REGIONAL VARIABILITY IN CHOROIDAL VASCULARITY INDEX AND ASSOCIATION WITH INTERVORTEX ANASTOMOSES IN POLYPOIDAL CHOROIDAL VASCULOPATHY.

PURPOSE: To evaluate the regional variation in choroidal vascularity index (CVI) in polypoidal choroidal vasculopathy and its association with intervortex anastomosis (IA).

METHODS

Fifty-one eyes with polypoidal choroidal vasculopathy were included. Volumetric optical coherence tomography scans were acquired on a 6 × 6 mm 2 macula area and divided into 36 individual squares. Choroidal vascularity index was calculated using an automated algorithm. The different regions were central, superior-temporal, inferior-temporal (IT), superior-nasal (SN), and inferior-nasal (IN). Intervortex anastomosis was detected using en-face optical coherence tomography.

RESULTS

The mean (SD) CVI of the whole macula was 61.01% (1.46), similar to all the other regions (pairwise comparisons, all P > 0.05). Choroidal vascularity index range was 48.75% to 69.48%. The mean (SD) coefficient of variation was 1.9% (1.3). Intervortex anastomosis was present in 64.7% of eyes. Eyes with IA had higher mean (SD) whole macula CVI (61.39% [1.43] vs. 60.30% [1.26], P = 0.01) and subfoveal CT (265.8 µ m [103.4] vs. 190.1 µ m [78.3], P = 0.01) compared to those without, and a lower mean (SD) CVI range (6.08% [2.38] vs. 8.27% [4.13], P = 0.04). Although the mean CVI coefficient of variation was lower in eyes with IA, 1.6% (0.8) versus 2.4% (1.8), this was not statistically significant ( P = 0.14).

CONCLUSION

Regional CVI variability may precede the formation of IA supporting the hypothesis that IA could be a compensatory mechanism for choroidal congestion.