Abstract
The aim of this study was to investigate foveal and parafoveal microvascular changes in retinal vascular plexuses in patients with type 2 diabetes mellitus (DM) without clinical diabetic retinopathy (NDR) using optical coherence tomography angiography (OCTA) in South Korea. We included 64 patients in the NDR group and included 48 healthy control subjects for comparison. All subjects underwent ocular examination with visual acuity and wide-field fundus photos. Foveal and parafoveal vessel density and foveal avascular zone (FAZ) area (mm2) in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were analyzed. Foveal vessel densities in both the SCP and DCP were decreased in the NDR group compared to the controls (p = 0.034 and 0.001, respectively). Vessel densities in the superior and inferior parafoveae in the DCP were decreased in the NDR group compared to the controls (p = 0.006 and 0.034, respectively). The FAZs of the SCP and DCP were significantly different between the NDR group and the controls (p = 0.003 and 0.001, respectively). The average vessel densities of the SCP and DCP were not correlated with HbA1c, serum creatinine, or the duration of DM in the NDR group. We demonstrated that OCTA can identify early-stage DR before the manifestation of clinically apparent retinopathy in diabetic eyes. Diabetic patients without clinical DR have microvascular alterations (foveal vessel density, parts of the parafovea, and enlarged FAZ) in the SCP and DCP. Our results suggest that OCTA might be a promising tool for early detection of eyes with DR.
Highlights
Diabetic retinopathy (DR) is one of several complications of diabetic mellitus (DM) and an important cause of blindness worldwide [1, 2]
The foveal vascular densities of both the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were significantly lower in the no diabetic retinopathy (NDR) group than in the control group (13:81 ± 4:37% vs. 15:77 ± 3:45%, 11:53 ± 4:41% vs. 13:68 ± 3:59%; p = 0:034 and p = 0:001, respectively)
The average parafoveal vessel densities in both the SCP and DCP were decreased in eyes with DM, only the vessel densities of the superior and inferior parafoveal areas in the DCP were significantly decreased in the NDR group compared to those in the controls
Summary
Diabetic retinopathy (DR) is one of several complications of diabetic mellitus (DM) and an important cause of blindness worldwide [1, 2]. Efforts in early detection and screening for DR could reduce the severity and possibility of blindness. It is necessary to detect and monitor the subtle microvascular changes in patients with DM and subclinical DR. The most common early clinically visible manifestations of DR include microaneurysm formation and intraretinal hemorrhage. Microvascular damage is known to occur before findings of retinopathy become apparent on clinical examination or fundus photography. Fluorescein angiography (FA) is an important modality in revealing capillary leakage and nonperfusion in patients with DM, it is rarely used and not suggested for eyes without visible retinopathy or mild DR
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
