Posterior vitreous detachment following panretinal laser photocoagulation

A total of 30 eyes of 19 patients with type I diabetes, varying severity of retinopathy, and no posterior vitreous detachment (PVD) were studied clinically, and vitreous examination was performed by preset lens biomicroscopy. Follow-up was 4.0-7.5 years. A total of 15 eyes underwent panretinal laser photocoagulation (PRP) and 15 eyes were left untreated. The incidence of PVD was 8 of 15 (53%) after PRP and 1 of 15 (7%) in untreated eyes (P\u3c0.02). Minimal vitreous hemorrhage occurred in 4 of 7 treated eyes (57%) that did not develop PVD and in only 2 of 8 (25%) that did. In treated eyes with no history of vitreous hemorrhage, the incidence of PVD was 6/9 (67%); in treated eyes with minimal vitreous hemorrhage at any time, it was 2/6 (33%). In treated eyes, the presence of Diabetic Retinopathy Study (DRS) high-risk characteristics was equally frequent in eyes that developed PVD as in those that did not. These data suggest that PVD occurs following PRP, independent of the severity of diabetic retinopathy or prior vitreous hemorrhage. © 1990 Springer-Verlag

Retinal Circulatory Abnormalities in Type 1 Diabetes

Purpose. To quantify retinal circulatory abnormalities in patients with type 1 diabetes; to compare blood speed and blood flow in major temporal retinal arteries as well as total retinal arterial cross-section measured in patients to that measured in controls without diabetes; to determine which factors are related to the measured abnormalities within the patient group. Methods. The laser Doppler technique and monochromatic fundus photography were used to measure retinal circulatory parameters in 39 patients with type 1 diabetes with duration of diabetes between 7 and 20 years and 13 age-matched controls without diabetes. Blood pressure, intraocular pressure, and heart rate were measured in all subjects. Glycosylated hemoglobin was measured in the patients. Retinopathy was assessed using standardized color fundus photography and fluorescein angiography. Results. Total retinal arterial cross-section was, on average, 17% higher (P = 0.007) in the patients than in the controls, and it increased with increasing duration of diabetes (P = 0.006). Arterial blood speed was, on average, 33% lower (P = 0.0001) in the patients than in the controls, and it decreased with increasing duration of diabetes (P = 0.03). Conclusions. The retinal circulation of patients with type 1 diabetes with no retinopathy or background retinopathy is characterized by dilated major arteries with reduced blood speeds. Dilation of the larger retinal arteries, with the accompanying decrease in vascular resistance to flow in those vessels, appears to counteract an increase in resistance to flow at the level of the smaller retinal vessels. Invest Ophthalmol Vis Sci. 1994;35:2968-2975 V>«irculatory abnormalities in the diabetic retina are primarily influenced by changes in the resistance to flow through the retinal vascular network. Changes in resistance occur when vessels are either dilated or obstructed, or when blood rheologic properties are altered. There is evidence that each of these abnormalities occurs both before and during the development of clinically observable diabetic retinopathy. 1 Nonperfusion and obliteration of small blood vessels is a clinically observable feature of diabetic retinopathy that begins at an early stage. It is seen histologically as an increased prevalence of acellular capillaries. These acellular capillaries, which initially occur singly or in small groups, subsequently occur in larger clusters and are associated with atrophic arterioles. 2 As areas of nonperfusion become more extensive, they are traversed by a few tortuous, enlarged capillaries that ac

Aspirin Effects on Mortality and Morbidity in Patients With Diabetes Mellitus: Early Treatment Diabetic Retinopathy Study Report 14

Objectives.—This report presents information on the effects of aspirin on mortality, the occurrence of cardiovascular events, and the incidence of kidney disease in the patients enrolled in the Early Treatment Diabetic Retinopathy Study (ETDRS).Study Design.—This multicenter, randomized clinical trial of aspirin vs placebo was sponsored by the National Eye Institute.Patients.—Patients (N=3711) were enrolled in 22 clinical centers between April 1980 and July 1985. Men and women between the ages of 18 and 70 years with a clinical diagnosis of diabetes mellitus were eligible. Approximately 30% of all patients were considered to have type I diabetes mellitus, 31% type II, and in 39% type I or II could not be determined definitely.Intervention.—Patients were randomly assigned to aspirin or placebo (two 325-mg tablets once per day).Main Outcome Measures.—Mortality from all causes was specified as the primary outcome measure for assessing the systemic effects of aspirin. Other outcome variables included cause-specific mortality and cardiovascular events.Results.—The estimate of relative risk for total mortality for aspirin-treated patients compared with placebo-treated patients for the entire study period was 0.91 (99% confidence interval, 0.75 to 1.11). Larger differences were noted for the occurrence of fatal and nonfatal myocardial infarction; the estimate of relative risk was 0.83 for the entire follow-up period (99% confidence interval, 0.66 to 1.04).Conclusions.—The effects of aspirin on any of the cardiovascular events considered in the ETDRS were not substantially different from the effects observed in other studies that included mainly nondiabetic persons. Furthermore, there was no evidence of harmful effects of aspirin. Aspirin has been recommended previously for persons at risk for cardiovascular disease. The ETDRS results support application of this recommendation to those persons with diabetes at increased risk of cardiovascular disease.(JAMA. 1992;268:1292-1300