Inflammation and microvascular changes in diabetic retinopathy
Reviewed by Kurt Spiteri Cornish

Studies have shown that neurodegeneration and inflammation in the retina start early in diabetic retinopathy (DR) and can be present before the latter is clinically evident. The aim of this retrospective review of 99 diabetic patients was to evaluate retinal neurodegeneration and aqueous flare intensity as an indicator of blood-aqueous barrier (BAB) breakdown as well as microvascular alternations in diabetic eyes with and without retinopathy. Patients were divided into three groups: group 1 (patients with non-proliferative diabetic retinopathy (NPDR)); group 2 (diabetic patients without clinically overt retinopathy) and group 3 (age-matched controls without diabetes). The thicknesses of individual retinal layers in the foveal area were similar in group 1 and 2, whereas the mean thickness of ganglion cell layer (GCL), inner plexiform layer (IPL), inner retina, outer retina and total retina were significantly thinner in group 1 compared to group 3. The mean capillary non-flow area and foveal avascular zone area were significantly higher in group 1 than groups 2 and 3. There was also a significant correlation between aqueous flare intensity and GCL thickness, inner retinal thickness and total retinal thickness. The authors conclude that neurodegenerative changes in the inner retinal layers in DR correlated with an increase in aqueous flare and macular ischaemia. This suggests that inflammatory factors may play a role in the diabetic retinal neurovascular degeneration. Furthermore, even diabetic eyes without clinically evident retinopathy have a higher prevalence of diabetic retinal neurodegeneration and macular ischaemia compared to controls.

The correlation of inflammation and microvascular changes with diabetic retinal neurodegeneration.
Buyuktepe TC, Demirel S, Batıoğlu F, Özmert E.
CURRENT EYE RESEARCH
2021;46(11):1559-66.