Researchers in Greece have determined that patients with glaucoma have reduced and irregular corneal epithelial thickness even if they do not report symptoms of dry eyes. This small but statistically significant reduction uniformly affected all regions of the cornea.

The study anterior segment OCT to assess 62 patients with primary open angle or pseudoexfoliative glaucoma as well as 62 controls. Τhe team used the pachymetry scan pattern to map the cornea and recorded the software generated corneal thickness parameters. The researchers assessed comparisons between groups and the correlations of epithelial thickness parameters with parameters associated with medication use. The median number of instillations of medication was two (range: one to six) for the glaucoma group. 

The central corneal thickness was 537.6µm in the glaucoma group and 550.8µm in the control group respectively. The central corneal epithelial thickness was 48.8μm in the glaucoma group and 53.5μm in the control group. Surprisingly the magnitude of the reduction in epithelial thickness was almost equal the superior and the inferior zones (45μm vs. 49.6μm and 49μm vs. 53.5µm, respectively). No corneal epithelial thickness parameter was correlated with any of the treatment parameters.

“To our understanding, these findings may indicate an increased irregularity of corneal epithelium in the glaucoma population,” the researchers wrote in the paper. They noted that that it is similar to the irregularity observed in dry eye patients.

Halkiadakis I, Vernikou A, Tzimis V, et al. Assessment of corneal epithelium thickness in glaucomatous patients undergoing medical treatment. J Glaucoma. September 22, 2020. [Epub ahead of print].