Changes in corneal parameters at Confocal Microscopy in glaucoma patients may due to medical treatment

Purpose:To evaluate the corneal parameters with confocal microscopy in treated glaucoma patients, non-treated glaucoma patients and normal subjects. Methods:40 consecutive patients with primary open-angle glaucoma and 22 age and sex-matched untreated controls underwent confocal microscopy of the cornea using HRT II (Heidelberg Retinal Tomograph) cornea module. Glaucoma group was divided into two subgroups: patients with medical treatment for at least two years before inclusion (with beta-blockers or prostaglandin analogues) and non-treated glaucoma patients. The following corneal parameters were evaluated: endothelial cell density; number, reflectivity and tortuosity of subbasal nerves. For reflectivity and tortuosity a dedicated grading scales ranging from 0 to 4 were used (Oliveira-Soto, Cornea. 2001). Mean values were compared by means of two-tailed t-test for unpaired data; in the treated glaucoma group, differences between treatments were also evaluated. Results:The results are summarized in the Table Conclusions:Treated glaucoma patients show lower endothelial density, lower nerve density and reflectivity and higher tortuosity when compared to controls and untreated patients; no significant difference was found between untreated glaucoma patients and normal subjects. As shown previously, (Ranno, ARVO 2008), non statistically significant difference was found between prostaglandin-analogue and beta-blockers in treated glaucoma patients. This study shows that differences in corneal parameters between glaucoma patients and controls may be due to the medical treatments of glaucoma. These data should be taken into consideration in long-standing medical glaucoma treatment and in candidate for surgery.