Effect of Acute Increases of Intraocular Pressure on Corneal Pachymetry in Eyes Treated with Travoprost: An Animal Study

Abstract

Purpose: To evaluate "in vivo" the effect of topical travoprost on the central corneal thickness (CCT) of rabbit eyes, and the changes in the CCT after acute increases of intraocular pressure (IOP) in these eyes. Materials and Methods: This is an interventional, prospective, case-control, masked study. Topical travoprost was applied once daily for one month to the right eye of six New Zealand male rabbits, the left eye of each animal served as control. The baseline CCT and IOP were measured under general anesthesia. After the IOP was stabilized at 15 and 30 mmHg, as registered by direct cannulation of the anterior chamber, CCT measurements were measured again at both pressure levels. Results: The baseline CCT was thicker in eyes previously treated with travoprost (study group) than in control eyes (p < 0.01). The CCT decreased in both groups when IOP was raised to 15 and 30 mmHg, and there were no statistically significant difference in absolute CCT values between study and control eyes at any of the IOP levels (p == 0.5). However, the amount of CCT decrease from baseline values was greater in eyes previously treated with travoprost (study group) than in control ones, at both 15 and 30 mmHg IOP levels (p == 0.01 and 0.02, respectively). Conclusions: Rabbit corneas treated with topical travoprost show a different strain response to acute increases in IOP than control eyes.