Evaluation of Choroidal Vascularity Index in Keratoconus Patients: Does Choroidal Vascularity Change in Keratoconus?

To investigate the choroidal structure in keratoconic patients with different severity using the choroidal vascularity index (CVI) derived from image binarization on enhanced depth imaging optical coherence tomography scans (EDI-OCT).

Sixty-eight eyes from 34 keratoconus (KCN) patients and 72 eyes from 36 healthy subjects were recruited in this prospective, noninterventional, comparative cross-sectional study. EDI-OCT was employed to measure choroidal parameters, including choroidal thickness (CT), total choroidal area (TCA), luminal area, stromal area, and CVI.

Subfoveal CT was 354.6 ± 66.8 μm in the control group and 371 ± 64.5 μm in the KCN group (P = 0.86). There was no significant difference between control and KCN groups in terms of TCA (0.66 ± 0.14 mm² vs. 0.7 ± 0.12 mm²; P = 0.70), luminal area (0.49 ± 0.10 mm² vs. 0.53 ± 0.08 mm²; P = 0.67), and stromal area (0.16 ± 0.05 mm² vs. 0.17 ± 0.05 mm²; P = 0.84). CVI was also comparable in the control group (75.4% ±3.4%) and the KCN group (75.6% ±4.5%; P = 0.43). There was also no significant correlation between other choroidal parameters and KCN severity indices.

It seems that CVI as well as other choroidal biomarkers were not significantly different between patients with KCN and healthy subjects.