Equivalences between refractive index and equilibrium water content of conventional and silicone hydrogel contact lenses from automated and manual refractometry

Journal of Biomedical Materials Research - Part B Applied Biomaterials

Volumn 80, Issue 1, 2007, Pages 184-191

  González Méijome, José M ^a   López Alemany, Antonio ^b,c   Lira, Madalena ^a   Almeida, José B ^a   Real Oliveira, M Elisabete C D ^a   Parafita, Manuel A ^d  

^a UNIVERSITY OF MINHO   (Portugal)

^b UNIVERSITY OF VALENCIA   (Spain)

^c Institute of Ophthalmology and Optometry of La Costera (IOOC)   (Spain)

^d UNIVERSITY OF SANTIAGO DE COMPOSTELA   (Spain)

Author keywords

Atago N 2E; Brix scale; CLR 12 70; Conventional soft contact lenses; Equilibrium water content; Refractive index; Refractometry; Silicone hydrogel; Sucrose

Indexed keywords

DEHYDRATION; HYDROGELS; REFRACTIVE INDEX; REFRACTOMETERS; SUGAR (SUCROSE);

ATAGO N-2E; BRIX SCALES; CONVENTIONAL SOFT CONTACT LENSES; EQUILIBRIUM WATER CONTENT; REFRACTOMETRY; SILICONE HYDROGELS;

CONTACT LENSES;

SILICON DERIVATIVE; SUCROSE;

ARTICLE; AUTOMATION; COMPARATIVE STUDY; CORRELATION ANALYSIS; HYDRATION; HYDROGEL; INTERMETHOD COMPARISON; LINEAR SYSTEM; MATHEMATICAL MODEL; MEASUREMENT; MODEL; REFRACTION INDEX; REFRACTOMETER; REFRACTOMETRY; SOFT CONTACT LENS; STATISTICAL SIGNIFICANCE; WATER CONTENT;

BIOCOMPATIBLE MATERIALS; CONTACT LENSES, HYDROPHILIC; HUMANS; HYDROGELS; REFRACTOMETRY; SILICONES; WATER;

EID: 33845917851     PISSN: 00219304     EISSN: 15524981     Source Type: Journal    
DOI: 10.1002/jbm.b.30583     Document Type: Article

References (28)

1. Brennan NA. A simple instrument for measuring the water content of hydrogel lenses. Int Contact Lens Clin 1983;10:357-361.
2. Mousa GY, Callender MG, Sivak JG, Edan DJ. The effect of index hydratation caracteristics of hydrogel lenses on the refractive index. Int Contact Lens Clin 1983;10:31-37.
3. Morgan PB, Efron N. Hydrogel contact lens ageing. CLAO J 2000;26:85-90.
4. Brennan NA, Lowe R, Efron N, Harris MG. In vivo dehydration of disposable (Acuvue) contact lenses. Optom Vis Sci 1990;67:201-203.
5. Quesnel NM, Giasson CJ. On-eye dehydration of Proclear, Resolution 55G and Acuvue contact lenses. Contact Lens Anterior Eye 2001;24:88-93.
6. Orsborn GN, Zantos SG. Corneal desiccation staining with thin high water content contact lenses. CLAO J 1988;14:81-85.
7. Gispcts J, Varon C. The influence of water content of hydrogel contact lenses when fitting patients with tear film deficiency. Contact Lens Anterior Eye 2000;23:16-21.
8. Little SA, Bruce AS. Role of the post-lens tear film in the mechanism of inferior arcuate staining with ultrathin hydrogel lenses. CLAO J 1995;21:175-181.
9. 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.
10. Young G, Bowers R, Hall B, Port M. Clinical comparison of Omafilcon A with four control materials. CLAO J 1997;23:249-258.
11. Morgan PB, Efron N, Morgan SL, Little SA. Hydrogel contact lens dehydration in controlled environmental conditions. Eye Contact Lens 2004;30:99-102.
12. Efron N, Golding TR, Brennan NA. The effect of soft lens lubricants on symptoms and lens dehydration. CLAO J 1991;17:114-119.
13. Pritchard N, Fonn D. Dehydration, lens movement and dryness ratings of hydrogel contact lenses. Ophthalmic Physiol Opt 1995;15:281-286.
14. Young G, Veys J, Pritchard N, Coleman S. A multi-centre study of lapsed contact lens wearers. Ophthalmic Physiol Opt 2002;22:516-527.
15. Schlanger JL. A study of contact lens failures. J Am Optom Assoc 1993;64:220-224.
16. Pritchard N, Fonn D, Brazeau D. Discontinuation of contact lens wear: A survey. Int Contact Lens Clin 1999;26:157-162.
17. Alemany AL, Refojo MF. Comparative study of the hydration of hydrophilic contact lenses by refractive index and gravimetry. CLAO J 2000;26:200-203.
18. Galas SL, Enns JB. Humidity-conditioned gravimetric method to measure the water content of hydrogel contact lens materials. Optom Vis Sci 1993;70:577-586.
19. Morgan PB, Efron N. In vivo dehydration of silicone hydrogel contact lenses. Eye Contact Lens 2003;29:173-176.
20. Hermans PH. Gels. In: Kruyt, editor. Colloid Science. New York: Elsevier; 1949. pp 482-651.
21. Young MD, Benjamin WJ. Calibrated oxygen permeability of 35 conventional hydrogel materials and correlation with water content. Eye Contact Lens 2003;29:126-133.
22. Fatt I. Comparative study of some physiologically important properties of six brands of disposable hydrogel contact lenses. CLAO J 1997;23:49-54.
23. 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.
24. Tranoudis I, Efron N. Refractive index of rigid contact lens materials. Contact Lens Anterior Eye 1998;21:15-18.
25. Nichols JJ, Berntsen DA. The assessment of automated measures of hydrogel contact lens refractive index. Ophthalmic Physiol Opt 2003;23:517-525.
26. Fatt I, Chaston J. The effect of temperature on refractive index, water content and central thickness of hydrogel contact lenses. Int Contact Lens Clin 1980;7:37-41.
27. Gonzalez-Meijome JM, Lopez-Alemany A, Parafita MA. Practical concerns on the measuring of soft contact lens hydration with hand-held refractometry. Revista Española de Contactologia. 2005;12:27-35.
28. Gonzalez-Meijome JM, Lira M, Lopez-Alemany A, Almeida JB, Parafita M, Refojo MF. Refractive index and equilibrium water content of conventional and silicone hydrogel contact lenses. Ophthalmic Physiol Opt 2006;25:57-64.