Central corneal thickness and glaucoma treatment: an Italian multicenter cross-sectional study

Supposedly, prostaglandin analogs (PGA) could reduce the central corneal thickness (CCT), while topical carbonic anhydrase inhibitors (TCAI) could increase CCT. The aim of the study was to evaluate clinically significant CCT effects in patients treated with PGA or TCAI.

At least 50 glaucomatous patients were saved on the Italian Glaucoma Register from 16 different glaucoma centers. About 816 glaucomatous patients were found in the register; of these, 316 were recruited in this study because they were treated with PGA or TCAI. The diagnosis of glaucoma was based on visual field examination, optic nerve head analysis, intraocular pressure (IOP) measurements, and gonioscopy. Two age-matched subgroups were created: one treated with PGA and the other with TCAI. CCT, ophthalmoscopic cup/disc ratio (CDR), mean deviation (MD), pattern standard deviation (PSD), and IOP were considered for both eyes of each patient. Student t-test was used to compare the 2 subgroups.

The mean age of the PGA group was 66.35±12.17 years, while 65.17±12.52 years was for the TCAI group. No significant difference was found for CCT (543.75±35 μm and 544±35 μm, respectively), CDR (0.55±0.2 and 0.53±0.2, respectively), MD (-4.5±4.9 dB and -5.4±6.4 dB, respectively), PSD (4.6±3.4 and 4.6±4.9, respectively), and IOP (15.9±3.3 mmHg and 15.7±2.9 mmHg, respectively) between the 2 subgroups. A significant (P<0.001) correlation was found between CCT and CDR and between CCT and IOP.

No significant difference in CCT was found between patients treated with PGA and TCAI, suggesting that these topical medications did not statistically and clinically change the CCT.