Overnight corneal swelling in symptomatic and asymptomatic contact lens wearers

High corneal swelling with contact lens wear may be a predictor of patient failure in overnight contact lens use. This study evaluated whether contact lens wearers who had previously experienced corneal inflammation showed greater corneal swelling following a single occasion of overnight contact lens use compared with matched controls.

Forty-four subjects were evaluated: 9 wearers who had experienced contact lens associated acute red eye (CLARE); 9 controls; 13 subjects who had experienced contact lens induced peripheral ulcer (CLPU); and 13 controls. Controls were matched to cases for age, gender, wear experience and refractive error. Subjects wore bilateral disposable contact lenses overnight. Central corneal thickness was measured optically using a Holden-Payor pachometer at baseline, on eye opening, and 1, 2, and 4 hours later.

There was no significant difference in overnight corneal swelling between CLARE subjects (7.6 +/- 2.3%) and controls (7.0 +/- 2.3%) (P = 0.57). Similarly, there was no significant difference in overnight corneal swelling between CLPU subjects (7.7 +/- 2.2%) and controls (7.8 +/- 2.6%) (P = 0.89). Deswell rate was similar in all groups.

There was no apparent predisposition for higher overnight corneal swelling or altered deswell rate after one night of lens wear in subjects who had previously experienced contact lens related corneal inflammation.