Dilated choroidal vascular channels in pachychoroid neovasculopathy

Abstract

Background: To elucidate the pattern of the choroidal vasculature in exudative pachychoroid neovasculopathy (PNV) and its correlation with the clinical course and treatment outcomes.

Methods: The retrospective study included consecutive patients in National Taiwan University Hospital between 2014 and 2020 who fulfilled the criteria for exudative PNV defined as active type 1 macular neovascularization (MNV) on optical coherence tomography angiography (OCTA) and with leakage on fluorescein angiography (FA) or indocyanine green angiography (ICGA) associated with pachychoroid features. The corrected distance visual acuity (CDVA), FA, ICGA, and OCT images obtained by Optovue (Optovue Inc, Freemont CA, USA) spectral domain OCT were evaluated at baseline and various time points during the 12-month treatment period. The correlations between the choroidal vascular patterns, specifically those with or without dilated choroidal vascular channels (DCVC) revealed by ICGA, and baseline characteristics and treatment outcomes were evaluated using multiple regression models.

Results: The study enrolled 34 eyes of 31 patients. The average age was 59.0 ± 9.3 years, and 20 participants were men. ICGA revealed DCVCs in 21 eyes, while the remaining 13 eyes did not have DCVCs. At baseline, DCVC group was older (p = 0.03) and had a longer duration of visual symptoms (p = 0.02), with a higher vessel density (defined as the percentage of the measured area occupied by flow area) of MNV (p = 0.04), higher proportion of ellipsoid zone disruption (p = 0.01), and poorer CDVA (p = 0.03). After the 12-month treatment period, the frequency of requirement of anti-VEGF injections (p < 0.01) was higher, and the risk for CDVA <20/40 was higher (adjusted OR: 5.29, 95% CI: 1.24-22.48, p = 0.02) in eyes with DCVCs.

Conclusions: For PNV, eyes with DCVCs were associated with higher vessel density of macular neovascularization and poorer CDVA at baseline, and had poorer visual and anatomical outcomes although more anti-VEGF injections were given.

Keywords: dilated choroidal vascular channels; indocyanine green angiography; macular choroidal vasculature; pachychoroid neovasculopathy; visual outcomes.