Choroidal vascular hyperpermeability and submacular haemorrhage in polypoidal choroidal vasculopathy: a multi-field ICGA analysis.

Abstract

To investigate the association between choroidal vascular hyperpermeability (CVH) and the occurrence of submacular haemorrhage (SMH) in polypoidal choroidal vasculopathy (PCV). This retrospective, cross-sectional study included 189 eyes of 159 patients with treatment-naïve PCV. Eyes were categorised into haemorrhage (n=84) and non-haemorrhage (n=105) groups based on the extent of subretinal or subretinal pigment epithelium haemorrhage. Nine-field indocyanine green angiography (ICGA) was performed to evaluate the presence, number, topographic distribution and area of CVH. Logistic regression and correlation analysis were performed to identify factors associated with SMH. The cohort comprised predominantly male patients (67.3%), with a mean age of 65.4±7.6 years. The haemorrhage group showed significantly lower CVH prevalence (32.1% vs 68.6%; p<0.001) and median CVH count (0 vs 1; p<0.001) compared with the non-haemorrhage group. Multivariate model demonstrated that both the presence (p<0.001) and higher count (p=0.004) of CVH were independently associated with a reduced likelihood of SMH. Topographically, this negative association was most pronounced for CVH located in the posterior pole, central nasal and central superior quadrants (all p<0.05). A weak but significant inverse correlation was also observed between the total area of CVH and the area of haemorrhage (Spearman's r=-0.248). The presence and counts of CVH are inversely associated with the occurrence of SMH in PCV, suggesting CVH may serve as a 'pressure-relief window' to dissipate suddenly elevated choroidal vascular pressure which predisposes to vessel rupture.