Choroidal vascularity index as an indicator of vascular status of choroid, in eyes with nanophthalmos

Abstract

Purpose To investigate choroidal vascular index (CVI) in eyes with nanophthalmos (NO) with the use of optical coherence tomography (OCT). Methods Macular enhanced depth imaging OCT scans of 25 eyes of 25 patients with NO and age-gender-matched 25 eyes of 25 control subjects were analysed. Images were binarized using the ImageJ software, and total choroid area (TCA), luminal area (LA) and stromal area (SA) were acquired. The main outcome measure was CVI, defined as the ratio of LA to TCA. Results Twenty-five eyes of 25 patients with NO and age-gender-matched control subjects were enrolled. The mean TCA, SA and LA were found to be significantly higher in patients with NO (2.51 +/- 0.44 vs. 1.91 +/- 0.35 mm(2), P < 0.001; 0.86 +/- 0.17 vs. 0.63 +/- 0.13 mm(2), P < 0.001; and 1.65 +/- 0.29 vs. 1.27 +/- 0.23 mm(2), P < 0.000, respectively). on the contrary, CVI did not significantly differ between the two groups (65.72, 67.68, P = 0.099). Conclusion As a novel OCT-based marker, CVI could be used to assess vascular status of the choroid in eyes with NO and can provide better understanding of the pathogenesis of this disease.