Assessment of Choroidal Thickness Inside and Outside of Vascular Arcade in Diabetic Retinopathy Eyes Using Spectral-Domain Optical Coherence Tomography

This study aimed to characterise the distribution of choroidal thickness (CT) in diabetic retinopathy eyes, inside and outside of the vascular arcade, as well as at the fovea, using spectral-domain optical coherence tomography (OCT). Forty-nine healthy eyes, 80 diabetic retinopathy (DR) eyes (59 non-proliferative diabetic retinopathy (NPDR) eyes and 21 proliferative diabetic retinopathy (PDR) eyes) were examined with OCT to obtain nine horizontal lines (far superotemporal, near superotemporal, central, near inferotemporal, far inferotemporal, far superonasal, near superonasal, near inferonasal, far inferonasal) inside and outside of the vascular arcade. Nine points were chosen in 0.5-mm intervals to calculate CT, which was measured at 81 points in each patient. In the DR group, CT decreased significantly, compared with the control group, in all nine horizontal lines except central and near inferotemporal (−29.74 to −36.97 μm, p < 0.05 for all). In the PDR group, CT decreased compared with the NPDR group, in all nine horizontal lines (−6.18 μm to −34.58 μm), but this difference was not significant. In DR eyes, an overall significant reduction of CT was observed inside and outside of the vascular arcade; CT showed a non-significant decrease in PDR eyes, compared with NPDR eyes.