Evaluation of Foveal and Parafoveal Microvascular Changes Using Optical Coherence Tomography Angiography in Type 2 Diabetes Patients without Clinical Diabetic Retinopathy in South Korea

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.

Optical Coherence Tomography Angiography in Diabetic Patients: A Systematic Review

“…They identified MAs in only 9.38% of the cases. They found no association between changes in VD occurring in the different plexuses, disease duration, best corrected visual acuity (BCVA), FAZs, or analytical parameters (HbA1c, serum creatinine or e-GRF) [ 72 ].…”

Retinal Microvascular Alterations in Patients with Quiescent Posterior and Panuveitis Using Optical Coherence Tomography Angiography

“…The FAZ area has been shown to correlate well with disease severity and vascular compromise in conditions such as diabetes mellitus. [20][21][22] In the context of quiescent uveitis, the decrease (Is not increase?) in FAZ area compared to control population is a novel finding of our study.…”

Retinal and Corneal Changes Associated with Intraocular Silicone Oil Tamponade

“…Silicone oil tamponade may be associated with decreased macular vessels density, both in SO-filled eye and after ROSO ( Table 4 ). This may affect the superficial capillary plexus (SCP) alone [ 156 , 159 ] or the deep capillary plexus (DCP) alone [ 160 , 161 ], whereas the involvement of both plexuses has been less commonly reported [ 160 ]. On the one hand, it has been hypothesized that the SCP and the superficial retinal layers, being in contact with SO, could be more susceptible to potential SO-related mechanical/cytotoxic damage [ 159 ]; on the other hand, the DCP is considered more susceptible to ischemic damage due to its intraretinal location [ 162 ].…”