Abstract
Purpose:
To assess the interocular symmetry in spatial distribution of diabetic retinal lesions using ultra-wide-field imaging.
Methods:
Imaging data of patients who had diabetic retinopathy and underwent ultra-wide-field angiography (UWFA) were retrospectively investigated. Fundus in each UWFA image was divided into 2 or 4 subfields by a grid with horizontal and vertical straight lines centered at the fovea. Fundus was also divided into central and peripheral subfields by a rectangle grid. UWFA images taken just after completion of arteriovenous phase were evaluated for microaneurysm (Ma), presumed intraretinal microvascualr abnormalities (IRMA), and non-perfusion area (NPA) on each subfield. Each subfield was scored in a scale of 0-4 for each retinal lesion, based on the detected number of corresponding lesion. Interocular agreements of score in each subfield and interocular agreements of score difference between different subfields were analyzed using a Kappa index.
Results:
Two hundred eighty eight eyes of 144 patients were evaluated; 244 eyes (84.7%) had non-proliferative diabetic retinopathy (NPDR), and 42 eyes (14.6%) had proliferative diabetic retinopathy. Significant interocular agreement was found in the score of Ma (Superior/Inferior: 0.67/0.74, Nasal/Temporal: 0.87/0.89 , Central/Peripheral: 0.89/0.80), presumed IRMA (Superior/Inferior: 0.82/0.87, Nasal/Temporal:0.91/0.76, Central/Peripheral: 0.93.0.89), and NPA(Superior/Inferior: 0.86.0.65 , Nasal/Temporal: 0.87/0.81, Central/Peripheral: 0.97/0.94). High interocular agreement was also found for the score difference between two vertical half subfields, two horizontal half subfields, and central versus peripheral subfields ( P<0.05). A kappa index for intragrader and intergrader agreement was between 0.60 and 0.93.
Conclusions:
There was significant interocular symmetry in the spatial distribution of diabetic retinal lesions. This finding can be useful for the screening examination and longitudinal evaluation of diabetic retinopathy.