Performance and predictability of a new large diameter contact lens design in keratoconic corneae

Published:February 26, 2019DOI:



      To evaluate the clinical performance and predictability using corneal topography in the fitting of a new large-diameter rigid gas permeable (RGP) contact lens design in eyes with keratoconus (KCN).


      This study presents a review of eyes fitted with Alexa ES lenses for nonsurgical optimisation of visual correction. Anterior steep simulated keratometry (sim-K steep), corneal diameter (HVID), the Curvature at the apex in diopters (Cc), and distance from the corneal apex to the centre of the cornea (Lc) in millimetres derived from the Cone Location and Magnitude Index (CLMI) were recorded. Visual acuity, mean wearing time, final sagittal depth and adverse events were also recorded. Correlations between topographic indices and base curve were evaluated using the Pearson correlation coefficient.


      Forty-six eyes from 26 patients (19 males/ 7 females) were included. Mean visual acuity improved from 0.49 ± 0.32 with glasses, to -0.02 ± 0.10 with the contact lens. The mean daily wear time was 12.19 ± 1.96 hours. No complications were detected in 95.65% of the eyes [95% CI (83.9%-99.2%)] but two episodes of non-infectious keratitis. The average sagittal depth of the lenses fitted was 0.425 ± 0.15 mm, and it was positively correlated with the Cc value (r² = 0.66, p< 0.0001, n=46) derived from the CLMI index of the pre-fitting topography.


      Corneoscleral RGP contact lenses are a safe, and effective alternative for managing KCN patients to corneal lenses. Also, clinical data derived from the corneal topography could be used to help to decide the first diagnostic lens to be assessed, easing the overall fitting process.


      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Contact Lens and Anterior Eye
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Rabinowitz Y.S.
        Surv Ophthalmol. 1998; 42: 297-319
        • Edrington T.B.
        • Gundel R.E.
        • Libassi D.P.
        • Wagner H.
        • Pierce G.E.
        • Walline J.J.
        • et al.
        Variables affecting rigid contact lens comfort in the collaborative longitudinal evaluation of keratoconus (CLEK) study.
        Optom Vis Sci. 2004; 81: 182-188
        • Zadnik K.
        • Barr J.T.
        • Gordon M.O.
        • Edrington T.B.
        Biomicroscopic signs and disease severity in keratoconus. Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study Group.
        Cornea. 1996; 15: 139-146
        • Lass J.H.
        • Lembach R.G.
        • Park S.B.
        • Hom D.L.
        • Fritz M.E.
        • Svilar G.M.
        • et al.
        Clinical management of keratoconus. A multicenter analysis.
        Ophthalmology. 1990; 97: 433-445
        • Macsai M.S.
        • Varley G.A.
        • Krachmer J.H.
        Development of keratoconus after contact lens wear. Patient characteristics.
        Arch Ophthalmol. 1990; 108: 534-538
        • Weed K.H.
        • MacEwen C.J.
        • McGhee C.N.J.
        The Dundee University Scottish keratoconus study II: a prospective study of optical and surgical correction.
        Ophthalmic Physiol Opt. 2007; 27: 561-567
        • Mandell R.B.
        Contemporary management of keratoconus.
        Int Contact Lens Clin. 1997; 24: 43-55
        • Barr J.T.
        • Zadnik K.
        • Wilson B.S.
        • Edrington T.B.
        • Everett D.F.
        • Fink B.A.
        • et al.
        Factors associated with corneal scarring in the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study.
        Cornea. 2000; 19: 501-507
        • Barr J.T.
        • Wilson B.S.
        • Gordon M.O.
        • Rah M.J.
        • Riley C.
        • Kollbaum P.S.
        • et al.
        Estimation of the incidence and factors predictive of corneal scarring in the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study.
        Cornea. 2006; 25: 16-25
        • Downie L.E.
        • Lindsay R.G.
        Contact lens management of keratoconus.
        Clin Exp Optom. 2015; 98: 299-311
        • 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.
        Eye Contact Lens. 2005; 31: 130-134
        • Schornack M.M.
        • Patel S.V.
        Scleral lenses in the management of keratoconus.
        Eye Contact Lens. 2010; 36: 39-44
        • Fadel D.
        Modern scleral lenses: mini versus large.
        Cont Lens Ant. 2017; 40: 200-207
        • Bergmanson J.P.G.
        • Walker M.K.
        • Johnson L.A.
        Assessing scleral contact Lens satisfaction in a keratoconus population.
        Optom Vis Sci. 2016; 93: 855-860
        • Kim S.
        • Lee J.S.
        • Park Y.K.
        • Lee S.U.
        • Park Y.M.
        • Lee J.H.
        • et al.
        Fitting miniscleral contact lenses in Korean patients with keratoconus.
        Clin Exp Optom. 2017; 100 (August 23): 375-379
        • de Luis Eguileor B.
        • Etxebarria Ecenarro J.
        • Santamaria Carro A.
        • Feijoo Lera R.
        • et al.
        Irregular corneas: improve visual function with scleral contact lenses.
        Eye Contact Lens. 2018; 44 (October 20): 159-163
        • Romero-Jiménez M.
        • Flores-Rodríguez P.
        Utility of a semi-scleral contact lens design in the management of the irregular cornea.
        Cont Lens Anterior Eye. 2013; 36: 146-150
        • Visser E.S.
        • Van Der Linden B.J.J.J.
        • Otten H.M.
        • Van Der Lelij A.
        • Visser R.
        Medical applications and outcomes of bitangential scleral lenses.
        Optom Vis Sci. 2013; 90: 1078-1085
        • Montalt J.C.
        • Porcar E.
        • España-Gregori E.
        • Peris-Martínez C.
        Visual quality with corneo-scleral contact lenses for keratoconus management.
        Cont Lens Anterior Eye. 2018; : 0-1
        • Otten H.M.
        • van der Linden B.J.J.J.
        • Visser E.
        Clinical performance of a new bitangential mini-scleral lens.
        Optom Vis Sci. 2018; 95: 515-522
        • Dimit R.
        • Gire A.
        • Pflugfelder S.C.
        • Bergmanson J.P.G.
        Patient ocular conditions and clinical outcomes using a PROSE scleral device.
        Cont Lens Anterior Eye. 2013; 36: 159-163
        • Lee J.C.
        • Chiu G.B.
        • Bach D.
        • Bababeygy S.R.
        • Irvine J.
        • Heur M.
        Functional and visual improvement with prosthetic replacement of the ocular surface ecosystem scleral lenses for irregular corneas.
        Cornea. 2013; 32: 1540-1543
        • Baran I.
        • Bradley J.A.
        • Alipour F.
        • Rosenthal P.
        • Le H.G.
        • Jacobs D.S.
        PROSE treatment of corneal ectasia.
        Cont Lens Anterior Eye. 2012; 35: 222-227
        • Arumugam A.O.
        • Rajan R.
        • Subramanian M.
        • Mahadevan R.
        PROSE for irregular corneas at a tertiary eye care center.
        Eye Contact Lens. 2014; 40: 71-73
        • Pecego M.
        • Barnett M.
        • Mannis M.J.
        • Durbin-Johnson B.
        Jupiter scleral lenses: The UC Davis Eye Center experience.
        Eye Contact Lens. 2012; 38: 179-182
        • Ortenberg I.
        • Behrman S.
        • Geraisy W.
        • Barequet I.S.
        Wearing time as a measure of success of scleral lenses for patients with irregular astigmatism.
        Eye Contact Lens. 2013; 39: 381-384
        • Suarez C.
        • Madariaga V.
        • Lepage B.
        • Malecaze M.
        • Fournié P.
        • Soler V.
        • et al.
        First experience with the ICD 16.5 mini-scleral Lens for optic and therapeutic purposes.
        Eye Contact Lens. 2016; 0: 1
        • Mahmoud A.M.
        • Roberts C.J.
        • Lembach R.G.
        • Twa M.D.
        • Herderick E.E.
        • McMahon T.T.
        CLMI: the cone location and magnitude index.
        Cornea. 2008; 27: 480-487
        • McMahon T.T.
        • Anderson R.J.
        • Joslin C.E.
        • Rosas G.A.
        • Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study Topography Analysis Group
        Precision of three topography instruments in keratoconus subjects.
        Optom Vis Sci. 2001; 78: 599-604
        • Kocamış S.İ
        • Çakmak H.B.
        • Çağıl N.
        • Toklu Y.
        Investigation of the efficacy of the cone location and magnitude index in the diagnosis of keratoconus.
        Semin Ophthalmol. 2014; 31: 1-7
        • Mandell R.B.
        Slit lamp classification system.
        J Am Optom Assoc. 1987; 58: 198-201
        • Alió J.L.
        • Shabayek M.H.
        Corneal higher order aberrations: a method to grade keratoconus.
        J Refract Surg. 2006; 22: 539-545
        • Visser E.-S.
        • Visser R.
        • van Lier H.J.J.
        • Otten H.M.
        Modern scleral lenses part II: patient satisfaction.
        Eye Contact Lens. 2007; 33: 21-25
        • Schornack M.M.
        • Patel S.V.
        Relationship between corneal topographic indices and scleral lens base curve.
        Eye Contact Lens. 2010; 36: 330-333
        • Sorbara L.
        • Maram J.
        • Mueller K.
        Use of the VisanteTM OCT to measure the sagittal depth and scleral shape of keratoconus compared to normal corneae: pilot study.
        J Optom. 2013; 6: 141-146
        • Downie L.E.
        Predictive value of corneal topography for ClearKone hybrid contact lenses.
        Optom Vis Sci. 2013; 90: 191-197