Lens parameter changes under in vitro and ex vivo conditions and their effect on the conjunctiva |
| |
| Affiliation: | 1. Brien Holden Vision Institute, Sydney, Australia;2. School of Optometry and Vision Science, University of New South Wales, Sydney, Australia;3. Alcon Laboratories, Fort Worth, USA;1. Health Sciences University Samsun Training and Research Hospital, Department of Ophthalmology Samsun, Turkey;2. Department of Ophthalmology, Van Yuzuncu Yil University, Faculty Of Medicine, Turkey;1. Department of Ophthalmology and Visual Sciences, Paulista School of Medicine, Federal University of Sao Paulo (EPM-UNIFESP), Sao Paulo, Brazil;2. Ocular Cell Biology Group, Center for Applied Biotechnology and Molecular Medicine, University of Zurich (UZH), Zurich, Switzerland |
| |
| Abstract: | PurposeTo quantify changes in contact lens parameters induced by lens wear and determine whether these changes are associated with contact lens-induced conjunctival staining (CLICS).MethodsIn vitro: Lens diameter, sag, edge shape, base curve of six contact lens brands (balafilcon, comfilcon, etafilcon, lotrafilcon B, omafilcon and senofilcon) measured at 21 °C and 35 °C (eye temperature). Ex vivo: Diameter of lenses collected from a prospective, randomised, contra-lateral, cross-over clinical trial from 36 subjects wearing all lens types for 1 week daily wear, measured in 35 °C PBS after removal. Ocular surface was examined for lens-induced conjunctival staining by masked examiner.ResultsIn vitro: Changes in diameter and base curve outside ISO tolerance were found with etafilcon A and omafilcon A. Ex vivo: Comfilcon A and etafilcon A had greatest shrinkage in diameter (0.18 mm) and base curve (0.11 mm steeper) with temperature increase from 21 °C to 35 °C. Senofilcon A, lotrafilcon B and balafilcon A maintained most stable parameters between 21 °C and 35 °C. Changes in diameter and base curve from lens wear were not correlated with CLICS (p > 0.49). Multivariate analysis showed significantly greater levels of lens induced staining were associated with lens modulus (p < 0.001) and knife (p < 0.001) and chisel (p < 0.001) edge shapes.ConclusionsParameter changes induced by lens wear were associated with increasing temperature, but these changes in lens diameter and base curve did not induce CLICS. Modulus and edge shape were associated with increased CLICS. The susceptibility of etafilcon A and omafilcon A lenses to parameter changes might be related to their high water content. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
