Reflow of obstructed capillaries in the maculae of humans with diabetic retinopathy, observed by fluorescein angiography.

Abstract

SUMMARY As diabetic retinopathy progresses, the non-perfused area in the retina gradually enlarges as the capillaries are obstructed. To elucidate the process of capillary obstruction we examined macular capillaries in 104 diabetics, using fluorescein angiography. The follow-up period was three to eight years. We found that some capillaries in the macula were obstructed, then became unobstructed. Reflow of blood into the macula after the obstruction was observed in nine patients (8.7%). The time between obstruction and reflow varied from two months to four years. There were four cases of simple, three of preproliferative, and two of proliferative retinopathy. Reflow in the capillaries was confirmed as occurring at the same position and in vessels with the same diameter as seen before the obstruction. There was no leakage of the fluorescein dye from the capillary where reflow took place. We tentatively conclude that one of the causes of this phenomenon is a functional obstruction.It is generally accepted that diabetic retinopathy is a form of microangiopathy. As the retinopathy progresses, the non-perfused area in the retina gradually enlarges as a result of obstruction of the capillaries.Although several ophthalmologists reported this phenomenon, each report was of one case and the state of the capillaries before the obstruction was not described.'" Almost all reported that this phenomenon occurred after photocoagulation. We therefore examined the occurrence rate of the reflow of the obstructed capillaries, the type of capillary reflow, and the possible relation to photocoagulation. Subjects and methodsFluorescein angiography was carried out from 1977 to 1985 on 104 eyes of 104 diabetics aged 16 to 78 years. All were treated by diabetologists and the follow-up was for three to eight years. Thirty were cases of insulin-dependent diabetes mellitus (IDDM) and 74 of non-insulin-dependent diabetes mellitus (NIDDM). Diabetics without retinopathy, deterCorrcspondcncc to Yasuo Yamana. MD, Yamana Eye Clinic, 10-Nabeyama Nakama-shi Fukuoka, 809 Japan. mined by ophthalmoscopy, numbered 22. In 58 cases there was a simple retinopathy, 18 had a preproliferative retinopathy, and six a proliferative retinopathy.All patients were examined by ophthalmoscopy after the pupil had been dilated with 10% phenylephrine and 0-5% cyclopentolate. Fluorescein fundus angiography and colour photography were carried out periodically, the frequency depending on the severity of the diabetic retinopathy. 5 ml of 10% sodium fluorescein was given intravenously.We examined coagulation and platelet aggregation at the time of occlusion, and adenosine-5'-diphosphate (ADP) and coagulation were examined at the time of occlusion and after reflow in patient 1 and after reflow in eight patients.

Optical coherence tomography angiography vessel density in children with type 1 diabetes

“…As some previous studies showed that early retinal capillary closure might be transient and reversible the strict control seems to be crucial to prevent the loss of vision in youths with T1D. [ 36 ] The main limitation of the study is poor representativeness of the sample–all subjects were Caucasian, majority of them came from the central part of Poland, and the lack of differences in this clinical population may not reflect the entire cohort of T1D children across the world.…”

Reactive oxygen intermediates increase vascular endothelial growth factor expression in vitro and in vivo.

“…Ischemic diabetic retinal vascular occlusion, resulting from activated granulocytes and monocytes (24), is reversible and reperfusion has been documented angiographically in diabetic eyes (25). Elevated levels of ROI reaction products have been directly correlated with neovascularization in human (26) and rat (27) diabetic eyes, and in eyes with retinopathy of prematurity (28).…”

Retinal Microvascular Patency in the Diabetic Rat

“…It might therefore represent the last reversible stage before further deterioration into irreversible and complete non-perfusion. Yamana et al have shown that some capillaries in the macula were obstructed and then became unobstructed in 8.7% of the diabetic patients whom they followed [12].…”