Abstract
Purpose :
Microaneurysms, a result of retinal ischemia, are an important fundus feature of diabetic retinopathy (DR). However, the spatial relationship has yet to be fully elucidated. We investigated the spatial relationship between retinal flow density (FD) and the number of microaneurysms using optical coherence tomography angiography (OCTA) and fluorescein angiography (FA).
Methods :
Twenty-four DR eyes of 20 patients who visited Kyushu University Hospital and underwent FA and OCTA (3x3mm foveal area) on the same day were analyzed retrospectively. FD of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in a whole 3x3mm area as well as four areas of ETDRS grid were measured, and the number of microaneurysms in these corresponding areas were also counted using FA image in the early phase. Furthermore, FD (SCP and DCP) of the circular area with 500μm diameter centered on each microaneurysm and the control side (superior or inferior) were measured using image J software, respectively. Statistical correlations between FD and the number of microaneurysms in each area were evaluated using Pearson correlation coefficient. FD of the circular area centered on microaneurysms and the control side was compared using Student’s t-test.
Results :
Thirty-two microaneurysms in 24 eyes (nine non proliferative DR and 15 proliferative DR) were evaluated. No significant correlations were shown between FD (SCP and DCP of 3x3mm whole image and four areas of ETDRS grid) and the number of microaneurysms in corresponding areas. FD (SPC and DCP) of the circular area with 500μm diameter centered on each microaneurysm were significantly lower than the control side (p < 0.001).
Conclusions :
Our results using OCTA suggest that proximal but not distal retinal ischemia affects the appearance and occurrence of microaneurysms in DR.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.