Risk Factors of Capillary Nonperfusion Areas Enlargements in Nonproliferative Diabetic Retinopathy

Abstract

Purpose:: A statistically highly significant anatomical relationship was found between capillary nonperfusion and neovascularization. In addition, the frequency of neovascularization increased with the enlargement of capillary nonperfusion area. We present a study with quantitative measurements of capillary nonperfusion and their relation to cumulative metabolic control and other factors.

Methods:: Ten eyes with nonproliferative diabetic retinopathy were evaluated for capillary nonperfusion. None of the 10 eyes received laser photocoagulation until neovascularization was observed. Fluorescein angiography was performed repeatedly during follow-up period at least 2 years. Capillary nonperfusion areas were measured with image analysis software. The correlations between quantitative variables were estimated with the Spearmann coefficient. To investigate which cytokine is related to nonperfusion area, insulin-like growth factor-1 (IGF-1), angiotensin II, soluble intercellular adhesion molecule 1 (sICAM-1) and vascular endothelial growth factor (VEGF) levels in plasma were measured by enzyme-linked immunosorbent assay.

Results:: Although reperfusions of occluded capillary beds were observed, there is a positive correlation between the initial area of capillary nonperfusion and its progression in nonproliferative diabetic retinopathy. The nonperfused areas were found to increase significantly with the cumulative HbA1c index (y=1.1293X+0.193 R²=0.7243 ). There were negative correlations in the enlargements of nonperfused areas with age and diastolic blood pressure, and positive correlations with HbA1c and baseline nonperfused area. In plasama cytokine, there were negative correlation with IGF-1 and VEGF, positive correlation with sICAM-1.

Conclusions:: We conclude that capillary nonperfusion is related to prior glycemic control and to the initial area of capillary nonperfusion. Because of the transformation of capillary nonperfusion areas, leukocyte entrapment in the retinal capillaries might cause capillary nonperfusion, in turn causing diabetic retinopathy.

Clinical Trial:: tokyo women's medical university no480

Keywords: diabetic retinopathy • vascular occlusion/vascular occlusive disease • cytokines/chemokines