Contact Lens & Anterior Eye
Volume 31, Issue 2 , Pages 89-94 , April 2008

The effect of lens wear on refractive index of conventional hydrogel and silicone-hydrogel contact lenses: A comparative study

  • M. Lira

      Affiliations

    • Center of Physics (Optometry), School of Sciences, University of Minho, Portugal
    • Corresponding Author InformationCorresponding author at: Department of Physics, University of Minho, Campus of Gualtar, Braga, Portugal. Tel.: +351 253604068; fax: +351 253678981.
    • ,
  • L. Santos

      Affiliations

    • IBB—Institute for Biotechnology and Bioengineering, Center of Biological Engineering, University of Minho, Portugal
    • ,
  • J. Azeredo

      Affiliations

    • IBB—Institute for Biotechnology and Bioengineering, Center of Biological Engineering, University of Minho, Portugal
    • ,
  • E. Yebra-Pimentel

      Affiliations

    • School of Optics and Optometry, University of Santiago de Compostela, Spain
    • ,
  • M.E.C.D. Real Oliveira

      Affiliations

    • Center of Physics (Optometry), School of Sciences, University of Minho, Portugal

References 

  1. Nicolson PC, Vogt J. Soft contact lens polymers: an evolution. Biomaterials. 2001;22:3273–3283
  2. Tighe B. In:  Sweeney D editors. Silicone hydrogels: the rebirth of continuous wear. Oxford: Butterworth-Heinemann; 2000;p. 1–21
  3. Nichols JJ, Berntsen DA. The assessment of automated measures of hydrogel contact lens refractive index. Ophthal Physiol Opt. 2003;23:517–525
  4. Andrasko G, Schoessler JP. The effect of humidity on dehydration of soft contact lens on the eye. ICLC. 1980;7:210–213
  5. Lowther GE. Lens dehydration: what are the problems and the management?. ICLC. 1983;10:7
  6. Paugh JR. Equivalent oxygen percentage as a function of hydration in hydrogel lenses: an in vivo study. Optom Vis Sci. 1992;69:805–810
  7. Brennan NA, Efron N, Bruce AS, Duldig DI, Russo NJ. Dehydration of hydrogel lenses: environmental influences during normal wear. Am J Optom Physiol Opt. 1988;65:277–281
  8. Morgan PB, Efron N, Morgan SL, Little SA. Hydrogel contact lens dehydration in controlled environmental conditions. Eye Cont Lens. 2004;30:99–102
  9. Cabrera JV, Velasco MJ. Recovery of the water content of hydrogel contact lenses after use. Ophthal Physiol Opt. 2005;25:452–457
  10. Pritchard N, Fonn D, Brazeau D. Discontinuation of contact lens wear: a survey. Int Cont Lens Clin. 1999;26:157–162
  11. Young G, Veys J, Pritchard N, Coleman S. A multi-centre study of lapsed contact lens wearers. Ophthal Physiol Opt. 2002;22:516–527
  12. Efron N, Brennan NA, Bruce AS, Duldig DI, Russo NJ. Dehydration of hydrogel lenses under normal wearing conditions. CLAO J. 1987;13:152–156
  13. Pritchard N, Fonn D. Dehydration, lens movement and dryness ratings of hydrogel contact lenses. Ophthal Physiol Opt. 1995;15:281–286
  14. Nichols JJ, Sinnott LT. Tear film, contact lens, and patient-related factors associated with contact lens-related dry eye. Invest Ophthal Vis Sci. 2006;47:1319–1328
  15. Andrasko G. Hydrogel dehydration in various environments. ICLC. 1983;10:23–28
  16. Nason RJ, Boshnick EL, Cannon WM. Multisite comparison of contact lens modalities. Daily disposable wear vs. conventional daily wear in successful contact lens wearers. J Am Optom Assoc. 1994;65:774–780
  17. Boswall GJ, Ehlers WH, Luistro A, Worrall M, Donshik PC. A comparison of conventional and disposable extended wear contact lenses. CLAO J. 1993;19:158–165
  18. Cheng L, Muller SJ, Radke CJ. Wettability of silicone-hydrogel contact lenses in the presence of tear-film components. Curr Eye Res. 2004;28:93–108
  19. Jones L, Franklin V, Evans K, Sariri R, Tighe B. Spoilation and clinical performance of monthly vs. three monthly Group II disposable contact lenses. Optom Vis Sci. 1996;73:16–21
  20. Fonn D, Pritchard N, Dumbleton K. In:  Sweeney D editors. Silicone hydrogels: the rebirth of continuous wear contact lenses. Oxford, UK: Butterwrth-Heinemann; 2000;p. 214–234
  21. Tighe B. Silicone hydrogels: what are they and how should they be used in everyday practice?. Optician. 1999;31–32
  22. Jones L, Senchyna M, Glasier MA, Schickler J, Forbes I, Louie D, et al. Lysozyme and lipid deposition on silicone hydrogel contact lens materials. Eye Con Lens. 2003;29:S75–S79
  23. Moradi O, Modarress H, Noroozi M. Experimental study of albumin and lysozyme adsorption onto acrylic acid (AA) and 2-hydroxyethyl methacrylate (HEMA) surfaces. J Colloid Interface Sci. 2004;271:16–19
  24. Bruinsma GM, van der Mei HC, Busscher HJ. Bacterial adhesion to surface hydrophilic and hydrophobic contact lenses. Biomaterials. 2001;22:3217–3224
  25. Henriques M, Sousa C, Lira M, Real Oliveira MECD, Oliveira R, Azeredo J. Adhesion of Pseudomonas aeruginosa and Staphylococcus epidermidis to silicone-hydrogel contact lenses. Optom Vis Sci. 2005;82:446–450
  26. Lopez-Alemany A, Compan V, Refojo MF. Porous structure of Purevision versus Focus Night&Day and conventional hydrogel contact lenses. J Biomed Mater Res. 2002;63:319–325
  27. Brennan NA. A simple instrument for measuring the water content of hydrogel lenses. ICLC. 1983;357–361
  28. Mousa GY, Calander MG, Sivak JG, Egan DJ. The effect of the hydration characteristics of hydrogel lenses on the refractive index. ICLC. 1983;31–37
  29. Gonzalez-Meijome JM, Lira M, Lopez-Alemany A, Almeida JB, Parafita MA, Refojo MF. Refractive index and equilibrium water content of conventional and silicone hydrogel contact lenses. Ophthal Physiol Opt. 2006;26:57–64
  30. Gonzalez-Meijome JM, Lopez-Alemany A, Lira M, Almeida JB, Real Oliveira MECD, Parafita MA. Equivalences between refractive index and equilibrium water content of conventional and silicone hydrogel soft contact lenses from automated and manual refractometry. J Biomed Mater Res B Appl Biomater. 2007;80:184–191
  31. Brennan NA, Efron N, Truong VT, Watkins RD. Definitions for hydration changes of hydrogel lenses. Ophthal Physiol Opt. 1986;6:333–338
  32. Alemany AL, Refojo MF. Comparative study of the hydration of hydrophilic contact lenses by refractive index and gravimetry. CLAO J. 2000;26:200–203
  33. Morgan PB, Efron N. In vivo dehydration of silicone hydrogel contact lenses. Eye Cont Lens. 2003;29:173–176
  34. Nichols JJ, Mitchell GL, Good GW. The reliability and validity of hand-held refractometry water content measures of hydrogel lenses. Optom Vis Sci. 2003;80:447–453
  35. Brennan NA, Lowe R, Efron N, Harris MG. In vivo dehydration of disposable (Acuvue) contact lenses. Optom Vis Sci. 1990;67:201–203
  36. Fonn D, Situ P, Simpson T. Hydrogel lens dehydration and subjective comfort and dryness ratings in symptomatic and asymptomatic contact lens wearers. Optom Vis Sci. 1999;76:700–704
  37. Kohler JE, Flanagan GW. Clinical dehydration of extended wear lenses. Int Cont Lens Clin. 1985;152–161
  38. Tranoudis I, Efron N. Water properties of soft contact lens materials. Cont Lens Anterior Eye. 2004;27:193–208
  39. Efron N, Morgan PB. Hydrogel contact lens dehydration and oxygen transmissibility. CLAO J. 1999;25:148–151
  40. Fornasiero F, Prausnitz JM, Radke CJ. Post-lens tear film depletion due to evaporative dehydration of a soft lens. J Membr Sci. 2006;229–243
  41. Jones L, May C, Nazar L, Simpson T. In vitro evaluation of the dehydration characteristics of silicone hydrogel and conventional hydrogel contact lens materials. Cont Lens Anterior Eye. 2002;25:147–156
  42. Hall B, Jones S, Young G, Coleman S. The on-eye dehydration of proclear compatibles lenses. CLAO J. 1999;25:233–237
  43. Tranoudis I, Efron N. Parameter stability of soft contact lenses made from different materials. Cont Lens Anterior Eye. 2004;27:115–131
  44. Lebow K, Bridgewater B. A three-month comparative daily-wear study of two high water content soft lenses. ICLC. 1997;198–205
  45. Morgan PB, Efron N. Hydrogel contact lens ageing. CLAO J. 2000;26:85–90
  46. Santos L, Rodrigues D, Lira M, Real Oliveira MECD, Oliveira R, Azeredo J. The influence of surface treatment on hydrophobicity, protein adsorption and microbial colonisation of silicone hydrogel contact lenses. Cont Lens Anterior Eye. 2007;30:183–188

PII: S1367-0484(07)00102-6

doi: 10.1016/j.clae.2007.09.001

Contact Lens & Anterior Eye
Volume 31, Issue 2 , Pages 89-94 , April 2008

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