Decreased choroidal thickness could increase vascular endothelial growth factor (VEGF) and cause tissue hypoxia.

, Department of Ophthalmology, University Vita Salute San Raffaele, Milan, Italy, studied a total of 63 eyes of 63 diabetic patients either without diabetic retinopathy (NDR), with diabetic retinopathy [nonproliferative diabetic retinopathy (NPDR)] and no clinically significant macular oedema (CSME).

The mean best-corrected visual acuity was 0.13 ± 0.25 LogMAR and the mean central macular thickness (CMT) was 272.5 ± 16.2 μm in 21 NDR eyes, 294.5 ± 23.5 μm in 21 NPDR/CSME− eyes, and 385.6 ± 75.1 μm in 21 NPDR/CSME+ eyes.

There were no differences in mean subfoveal choroidal thickness between each diabetic group. However, in each diabetic group the mean subfoveal choroidal thickness was significantly reduced compared to the control group.

An overall thinning of the choroid on EDI OCT was witnessed in diabetic eyes. This could lead to tissue hypoxia and could increase VEGF levels, meaning the blood-retinal barrier could break down and cause macular oedema.

The abstract for the study was printed in the 