Evaluation of the optic nerve head and macular vessel density in keratoconus patients using optical coherence tomography angiography- a cross-sectional study.

PURPOSE: Our study evaluated macular and optic disc vascular density (VD) changes in patients diagnosed with keratoconus, as compared with gender and age-matched healthy controls, in relation to the keratoconus stage. METHODS: This comparative cross-sectional study included adult patients who received a diagnosis of keratoconus at the Cornea Clinic. All scans consisted of two 4.5 mm × 4.5 mm images of the optic disc area and 6 × 6 mm images of the macular area using optical coherence tomography angiography. RESULTS: The study included 67 patients (26 women (38.8%) and 41 men (61.2%)) and 74 controls (31 women (41.9%) and 43 men (58.1%)). The mean ages of the keratoconus group and the control group were 30.0 ± 8.0 and 31.1 ± 7.5, respectively. Macular VD (whole, superficial, and deep) and peripapillary VD (whole) values were decreased statistically significant compared with the control group (p < 0.01 and p = 0.015, respectively). The keratoconus stage was negatively correlated with both the macular VD (p = 0.048, r = -0.314) and whole-peripapillary VD values (p = 0.03, r = -0.34). CONCLUSION: Keratoconus might affect the posterior and anterior segments due to similar etiologies, including diminished collagen quality. Therefore, examination of the posterior segment should be performed thoroughly in keratoconus patients.