Materials and Methods: A total 82 eyes of 59 patients were included into this retrospective study. The glaucoma patients and glaucoma-suspected individuals, who had the values of corneal thickness measured by anterior segment optical coherence tomography (AS-OCT) in their medical records, were assigned to three groups. Group 1 involved the glaucoma patients who were receiving only one anti-glaucoma eye drop which contains either only one of the three PGAs (latanoprost 0.005%, travoprost 0.004%, or bimatoprost 0.03%), or a combination of one of those with timolol. Group 2 involved the glaucoma patients who were receiving more than one anti-glaucoma eye drop, provided that one of them should contain any of the PGAs. Group 3 involved the glaucoma-suspected individuals who were not receiving any anti-glaucoma eye drop.

Results: The mean thickness of the corneal epithelium was significantly thinner in Group 1 and Group 2 [(56±3.1 ?m in Group 1 vs. 61.2±2.1 ?m in Group 3, p<0.001), (56.3±2.8 ?m in Group 2 vs. 61.2±2.1 ?m in Group 3, p<0.001)]. On the other hand, the mean thickness of corneal stroma was only significantly thinner in Group 2 [(448±40 ?m in Group 2 vs.496±40 ?m in Group 3, p<0.001), (448±40 ?m in Group 2 vs. 486±30 ?m in Group 1, p=0.001)].

Conclusions: The PGAs can reduce corneal epithelial thickness when they are used in one eye drop, or in combination with the other anti-glaucoma eye drops. However, corneal stromal thinning may appear in case of PGAs are used in combination with other anti-glaucoma eye drops. Keywords : AS-OCT; corneal epithelium; corneal stroma; prostaglandin analogues