Retinal Sensitivity Correlates With the Superficial Vessel Density and Inner Layer Thickness in Diabetic Retinopathy

Abstract

Purpose The purpose of this paper was to present our study on the relationship between the parafoveal sensitivity measured using microperimetry and the vessel density (VD) assessed by optical coherence tomography-angiography (OCT-A) in eyes with diabetic retinopathy (DR). Methods The observational case series was conducted in a tertiary ophthalmology center. Eyes with DR and without macular edema were consecutively included. All eyes underwent microperimetry and OCT-A. The correlation between the regional retinal sensitivity and the corresponding local capillary changes and structural alterations seen on OCT-A was assessed in each retinal quadrant. Results Thirty-seven eyes of 21 patients were included. The mean retinal sensitivity was 28.7 ± 2 decibel (dB). The mean parafoveal VD was 43.2 ± 4.2% in the superficial capillary plexus (SCP) and 48.1 ± 3.3% in the deep capillary complex (DCC). In the multivariate linear regression model, the mean retinal sensitivity was positively correlated with the VD in the SCP in the parafoveal ring ( P = 0.01) and with the inner nuclear layer (INL) thickness ( P = 0.01). The qualitative analysis of each quadrant showed the presence of areas of capillary dropout with a normal sensitivity. Conversely, all areas of decreased sensitivity (<25 dB) were associated with a decreased VD in the SCP and the DCC. Conclusions The parafoveal sensitivity positively correlated with the VD in the SCP in DR eyes. Areas with a low retinal sensitivity were always co-located with a loss of capillaries in the SCP and the DCC despite preserved outer retinal layers.

Derivation of human retinal cell densities using high‐density, spatially localized optical coherence tomography data from the human retina

“…Despite little literature on pathological variations in INL thickness, the various cellular constituents of the INL can be affected in ocular pathologies. For example, in diabetic retinopathy, microaneurysms and macular edema are primarily located in the INL (Chen et al., 2022 ; Das et al., 2018 ; Tsuboi et al., 2021 ), and INL thickness and perfusion have been significantly correlated with functional outputs such as visual acuity and visual field sensitivity (Mokrane et al., 2021 ; Tsuboi et al., 2021 ). Meanwhile, ex vivo studies of human and rodent retinas have revealed changes to the morphology and protein expression of Müller cells and amacrine cells (Gastinger et al., 2006 ; Hammes et al., 1995 ; Mizutani et al., 1998 ), and bipolar cell dysfunction has been observed as a consequence of GC disease and photoreceptor degeneration (Kosta et al., 2021 ; Shen et al., 2019 ).…”

Long-Term Quantitative Analysis of Inner Retinal Dimples and Visual Function Post Internal Limiting Membrane Peeling in Macular Diseases

“…The total of 61 stimulus points covered 20 degrees of visual field. A customized method of two concentric circles was used to delimit 10 degrees and 20 degrees diameter to set up correspondence with parafovea and perifovea, respectively [ 7 , 15 ]. Thus, 28 points were defined in a 10-degree area (1 point at foveal center was excluded on account of avoiding repeat measurement), and 32 points were defined in area between 10 and 20 degrees.…”

Microperimetry in Retinal Diseases

“…They reported that significant correlations were only present in eyes with proliferative diabetic retinopathy. 80 Interestingly, Mokrane et al 81 reported that areas with retinal sensitivity less than 25 dB were always associated with capillary loss, but some areas of capillary loss had a preserved retinal sensitivity.…”

“…In addition to assessing the global function, zonal and local correlations could also be evaluated in detail, thus offering point-to-point structural-functional correlations. A number of studies have reported reduced retinal sensitivity in eyes with diabetic macular ischemia (DMI), which is characterized by reduced vessel density and/or enlarged or disrupted foveal avascular zone 75–78. Importantly, eyes with DMI may have normal visual acuity despite reduced retinal sensitivity suggesting that MP is more sensitive than the visual acuity, or the changes in the sensitivities may precede the reduction of the visual acuity in DMI.…”