Association between choroidal thickness and ocular perfusion pressure in young, healthy subjects: Enhanced depth imaging optical coherence tomography study

Purpose. To investigate the correlation of choroidal thickness (CT) with ocular perfusion pressure (OPP) in young, healthy subjects using enhanced depth imaging optical coherence tomography (EDI-OCT). Methods. A single horizontal section and a single vertical section of EDI-OCT scans in each eye of 69 young, healthy subjects were obtained at the macula. CT was measured at the fovea, and up to 3 mm, at intervals of 0.5 mm, away from the fovea in the superior, inferior, nasal, and temporal choroid. Univariable and multivariable analyses were performed to assess the association of CT with OPP while axial length (AL), refractive error (RE), sex, and/or body mass index (BMI), were taken into consideration. Results. Mean subfoveal CT was 307.03 ± 91.27 Lim (mean age, 22.3 ± 3 years; mean axial length, 25.35 ± 1.14 mm; mean refractive error, -3.89 ± 2.02 diopters; mean OPP, 44.18 ± 5.49 mm Hg). Multivariable regression analysis showed that in eyes with <6 diopters of myopia, subfoveal CT (325.92 ± 88.46 Lim) changed most significantly in association with RE and mean OPP (β - 25.941, P < 0.001; β = -3.551, P- 0.042, respectively; adjusted R² - 0.249). In subjects with myopia of >6 diopters, subfoveal CT (225.17 ± 4937 μm) was significantly thinner (P < 0.0001), and a significant correlation with OPP was not observed (P > 0.05). Conclusions. In vivo subfoveal CT as measured by EDI-OCT was significantly associated with OPP in young, healthy subjects when adjusted for RE, suggesting that subfoveal CT may be indirectly indicative of subfoveal ocular perfusion status. This association was not observed in subjects with high myopia.