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[Vasoconstriction of retinal arterioles with oxygen breathing in diabetic retinopathy]
1Augenklinik Helios Klinikum Erfurt. mblum@erfurt.helios-kliniken.de
Objectives:
The retinal vessel analyzer (RVA) offers the unique opportunity of noninvasive online measurements of retinal vessel diameters. Breathing 100% oxygen is used to test vessel contractility of retinal arterioles in different stages of diabetic retinopathy (DR).
Methods:
After a 3-min baseline measurement 40 patients with diabetes were exposed to 100% oxygen breathing for a 5-min period. The diameter of a retinal arteriole was measured with the RVA continuously during this time. Subjects were divided into four groups according to different stages of DR. Group I: no RD; group II: mild/moderate RD; group III: moderate/severe nonproliferative RD with laser treatment; group IV: proliferative RD with laser treatment.
Results:
Group I (n=12) demonstrated a vasoconstriction of 6.2% (+/-4.0). In group II (n=8) 6.1% (+/-2.8) and in group III (n=8) 6.6% (+/-4.1) vasoconstriction was found. Group IV (n=12) presented a vasodilatation of +2.5% (+/-4,7).
Conclusion:
No significant differences could be found in the vasoreaction to 100% oxygen breathing in different stages of nonproliferative RD. However, a significant reduction could be demonstrated in proliferative DR with this method.