Effect of the Rigid Gas-Permeable Contact Lens Use on the Endothelial Cells in Patients With Keratoconus

OBJECTIVES: To compare the changes in the corneal endothelial cells of both the patients with keratoconus who use rigid gas-permeable (RGP) contact lens and who do not use any contact lens with healthy population. METHODS: Thirty-three patients with keratoconus who use RGP contact lenses (group 1), 20 patients with keratoconus who do not use any contact lens (group 2), and 40 healthy controls were included in the study. Changes in the corneal endothelial cells of all patients were evaluated using a noncontact specular microscope. Endothelial cell density (ECD), coefficient of variability (CV), hexagonal cell percentage (%HEX), and central corneal thickness (CCT) of the patients were evaluated in the study. RESULTS: In the groups 1, 2, and 3, the mean ECD was 2,420.8±247, 2,579.5±240, and 2,589.5±271 cells/mm, the mean CV was 357±9, 34±7, and 34±6, the mean %HEX was 54.3±13, 59.1±14, and 57.4±10, and the mean CCT was 508±33, 504±43, and 561±34 μm, respectively. There was no significant difference between the groups in terms of ECD, CV, and %HEX. Although significant differences between the groups 1 to 3 and groups 2 to 3 in terms of CCT were detected (P=0.001 and P=0.004, respectively), no significant difference was observed between the groups 1 and 2. CONCLUSIONS: Although significant difference was found between the groups 1 to 2 and normal population in terms of CCT, no difference was detected between all the groups in terms of the other parameters. In this study, we report that long-term use of RGP contact lens in patients with keratoconus had no effect on the corneal endothelial cells.