Association between Choroidal Vascularity and Prelaminar Tissue Thickness in Healthy and Glaucomatous Eyes

Purpose: To assess the association between the choroidal vascularity index (CVI) and prelaminar tissue thickness (PTT) in healthy and glaucomatous eyes. Methods: The study included 86 eyes with perimetric glaucoma (PG), 86 with pre-perimetric glaucoma (PPG), and 43 age-matched healthy eyes. Total choroidal area (TCA) and CVI were measured by image binarization of spectral-domain optical coherence tomography (SD-OCT) 3.5 mm from the center of Bruch's membrane opening. The CVI was the percentage of choroidal vasculature to choroidal tissue. The association between CVI and PTT measured on a center-horizontal scan of enhanced depth imaging SD-OCT was assessed. Results: The CVI was lowest in PG (61.67% +/- 4.11%), followed by PPG (63.36% +/- 3.54%), and healthy (64.84% +/- 3.13%) eyes (p < 0.001). PG (102.05 +/- 44.01 mu m) had a significantly thinner PTT than PPG (106.16 +/- 38.03 mu m) and the healthy (154.98 +/- 79.46 mu m) eyes (p < 0.001). In a multivariate regression analysis, CVI was associated with PTT and TCA in all subjects, including healthy and glaucomatous eyes (p < 0.05). Conclusions: The CVI and PTT had significantly lower values in glaucomatous eyes than in healthy eyes, and the two parameters were positively associated in all subjects, including healthy and glaucomatous eyes.