Conjunctival and corneal sensitivity in patients under topical antiglaucoma treatment

The purpose of the study is to measure corneal and conjunctival sensitivity in patients under glaucoma topical treatment as compared to a control group. It is a case-control study. Corneal and conjunctival esthesiometry were carried out through a Cochet-Bonnet esthesiometer. We took healthy individuals as controls, who did not use any type of ophthalmic topical medications and without history of ocular surface pathology or irritation. The study group was subdivided per number of applications (1, 2, and 3 or more applications). From a total 182 eyes from 91 patients, of which 26 (28.57 %) were controls and 65 (71.43 %) were in the study group, a mean corneal sensitivity of 58.98 ± 2.25 mm was found in the control group and 52.97 ± 6.41 mm in patients using topical medication. Mean conjunctival sensitivity was 18.80 ± 5.40 mm in the control group and 11.76 ± 5.45 mm in the study group. There was no statistically significant difference among groups when separated by 1, 2, and 3 or more applications. Eyes under use of timolol-containing medications showed lower sensitivity values as compared to other topical antiglaucoma medications. Corneal and conjunctival sensitivities are diminished in patients with chronic use of topical hypotensive medications and these results can explain the lack of correlation between signs and symptoms that is typically found in patients treated for glaucoma or ocular hypertension.