Early retinal neurovascular impairment in patients with diabetes without clinically detectable retinopathy.

To investigate the function and the corresponding neurovascular structures in patients with diabetes without clinically detectable retinopathy. METHODS : Sixty-six patients with type 2 diabetes without retinopathy (NDR) and 62 healthy controls were recruited. The 16 and 32 Tds flicker electroretinography (ERG) was performed using a mydriasis-free, full-field flicker ERG recording device (RETeval). The vessel density (VD) of superficial capillary plexus (SCP) and deep capillary plexus (DCP), FD300 and ganglion cell complex (GCC) thickness in the macula were quantified using optical coherence tomography angiography (OCTA). The retinal nerve fibre layer (RNFL) thickness and the radial peripapillary capillary (RPC) density in the peripapillary area were also measured with OCTA. Parafoveal and perifoveal VD in both SCP and DCP decreased in NDR group in comparison to control group (all p<0.01). However, macular GCC thickness was comparable between the two groups (p=0.661). Peripapillary RNFL thickness and RPC density were significantly lower in NDR group (p<0.001 and p=0.009, respectively). With regard to ERG parameters, delayed implicit time and decreased amplitude were found in NDR group in comparison to the control group (all p<0.01). In the multiple linear regression analyses, delayed implicit time for 16 and 32 Tds stimuli was significantly correlated with increased HbA1c (β=0.350, p<0.001; β=0.328, p<0.001, respectively) and decreased VD of SCP in the parafoveal region (β=-0.266, p=0.013; β=-0.253, p=0.005, respectively). However, delayed implicit time for 16 and 32 Tds stimuli was not correlated with the thickness of GCC (β=-0.008, p=0.818) in multiple linear regression analyses. Functional and structural impairments have already started in diabetic retina even in the absence of visible retinal lesions. Subtle microvascular abnormalities rather than ganglion cell loss might be associated with early functional changes in NDR patients. Poor control of blood glucose was associated with delayed implicit time of flicker ERG in preclinical diabetic retinopathy.

Zeng Y ，Cao D ，Yu H ，Yang D ，Zhuang X ，Hu Y ，Li J ，Yang J ，Wu Q ，Liu B ，Zhang L ... -  《-》

Retinal vasculature-function correlation in non-proliferative diabetic retinopathy.

Zeng Y ，Cao D ，Yang D ，Zhuang X ，Hu Y ，He M ，Yu H ，Wang J ，Yang C ，Zhang L ... -  《-》

Quantitative Analysis of Microvasculature in Macular and Peripapillary Regions in Early Primary Open-Angle Glaucoma.

Lu P ，Xiao H ，Liang C ，Xu Y ，Ye D ，Huang J ... -  《-》

Evaluation of optical coherence tomography angiography and pattern and flash electroretinography in diabetes mellitus without retinopathy.

Polat Gültekin B ，Hamurcu M 《-》

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

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.

Park YG ，Kim M ，Roh YJ 《-》