Abstract
Purpose: :
Disturbances in retinal perfusion is believed to be involved in the pathophysiology of diabetic retinopathy. These disturbances may be due to changes in the basal diameter of retinal arterioles and to disturbances in the autoregulation of the diameter of these vessels when the blood pressure and the retinal metabolism changes. In vitro studies have shown that prostaglandins are involved in the tone regulation of retinal arterioles, but it is unknown whether this finding is relevant in clinical practise.
Methods: :
Four normal persons and two type 1 diabetic patients below the age of 30 years and with minimal diabetic retinopathy were treated with the prostaglandin agonist xalatan or the prostaglandin synthesis inhibitor voltaren twice per day for one week. The baseline diameter and the diameter change during isometric exercise (pressure autoregulation) of a retinal arteriole was measured before and at the end of the treatment period using the Retinal Vessel Analyzer.
Results: :
In both normal persons and in patients with diabetic retinopathy the prostaglandin agonist xalatan induced a significant (p=0.03) contraction of 9,5 microns (from mean ±5.0 SD) and the prostaglandin synthesis inhibitor a nonsignificant (p=0.11) dilation of the basal diameter of the measured retinal arteriole of 5,5 microns (from mean ±3.9 SD). The diameter response to an increase in the arterial blood pressure was not significantly affected by the treatment.
Conclusions: :
Topical treatment with compounds interfering with the effect of prostaglandins may affect the diameter of retinal resistance vessels and consequently affect retinal blood flow. A prospective randomized study is being planned to assess whether this treatment can be used to modulate flow disturbances in diabetic retinopathy.
Keywords: diabetic retinopathy • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials