over a five-year period found that, despite a large variation in defect size, all eyes wearing a BSCL re-epithelialised between one and three days [
      • Gilad E.
      • Bahar I.
      • Rotberg B.
      • Weinberger D.
      Therapeutic contact lens as the primary treatment for traumatic corneal erosions.
      ]. In agreement with these studies, a smaller retrospective study examined patients with traumatic corneal abrasions that presented to one of several U.S. military battalion aid stations [
      • Buglisi J.
      • Knoop K.
      • Levsky M.
      • Euwema M.
      Experience with bandage contact lenses for the treatment of corneal abrasions in a combat environment.
      ]. Successful re-epithelialisation with the BSCL was achieved in 87 % of patients.
      A later report on the efficacy of the same silicone hydrogel BSCL compared to patching for the treatment of traumatic erosions showed that patients wearing BSCL had less pain than those that were patched [
      • Triharpini N.
      • Gede Jayanegara I.
      • Handayani A.
      • Widiana I.
      Comparison between bandage contact lenses and pressure patching on the erosion area and pain scale in patients with corneal erosion.
      ]. The authors point out that the pressure patch had to be removed for the instillation of topical medications and was replaced at home by family members or the patient. Thus, the strength of the pressure patch may have varied and contributed to the differences reported.

      2.6 Over-tissue adhesive (glue) for corneal perforations and lacerations

      Fibrin and cyanoacrylate tissue adhesive are sometimes used in patients with corneal perforation. Depending on the size of the perforation and location within the cornea, tissue adhesive along with a BSCL may be sufficient to avoid the need for surgical intervention to stabilize the globe, with cyanoacrylate adhesive more effective than fibrin for larger perforations. The application of a BSCL is essential, as the surface of the adhesive is rough and may be dislodged by squeezing or blink [
      • Sharma A.
      • Kaur R.
      • Kumar S.
      • Gupta P.
      • Pandav S.
      • Patnaik B.
      • et al.
      Fibrin glue versus N-butyl-2-cyanoacrylate in corneal perforations.
      ,
      • Setlik D.
      • Seldomridge D.
      • Adelman R.
      • Semchyshyn T.
      • Afshari N.
      The effectiveness of isobutyl cyanoacrylate tissue adhesive for the treatment of corneal perforations.
      ,
      • Jhanji V.
      • Young A.L.
      • Mehta J.S.
      • Sharma N.
      • Agarwal T.
      • Vajpayee R.B.
      Management of corneal perforation.
      ]. There are numerous case reports/series that reported on the use of tissue glue with BSCLs [
      • Okabe M.
      • Kitagawa K.
      • Yoshida T.
      • Koike C.
      • Katsumoto T.
      • Fujihara E.
      • et al.
      Application of 2-octyl-cyanoacrylate for corneal perforation and glaucoma filtering bleb leak.
      ,
      • Siatiri H.
      • Moghimi S.
      • Malihi M.
      • Khodabande A.
      Use of sealant (HFG) in corneal perforations.
      ,
      • Moorthy S.
      • Jhanji V.
      • Constantinou M.
      • Beltz J.
      • Graue-Hernandez E.
      • Vajpayee R.
      Clinical experience with N-butyl cyanoacrylate tissue adhesive in corneal perforations secondary to herpetic keratitis.
      ,
      • Timlin H.M.
      • Hall H.N.
      • Foot B.
      • Koay P.
      Corneal perforation from peripheral ulcerative keratopathy in patients with rheumatoid arthritis: epidemiological findings of the British Ophthalmological Surveillance Unit.
      ,
      • Lee W.B.
      • O’Halloran H.S.
      • Grossniklaus H.E.
      Pellucid marginal degeneration and bilateral corneal perforation: case report and review of the literature.
      ]. Unfortunately, there is little detail or data as far as the optimal lens materials or fitting parameters to use in such of cases.

      2.7 Over-amniotic membrane – frozen, dried

      BSCLs have been used over amniotic membranes to promote retention. Many case studies and reviews report on the efficacy of amniotic membranes for the treatment of severe corneal epithelial defects, with and without stromal ulceration, and mention the use of BSCLs as part of their treatment protocols, but no studies have examined the benefits of their inclusion [
      • Borroni D.
      • Wowra B.
      • Romano V.
      • Boyadzhieva M.
      • Ponzin D.
      • Ferrari S.
      • et al.
      Simple limbal epithelial transplantation: a review on current approach and future directions.
      ,
      • Shalabi N.
      • Karp C.
      • Aziz H.
      • Jeng B.
      • Galor A.
      Superficial epithelial keratectomy, cautery, and amniotic membrane transplant for the treatment of painful bullous keratopathy in eyes with poor visual potential.
      ,
      • Gregory M.
      • Spiteri-Cornish K.
      • Hegarty B.
      • Mantry S.
      • Ramaesh K.
      Combined amniotic membrane transplant and anterior stromal puncture in painful bullous keratopathy: clinical outcome and confocal microscopy.
      ,
      • Letko E.
      • Stechschulte S.
      • Kenyon K.
      • Sadeq N.
      • Romero T.
      • Samson C.
      • et al.
      Amniotic membrane inlay and overlay grafting for corneal epithelial defects and stromal ulcers.
      ,
      • Sultana N.
      • Chaurasia S.
      • Ramappa M.
      High-resolution optical coherence tomography in a case of descemetocele managed with amniotic membrane transplantation.
      ].
      Only two studies were identified that support the use of BSCLs for the retention of amniotic membranes. An evaluation of the use of amniotic membranes for the treatment of epithelial defects due to surgery or unresponsive PEDs found that BSCLs were successfully used in 5 of 20 patients to maintain membrane position when the membrane only covered the cornea [
      • Gris O.
      • Del Campo Z.
      • Wolley-Dod C.
      • Güell J.
      • Bruix A.
      • Calatayud M.
      • et al.
      Amniotic membrane implantation as a therapeutic contact lens for the treatment of epithelial disorders.
      ]. The use of the BSCL increased retention time of the membrane and four of the five eyes re-epithelialised. A subsequent study in the UK investigated the efficacy of amniotic membrane transplantation with and without a BSCL [
      • Saw V.
      • Minassian D.
      • Dart J.
      • Ramsay A.
      • Henderson H.
      • Poniatowski S.
      • et al.
      Amniotic membrane transplantation for ocular disease: a review of the first 233 cases from the UK user group.
      ], and whilst there was a fairly high failure rate with the amniotic membrane, the application of a BSCL immediately post-operatively increased their likelihood of success.

      2.8 Post-operative use for comfort and healing

      There is moderate quality evidence for the use of BSCLs after phacoemulsification, penetrating keratoplasty, ptosis repair, and pterygium surgery.

      2.8.1 Phacoemulsification

      There are two recent cohort studies that report on the use of BSCLs after cataract surgery. In a comparison of clinical signs and symptoms of dry eye after phacoemulsification performed after retrobulbar block, those who wore BSCLs for 1 week had reduced signs and symptoms of dry eye when compared to those who wore an eye pad on the first day, at all evaluated time points (1 week, 1 month, 3 months) [
      • Shi D.
      • Song H.
      • Ding T.
      • Qiu W.
      • Wang W.
      Evaluation of the safety and efficacy of therapeutic bandage contact lenses on post-cataract surgery patients.
      ]. Another study examined the effects of BSCL wear after phacoemulsification on dry eye symptoms in patients with mild meibomian gland dysfunction [
      • Chen X.
      • Yuan R.
      • Sun M.
      • Chen X.
      • Lin S.
      • Ye J.
      • et al.
      Efficacy of an ocular bandage contact lens for the treatment of dry eye after phacoemulsification.
      ]. Dry eye symptoms were improved with BSCL use for 1 week versus no lens, with a statistically significant decrease in OSDI and subjective symptom scores at day 7 and day 14 post-op. No statistically significant difference was seen at day 1, day 30, and day 90 post-op.

      2.8.2 Penetrating keratoplasty

      BSCLs have been used after penetrating keratoplasty to enhance re-epithelialisation, prevent suture irritation, smooth irregularities in the wound margin, and to act as a tamponade for wound leaks since the mid-1970’s [
      • Aquavella J.V.
      New aspects of contact lenses in ophthalmology.
      ,
      • Aquavella J.V.
      • Shaw E.L.
      Hydrophilic bandages in penetrating keratoplasty.
      ,
      • Ramjiani V.
      • Fearnley T.
      • Tan J.
      A bandage contact lens prevents extrusion of ocular contents.
      ,
      • Van den Heurck J.
      • Boven K.
      • Anthonissen L.
      • Van Hoey M.
      • Koppen C.
      A case of late spontaneous post-radial keratotomy corneal perforation managed with specialty lenses.
      ]. In a randomised prospective study, 14 of 26 patients that underwent either deep anterior lamellar keratoplasty or penetrating keratoplasty were fitted with BSCLs and compared to a no lens control group [
      • Shimazaki J.
      • Shigeyasu C.
      • Saijo-Ban Y.
      • Dogru M.
      • Den S.
      Effectiveness of bandage contact lens application in corneal epithelialization and pain alleviation following corneal transplantation; prospective, randomized clinical trial.
      ]. No differences in any of the outcome measures were found between these two groups. The authors went on to speculate that postoperative pain may not be a factor due to damaged nerve endings as a result of keratoplasty, and thus BSCLs would not be beneficial for pain management in this setting. Moreover, in healthy patients, epithelialisation is usually complete approximately two days post-grafting. Unless the patient had an abnormal wound healing response or impaired tear secretion, BSCLs may not enhance healing. Other proposed factors that may influence the success of the BSCL are the health status of the donor and recipient corneas, surgical parameters, and postoperative therapeutic regimens used.
      A retrospective study designed to examine the frequency of PEDs after penetrating keratoplasty found that, of 11 eyes that were initially treated with a BCL (either a silicone hydrogel or scleral lens), four eyes were successfully healed in the first two weeks [
      • Fu Y.
      • Liu J.
      • Tseng S.
      Ocular surface deficits contributing to persistent epithelial defect after penetrating keratoplasty.
      ]. The remaining eyes needed additional treatment due to lagophthalmos or mechanical restriction.

      2.8.3 Ptosis repair

      A prospective report of 30 patients undergoing bilateral ptosis repair using a contralateral eye design found that the eye wearing the BSCL experienced less pain and ocular discomfort [
      • Adam R.
      • Harvey J.
      • Gould J.
      • Suntheralingam S.
      • Farrokhyar F.
      The role of postoperative bandage contact Lens in patients undergoing fasanella-servat ptosis repair.
      ]. A RCT of 30 eyes in 30 children undergoing surgery for congenital blepharoptosis found better tear film breakup time, tear meniscus height and less fluorescein staining, supporting a conclusion that BSCL wear after surgery was beneficial to protect the ocular surface [
      • Chen L.
      • Pi L.
      • Ke N.
      • Chen X.
      • Liu Q.
      The protective efficacy and safety of bandage contact lenses in children aged 5 to 11 after frontalis muscle flap suspension for congenital blepharoptosis: a single-center randomized controlled trial.
      ]. The use of a BSCL was reported as beneficial in prevention of epithelial breakdown that occurred in two cases where surgical intervention was required to treat exposure keratopathy after blepharoplasty [
      • Patel B.C.K.
      • Patipa M.
      • Anderson R.L.
      • McLeish W.
      Management of postblepharoplasty lower eyelid retraction with hard palate grafts and lateral tarsal strip.
      ]

      2.8.4 Pterygium surgery

      The use of BSCLs following pterygium surgery is equivocal. A comparison of the effects of BSCLs after pterygium surgery on re-epithelialisation and pain in 39 eyes (20 eyes randomised to the BSCL group, 19 to the no lens control group) found BSCL use significantly reduced pain and enhanced epithelial healing [
      • Chen D.
      • Lian Y.
      • Li J.
      • Ma Y.
      • Shen M.
      • Lu F.
      Monitor corneal epithelial healing under bandage contact Lens Using ultrahigh-resolution optical coherence tomography after pterygium surgery.
      ]. In a prospective study, pain, discomfort, and sleep quality during the initial 24 h after pterygium surgery were compared between subjects using BSCLs versus subjects who were patching [
      • Prat D.
      • Zloto O.
      • Ben Artsi E.
      • Ben Simon G.
      Therapeutic contact lenses vs. tight bandage patching and pain following pterygium excision: a prospective randomized controlled study.
      ]. Interestingly, pain levels were worse and sleep quality was decreased in the BSCL group. Thus, the authors concluded that, despite certain drawbacks, patching is superior to BSCLs after pterygium surgery. Another comparison of the use of BSCL wear versus patching on pain levels after pterygium removal reported an increase photophobia in the BSCL group on the day of surgery, but no other differences were found for any of the remaining outcome measures [
      • Yeung S.
      • Lichtinger A.
      • Kim P.
      • Elbaz U.
      • Ku J.
      • Teichman J.
      • et al.
      Efficacy and safety of patching vs bandage lens on postoperative pain following pterygium surgery.
      ].
      Another investigation of the efficacy of BSCLs compared to patching for pain control and re-epithelialisation was performed in 30 eyes, and, in contrast to previous studies, found that BSCL wear improved both pain and rate of re-epithelialisation when compared to patching over the first three post-operative days [
      • Daglioglu M.
      • Coskun M.
      • Ilhan N.
      • Tuzcu E.
      • Ilhan O.
      • Keskin U.
      • et al.
      The effects of soft contact lens use on cornea and patient’s recovery after autograft pterygium surgery.
      ]. Similarly, a study of “scleral” design large diameter (18.0, 18.5, and 19.0 mm) hydrogel lens after pterygium surgery reported that symptoms were less intense for patients who wore a lens compared to patients who wore no lens [
      • Arenas E.
      • Garcia S.
      A scleral soft contact lens designed for the postoperative management of pterygium surgery.
      ], with the larger diameter a plausible explanation for discordance with other studies.

      2.8.5 Intracorneal ring segments

      There is limited evidence that BSCLs can be worn after implantation of intracorneal ring segments to aid recovery and comfort [
      • Miranda D.
      • Sartori M.
      • Francesconi C.
      • Allemann N.
      • Ferrara P.
      • Campos M.
      Ferrara intrastromal corneal ring segments for severe keratoconus.
      ,
      • Rabinowitz Y.S.
      INTACS for keratoconus.
      ,
      • National Institute for Health and Excellence
      Interventional procedure overview of corneal implants for keratoconus.
      ,
      • Carrasquillo K.G.
      • Rand J.
      • Talamo J.H.
      Intacs for keratoconus and post-LASIK ectasia: mechanical versus femtosecond laser-assisted channel creation.
      ].

      2.9 Bleb leaks, perforations, and trauma

      There is medium quality evidence, for the use of BSCLs for the treatment of bleb leaks following trabeculectomy and in setting of wound leaks, trauma, and perforations.

      2.9.1 Bleb leaks

      BSCLs can be used for both early and late post-trabeculectomy bleb leaks. It is suggested that early bleb leaks occur within the first two months after surgery and are seen in up to 30 % of patients, whereas an older study suggests that the rate may be even higher (up to 56 %) in patients who undergo a fornix-based as opposed to a limbal-based procedure [
      • Alwitry A.
      • Rotchford A.
      • Patel V.
      • Abedin A.
      • Moodie J.
      • King A.
      Early bleb leak after trabeculectomy and prognosis for bleb failure.
      ,
      • Batterbury M.
      • Wishart P.
      Is high initial aqueous outflow of benefit in trabeculectomy?.
      ]. Late bleb leaks occur more than two months after surgery and are usually associated with the use of antimetabolites [
      • Greenfield D.S.
      • Liebmann J.M.
      • Jee J.
      • Ritch R.
      Late-onset bleb leaks after glaucoma filtering surgery.
      ,
      • Wilkins M.
      • Indar A.
      • Wormald R.
      Intra-operative mitomycin C for glaucoma surgery.