Vessel density, retinal thickness, and choriocapillaris vascular flow in myopic eyes on OCT angiography

Purpose: To investigate foveal avascular zone area, macular vascular density, choroidal thickness, and outer retina and choriocapillaris flow in myopic eyes by OCT angiography. Methods: Automated macular maps and flow calculations were retrospectively evaluated in 42 myopic and in 40 control eyes. Results: Myopic eyes presented lower whole superficial vessel density (46.4 ± 4.9 vs. 51.6 ± 3.6%, P < 0.0001) and higher flow area in the outer retina (1.3 ± 0.2 vs. 1.1 ± 0.3 mm², P = 0.0012). Between the myopic and non-myopic eyes, no significant differences could be detected in the choriocapillaris perfusion area (1.9 ± 0.07 vs. 1.9 ± 0.05 mm², respectively; P = 0.55) and in the foveal avascular zone area (0.23 ± 0.1 vs. 0.26 ± 0.1 mm², respectively; P = 0.12). The spherical correction positively correlated with superficial vessel density and negatively correlated with outer retina perfusion (P ≤ 0.0021). The superficial vessel density and the local retinal thickness positively correlated at all macular locations (P < 0.005), especially in the foveal region (P < 0.0001). Conclusions: Eyes with high myopia present reduced superficial vascular density and increased outer retina flow. Superficial vascular density and retinal thickness appear to be significantly correlated.