thalassemia retinopathy
Introduction
Introduction to globin-producing anorectal retinopathy A globin-producing anemia, also known as sickle cell anemia, is a hemoglobin genetic deficiency disease that can cause retinopathy and is classified into proliferative and non-proliferative types. The main lesion is retinal ischemia and its complications, which are the most common features of other vascular diseases such as diabetic retinopathy, retinal vein occlusion, and retinopathy of prematurity. Because of the abnormal hemoglobin chain, the red blood cells are sickly changed, causing blood circulation obstruction. It is common in African and American colored people, followed by Greece, Turkey, the Middle East and India. The incidence rate can be as high as 20% to 40%. basic knowledge Proportion of disease: the incidence rate is about 0.5% in patients with globin deficiency anemia Susceptible people: no specific population Mode of infection: non-infectious Complications: vitreous hemorrhage
Cause
The cause of globin-induced anemia retinopathy
Cause:
90% to 100% of patients with SS have hemoglobin S, and the sickle cells cause blood flow in the microcirculation to become slow and cause disease.
Pathogenesis
Normal red blood cell hemoglobin is A, a two-sided concave disc, soft and elastic, deformable, easy to pass through capillaries, sickle cell hemoglobin is S or C, crescent-shaped sickle, especially in low oxygen state Change, this sputum red blood cell is harder than normal red blood cells, and is not easy to be deformed, so it is easy to block the small arteries of the retina, especially the peripheral small arteries, causing retinal ischemia. Because tissue hypoxia is more likely to cause red blood cell transmutation, it causes a vicious circle. Blood vessel occlusion causes bleeding, which stimulates retinal pigment epithelial hypertrophy during the repair process, proliferates and migrates, and is mixed with hemosiderin and macrophages to form black sun-decorated needle spots, and retinal flash-like deposits may be contained The hemosiderin is composed of small fragments separated during absorption, and the vascular-like streaks may be formed by rupture of chronic iron deposits on the Bruch membrane due to hemolytic anemia.
Prevention
Prevention of globin-producing anemia retinopathy
1, visual symptoms have blurred vision, one eye or two eyes suddenly decreased vision, black spots or flashes in the field of vision, should be consulted by an ophthalmologist at any time.
2, pay attention to the use of eye health: to avoid staying close to the night and the long interval between the use of the eye.
3, eager to quit smoking; smoking will lead to increased CO in the body caused by relative hypoxia and platelet coagulation, speeding up retinopathy.
Complication
Complications of globin-producing anemia retinopathy Complications, vitreous retinal detachment
Retinopathy, opacity of the vitreous, the fundus is more anterior. Retinal neovascularization, mostly located near the equator, can also be seen in the anterior or posterior pole of the equator. The retina is prominently bulged, and there are blood vessels crawling on the surface, often accompanied by retinal hemorrhage of varying sizes. This symptom indicates that the condition has progressed further.
Vascular changes are seen early in the course of the disease. The arteries and veins have a tortuous expansion. The venous diameter is sometimes greater than 3 to 4 times larger than the normal diameter. Capillaries such as brush-like capillaries are visible at the peripheral end of the retina.
Symptom
Symptoms of globin-induced anemia retinopathy Common symptoms Retinal artery obstruction is often foggy
Divided into proliferative and non-proliferative type 2, the main lesions are retinal ischemia and its complications, which is the most common feature of other vascular diseases such as diabetic retinopathy, retinal vein occlusion, retinopathy of prematurity.
1. Proliferative sickle retinopathy (PSR) is divided into 5 phases:
(1) small artery occlusion: the lesion is located in the peripheral part of the retina, the small artery occlusion is silvery or white-lined, and the venous return is also blocked, forming a peripheral non-perfusion area, the area of the retina is gray-brown, the tissue is blurred, and The normal orange-red fundus is obviously contrasted, and the small blood vessels in the posterior pole are also abnormal, especially in the macular area and the surrounding macular area. There are microangioma-like changes, small arteriolar segmental enlargement, varicose veins are ring-shaped, and the macular center is absent. The vascular region is enlarged, which can be more than 2 times normal. There may be a pathological avascular region around the avascular region, indicating capillary occlusion.
(2) arteriovenous short circuit: at the occlusion of the small arteries, the capillaries on the arterial side are inflated, and communicate with the veins to form arteriovenous traffic branches, often located between the non-perfused area and the perfusion area. Fluorescence angiography sees these arteries and veins. The short-circuited pipe wall does not leak.
(3) neovascular proliferation: neovascularization occurs most often in the periorbital area of the retina, followed by the underarm, the supranasal and subnasal retina, near the arteriovenous short circuit, from the small artery occlusion of the new blood vessels, fan-shaped or group Fan-shaped into the non-perfusion area, similar to other vascular disease neovascularization, early neovascularization is less, only one small artery supply, can develop into multiple small arteries supply over time, or another new group grows nearby Vascular and fluorescein angiography have a large amount of fluorescein leakage. From the classification, neovascularization has the highest incidence of SC disease, accounting for 59% to 92%, followed by Sthal disease, accounting for 33%, and other types are 10%.
(4) Vitreous blood: The neovascularization begins to grow parallel to the retinal surface. Later, the inner limiting membrane penetrates through the base of the vitreous to the center of the vitreous, and leakage leaks into the retina. The new blood vessels can repeatedly attack the vitreous hemorrhage, often misdiagnosed as Eales. Disease, the possibility of this disease for black races, sometimes the new blood vessels retreat due to spontaneous infarction of the nutritional small artery, no vitreous hemorrhage, spontaneous infarction accounted for about 49%.
(5) Retinal detachment: due to the proliferation of new blood vessels, the contraction and traction of the mechanical membrane or the cord, the retina adjacent to the vascular membrane forms a hole, which is oval or horseshoe-shaped, causing retinal detachment, most patients with SC .
2. Nonproliferative sickle retinopathy Non-proliferative lesions include the following:
1 The peripheral part and/or the posterior pole retinal vein is distorted and expanded.
2 black sunbursts, characterized by a black spot with a clear border of 0.5 to 2 PD in the equator of the retina, similar to the choroidal scar of the retina, but the border is not neatly star-shaped or needle-shaped, much like embedded A sunburst with a gemstone.
3 flash refractile deposits, there are shiny granular small spots near the lesion, similar to cholesterol crystals, but not lipidoids.
4 salmon-patch hemorrhage, bleeding into the inner limiting membrane or retina, occasionally enter the retinal pigment epithelium and photoreceptors, oval, 0.75 ~ 1PD red spots, the color changes from pink Orange red, and finally white.
5 other ocular symptoms, may have conjunctival blood vessels in segments, occasionally combined with vascular-like streaks, or retinal artery or vein obstruction.
Examine
Examination of globin-producing anemia retinopathy
1. Fundus fluorescein angiography fundus fluorescein angiography can not only understand the early changes of retinal microcirculation.
2, electroretinogram oscillatory potential (OPs) OPs is a sub-component of electroretinogram (ERG), retinopathy can objectively and sensitively reflect the inner circulation of the retina.
3, fluorescent fundus angiography, in the early arterial or arterial phase, corresponding to the oozing out there are granular, lace-like and other forms of new vascular network. The hemorrhage area obscures the fluorescence, and the upper edge of the bleeding has a translucent fluorescent area. In the late neovascularization, fluorescein leakage forms a strong fluorescent region.
Diagnosis
Diagnosis and diagnosis of globin-producing anemia
Diabetic retinopathy is caused by diabetes. In addition to systemic symptoms characterized by polydipsia, polyphagia, polyuria, urinary glucose, and elevated blood glucose, there are bright red capillary hemangioma in both eyes, flaming hemorrhage, and grayish white in the later stage. Exudation, formation of bright red neovascularization, and fundus changes, which are prone to vitreous red blood, are meaningful for diagnosis and estimation of prognosis. Familial exudative vitreoretinopathy. The lesion is seen in the fundus, similar to the disease. However, most of them are autosomal dominant inheritance, and full-term neonates with spontaneous birth have no history of oxygen inhalation, which is different from this disease.
