EFFECTS OF THE CONTACT LENS INDUCED SWELLING ON ANTERIOR AND POSTERIOR CORNEAL SURFACES.

Amir Moezzi

Abstract

PURPOSE. To examine the Best Fit Sphere data of both anterior and posterior corneal surfaces in response to contact lens induced swelling. METHOD. An OrbscanII Corneal Topographer was used to measure corneal swelling and the anterior and posterior corneal surfaces of 17 neophytes before and after wearing soft and PMMA Contact lenses. The lens-wearing eye was patched for three hours.

RESULTS. Central corneal swelling induced by lens wear and eye closure was 14.9%±3.8% and 12.7%±4% for soft and PMMA lenses respectively (Mean±S.D. for all results quoted). The anterior Best Fit Sphere radius remained unchanged in response to soft lenses [0.00±0.04, p=0.899(paired t-test)] and steepened slightly but significantly with PMMA (0.04±0.05mm, p=0.003). The posterior Best Fit Sphere radius showed flattening for all 17 subjects of 0.12±0.07mm (p=0.000) with soft and 0.14±0.08mm (p=0.000) with PMMA lenses.

CONCLUSIONS. From the Best Fit Sphere data, we can conclude that contact lens induced corneal swelling did not have a significant effect on the anterior surface from the soft lens but a very slight steepening effect with the PMMA lens. On the other hand, the posterior surface appeared to flatten with both lenses which is consistent with the theory of corneal swelling.

Details

Year: 2001

Program Number: Poster 128

Author Affiliation: University of Waterloo, School of Optometry

Co-Authors: Desmond Fonn, Luigina Sorbara, Trefford Simpson

Co-Author Affiliation: University of Waterloo, School of Optometry, University of Waterloo, School of Optometry, University of Waterloo, School of Optometry

Room: Exhibit Hall C