Effects of topical antiglaucomatous medications on central corneal epithelial thickness by anterior segment optical coherence tomography

Abstract

Purpose: To evaluate the effect of topical antiglaucomatous medications on central corneal epithelial thickness measured by anterior segment optical coherence tomography. Materials and methods: A total of 153 eyes of 153 patients using topical antiglaucomatous medications and 110 eyes of 110 control subjects were enrolled. Glaucoma type, duration of therapy, the number of drugs, and drops/day were noted in the patient group. Patients and control subjects underwent ocular examinations including Schirmer test, slit lamp examination for tear film break-up time, and anterior segment optical coherence tomography for central corneal thickness and central corneal epithelial thickness. Central corneal epithelial thickness and other data were evaluated separately with regard to glaucoma type, duration of therapy, the number of drops, and drugs in the patient group. Results: The mean ages of the patients and controls were 60.1 ± 10.8 and 58.7 ± 11.2 years, respectively. The groups were similar with regard to mean age and gender (p = 0.058, p = 0.734, respectively). The median (interquartile range) central corneal thickness was 536 (54) µm in patients and 552 (53) µm in controls (p = 0.011). The median (interquartile range) central corneal epithelial thickness of patients and controls were 56 (4) µm and 60 (8) µm, respectively (p < 0.001). The median (interquartile range) tear film break-up time and Schirmer were 12 (6) s and 10 (8) mm in patients and 16 (2) s and 18 (4) mm in controls, respectively (p < 0.001, p < 0.001). In patient group, there was no significant difference in the median central corneal thickness, central corneal epithelial thickness, and tear film break-up time in terms of glaucoma type, duration of therapy, the number of drugs, and the number of daily drops. Only the median Schirmer test was found to be statistically lower in terms of number of daily eye drops (p = 0.039). Conclusion: Using topical antiglaucomatous medications seems to affect the central corneal epithelial thickness in glaucoma patients. Central corneal epithelial thickness was thinner in glaucoma patients than controls. Anterior segment optical coherence tomography might be helpful to evaluate the effect of antiglaucomatous medications on central corneal epithelial thickness during treatment.

Changes in Corneal Epithelial Thickness Induced by Topical Antiglaucoma Medications

“…Given the increased prevalence of dry eye or ocular surface discomfort in patients with glaucoma, previous studies investigated the effects of IOP-lowering eyedrops on CET and reported smaller CETs in patients with glaucoma [17][18][19]. Since commercially available antiglaucoma eyedrops often contain preservatives, many concerns have been raised regarding the effect of these preservatives on ocular surface health.…”

“…When compared to an age-matched control group without glaucoma, the glaucoma group showed statistically significant reduction in CET in all 25 sectors over a 9.0 mm diameter area. Previous studies have reported reduced CETs in patients with glaucoma, but only few studies revealed significant factors affecting the reduction in CET [17][18][19]. Many studies used manual measurements of the central cornea and examined a relatively small number of subjects.…”

“…Since patients with glaucoma often require the long-term use of multiple eyedrops, the possible adverse effects of these drugs on the ocular surface have been important topics of research [14][15][16]. Previous studies that investigated the effects of glaucoma eyedrops on CET reported that patients with glaucoma had uniformly reduced CETs compared to normal controls [17][18][19]. Most studies, however, failed to detect any association between CET and treatment parameters.…”

Confocal Microscopy and Anterior Segment Optical Coherence Tomography Imaging of the Ocular Surface and Bleb Morphology in Medically and Surgically Treated Glaucoma Patients: A Review

“…Differently, a recent study did not find significant differences in corneal epithelial thickness among patients under different types and durations of treatment, while the only factor influencing corneal epithelial thickness was represented by age [ 77 ]. In a similar study, Dogan et al [ 78 ] reported that there was no significant correlation between corneal thickness and glaucoma type, duration of therapy, number of drugs, and daily drops.…”

“…Discording results in the corneal thickness parameters at AS-OCT o with regard to the number of drugs used [ 76 , 77 , 78 ]…”