![]() ![]() On follow-up, the macular edema resolved in the right eye (C). 1: Fundus photos showing retinal edema in the patient’s right eye (A) as compared with the left eye (B). Hypotension may lead to optic neuropathy. Other factors implicated in the pathology are venous stasis, angiospasm, increased blood viscosity (myeloproliferative disorders), hypotension (following hemorrhage), etc. In many clinical situations, thrombocytopenia is associated with anemia, and that leads to defective coagulation and hemorrhages. Retinal hypoxia also leads to vascular dilatation increased transmural pressure owing to hypoproteinemia and microtraumas to the vessel walls, which cause retinal edema and hemorrhages. Anemia causes retinal hypoxia, which leads to infarction of the nerve fiber layer and clinically manifests as cotton wool spots. 3Ī variety of pathologic changes occurring due to and associated with anemia are implicated in the clinical features of anemic retinopathy. As the severity of anemia increases, the risk of retinopathy increases, particularly when the hemoglobin (Hb) level is below 6 gm/dL. 2 EPIDEMIOLOGY and PATHOGENESISĪnemia causes retinopathy in 28% of patients, especially when there is coexisting thrombocytopenia (38%). These were first described by Ulrich in 1883 in association with gastrointestinal hemorrhage. 1 In the eye, anemia can lead to transient retinal hemorrhages. A deficiency of vitamin B12 is known as pernicious anemia. Iron deficiency is the most common type of anemia. In most cases, only treatment of the underlyingĮtiology is needed, and retinopathy generally.Ocular findings can be classified as featuresĬommon to all anemias or specific features due to.Retinopathy increases, especially when platelet As the severity of anemia increases, the risk of.Hypertension correlates with the severity of the diabetic retinopathy. Monkeys with type 2 diabetes have many of the angiopathic changes associated with human diabetic retinopathy. This is the first detailed analysis of retinopathy in a colony of spontaneous type 2 diabetic monkeys. In elastase-digested retinas, the ratio of pericytes to endothelial cells was 0.66:1 in diabetic and 0.64:1 in nondiabetic (P = 0.75) retinas. There was a significant correlation between the occurrence of retinopathy and hypertension (P = 0.037 for systolic pressure P = 0.019 for diastolic pressure). There were apparent fluid-filled spaces in the outer plexiform layer in three of these maculas, suggesting macular edema. Formation of small intraretinal microvascular abnormalities (IRMAs) and microaneurysms were associated with the areas of nonperfusion. Large nonperfused areas extending from optic disc to midfovea were observed in four diabetic monkeys. Dot/blot hemorrhages, cotton-wool spots, and small nonperfused areas were the earliest histologically documented changes in the retinas. ![]() Tissue sections were cut through areas of interest.Ĭotton-wool spots, intraretinal hemorrhages, and hard exudates in the macula were observed by ophthalmoscopy in some diabetic monkeys. Retinas from 16 diabetic monkeys and 6 nondiabetic monkeys were incubated postmortem for adenosine diphosphatase (ADPase) activity (labels viable retinal blood vessels) and flat-embedded in JB-4. Ophthalmoscopic examinations were performed on aged normal and diabetic monkeys. The purpose of this study was to investigate clinically and histopathologically the ocular changes in these monkeys. Type 2 diabetes occurs spontaneously in rhesus monkeys and shows an extraordinary similarity to human diabetes in clinical features and relative time course. ![]()
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