Are choroidal vascularity parameters influenced by age, hypertension and visual acuity in pachychoroid spectrum diseases?

Abstract

Purpose: To identify correlations of subfoveal choroidal thickness (SFCT) and choroidal vascularity index (CVI) with age and best corrected visual acuity in eyes with pachychoroid spectrum diseases (PSD) and their association to systemic hypertension using a retrospective study design. Methods: Our study included 82 eyes of 45 patients with PSD: 15 eyes had uncomplicated pachychoroid (UCP), 27 had pachychoroid pigment epitheliopathy (PPE), 32 had central serous chorioretinopathy (CSC) and 8 had pachychoroid neovasculopathy (PNV). All patients underwent DRI TRITON Swept‐Source Optical Coherence Tomography (SS‐OCT). A 1500 mm width subfoveal choroidal area was defined in SS‐OCT B‐scans and divided into luminal area (LA) and stromal area (SA) by the imageJ binarization technique. CVI was defined as the ratio of LA to the total subfoveal choroidal area (TCA). Results: The mean SFCT was 393, 23 ± 95, 65 μm and it was correlated negatively with age (p = 0.003, R = −0.326). We found a negative correlation of TCA and LA with age (p = 0.043, r = −0.227, p = 0.04, r = −0.230). Mean choroidal vascularity index was 64.45 ± 2, 74% with no correlation with age (p = 0.169, R = −0.155). No parameter among SFCT, CVI, TCA, LA and SA had a significant correlation with BCVA or spherical equivalent. Patients with essential hypertension were found to have significantly thinner SFCT when compared with healthy controls (374, 49 ± 83 141 μm vs. 423, 98 ± 130 466 μm, p = 0.046). CVI was not affected by a history of systemic hypertension (64.05 ± 1.97 vs. 64.83 ± 3.3, p = 0.207). The total choroidal area, luminal area, and stromal area, as well as the CVI correlated with SFCT (p < 0.001, r = 0.817, p < 0.001, r = 0.821, p < 0.001, r = 0.750 and p < 0.001, r = 0.371 respectively). Conclusions: SFCT and CVI are dynamic parameters that are affected in patients with pachychoroid diseases. Unlike CVI, SFCT is also affected by age, ocular and systemic factors like hypertension. CVI may be a more specific biomarker for PSD.