Interocular Symmetry of Optical Coherence Tomography Angiography Parameters in Normal Eyes of Korean Adults

ABSTRACT

PURPOSE: To evaluate the interocular symmetry of microvascular parameters measured by optical coherence tomography angiography (OCTA) in normal eyes of Korean adults. METHODS: We retrospectively reviewed the retinal microvascular structure of 91 healthy Korean subjects (182 eyes). We used OCTA to measure the area of the foveal avascular zone (FAZ), vessel density (VD), and perfusion density (PD) in both eyes. Intraclass correlation coefficients (ICCs), coefficients of variation (CVs), and Pearson correlation coefficients were calculated to evaluate the extent of agreement and correlations between binocular OCTA measurements. RESULTS: Both eyes had similar microvascular characteristics: FAZ area (right eye: 0.31 ± 0.11 mm², left eye: 0.30 ± 0.10 mm², p = 0.98), FAZ perimeter (right eye: 2.35 ± 0.45 mm, left eye: 2.36 ± 0.39 mm, p = 0.86). VD 1-mm center (right eye: 9.42 ± 2.75, left eye: 9.14 ± 2.96, p = 0.163), full area (right eye: 19.94 ± 1.65, left eye: 19.72 ± 1.76, p = 0.285), and PD 1-mm center (right eye: 0.16 ± 0.05, left eye: 0.16 ± 0.05, p = 0.151), full area (right eye: 0.36 ± 0.03, left eye: 0.36 ± 0.04, p = 0.716). All ICC values were above 0.8 and all CVs below 10%. CONCLUSIONS: The microvascular structure, as represented by the VD, PD, and FAZ area measured via OCTA, was bilaterally symmetric in normal eyes of Korean adults.