Early Retinal Changes by OCT Angiography and Multifocal Electroretinography in Diabetes

Abstract

Background: To evaluate the earliest retinal morphological and functional changes in diabetic eyes without or with early signs of diabetic retinopathy (DR). Methods: Twenty-two eyes with no DR (noDR group), 22 eyes with mild DR (DR group), and 18 healthy nondiabetic eyes (controls) were enrolled. All eyes were studied by means of spectral domain optical coherence tomography (OCT), OCT angiography (OCTA), and multifocal electroretinogram (mfERG). Results: A significantly higher number of OCT hyperreflective intraretinal foci (HRF) was found in both noDR and DR groups versus controls, but not between DR groups. The OCTA parameters of the superficial vascular plexus (SVP) were significantly reduced in the noDR group both versus controls and DR group (p < 0.05). The OCTA parameters of the intermediate capillary plexus (ICP) were significantly reduced in the DR group versus controls. An increased number of altered hexagons on mfERG was found in the noDR versus the DR group (p = 0.0192). Conclusions: Retinal vascular and functional parameters are differently involved in diabetic eyes; major vascular changes in the SVP and functional alterations of the mfERG are present in diabetic eyes with no clinical microvascular signs of DR, while ICP is mainly involved when early ophthalmoscopic signs of DR are present. The integrated use of mfERG and OCTA provides new significant insights into the pathogenesis of diabetic related retinal disease.

Early Microvascular and Oscillatory Potentials Changes in Human Diabetic Retina: Amacrine Cells and the Intraretinal Neurovascular Crosstalk

“…Using OCT, OCTA, and OP, the present study found that both retinal structural and vascular changes as well as functional ones are precociously present in diabetic eyes, compared to healthy controls, in accordance to previous reports, and that they are related to each other [14,19]. In particular, we found a reduction of VLF and FD of the intraretinal vascular networks at OCTA, representing the length and complexity of retinal microvessels, in diabetic patients with no or early signs of DR, as previously reported [14]. Moreover, we confirmed the presence of early OPs alterations in diabetic eyes compared to healthy controls.…”

“…OCT and OCTA were performed using the Spectralis HRA + OCT2 platform (Heidelberg Engineering, Heidelberg, Germany), as previously described [ 14 ].…”

“…Electroretinography (ERG) has shown to detect early neuronal abnormalities, before clinically detectable DR [ 10 , 12 , 13 ]. We previously reported that different microvascular and functional alterations, detected by means of OCTA and multifocal electroretinogram, may be found in diabetic patients at different early retinal clinical stages [ 14 ]. Oscillatory potentials (OPs), subcomponents of flash ERG, have been reported as one of the most sensitive functional parameters in diabetic eyes, clinically useful also to predict the rate of progression of retinopathy [ 12 , 15 , 16 ].…”

Enhanced Visualization of Retinal Microvasculature via Deep Learning on OCTA Image Quality

“…OCTA provides microvasculature images with higher contrast and better resolution than with fluorescein angiography; furthermore, it contributes to the quantitative evaluation of retinal microvasculature [2]. Currently, OCTA images and quantitative parameters, such as vessel density (VD), have become important markers for retinal disease, and the detailed information of blood flow it provides has contributed greatly to the early detection of multiple eye diseases [3][4][5].…”

“…Although previous studies have reported that denoised images show lower background noise and higher image quality than that of single-scan images of the macular area [11,14], the influence of denoising using commercially available devices on the qualitative and quantitative parameters of the images of both macular and optic areas has not been investigated. The VD is considered an important marker for the early detection of multiple eye diseases; for example, the VD in the macular area can help detect retinal damage in patients with diabetes and hypertension at an early stage, and the VD in the optic area can help in the early diagnosis of glaucoma [3][4][5]. Thus, the VD in both macular and optic areas acquired from denoised images needs to be verified as credible data before its application in the clinical setting.…”