Abstract
Purpose :
Diabetes mellitus (DM) introduces different corneal changes, which are associated to severity of diabetic retinopathy. To identify pathophysiological reasons, corneal tomography and optical densitometry (COD) were combined with retinal oximetry.
Methods :
DM patients and healthy subjects were included. Spatially resolved corneal thickness and COD were assessed using Pentacam HR (Oculus). The pachymetry difference (PACDiff) was calculated as an indicator of peripheral corneal thickness increase. Oxygen saturation (SO2) of retinal vessels was measured by Retinal Vessel Analyzer (Imedos Systems UG). Subsequent, associations between corneal and retinal parameters were analyzed.
Results :
Data of 30 DM patients were compared to 30 age-matched healthy subjects. In DM, arterial (P = 0.048) and venous (P < 0.001) SO2 were increased and arteriovenous SO2 difference was reduced (P < 0.001). In patients, PACDiff was higher than in healthy subjects (P < 0.05), indicating a stronger peripheral corneal thickness increase. COD was reduced in DM (P = 0.004). PACDiff of concentric rings with a diameter of 4 mm (r = -0.404; P = 0.033) to 8 mm (r = -0.522; P = 0.004) correlated inversely to arteriovenous SO2 difference. Furthermore, PACDiff 4 mm was negative associated to arterial SO2 (r = -0.389; P = 0.041) and COD of peripheral corneal areas correlated positive with arterial SO2 (COD total 10 – 12 mm: r = 0.408; P = 0.025).
Conclusions :
The found associations might indicate a common pathogenesis of corneal and retinal changes in DM, which could be caused by reduced oxygen supply, mitochondrial dysfunction, oxidative stress and cytokine effects.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.