sickle cell anemia eye disease
Introduction
Introduction to sickle cell anemia Sicklecellanemia is a hemoglobin genetic deficiency disease that can be divided into several types, and the severity of eye lesions varies from type to type. The sickle cells are crescent shaped like a sickle, especially in the hypoxic state. This sputum red blood cell is harder than normal red blood cells and is not easily deformed, so it is easy to block the small arteries of the retina, especially the peripheral small arteries, causing retinal ischemia. Due to hypoxia, tissue is more likely to cause red blood cells to metamorphose, thus causing a vicious circle. basic knowledge The proportion of illness: 0.003% Susceptible people: no special people Mode of infection: non-infectious Complications: vitreous hemorrhage
Cause
Causes of sickle cell anemia
(1) Causes of the disease
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.
(two) 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
Sickle cell anemia eye lesion prevention
Focus on prevention, promote eugenics, and conduct pre-marital and prenatal examinations. Prenatal diagnosis can be performed early in pregnancy using polymerase chain reaction (PCR) and oligonucleotide probe (ASO) methods, or by PCR and restriction endonuclease fragment length polymorphism (RFLP). Prevent the birth of children with homozygotes.
Complication
Sickle cell anemia ocular lesion complications Complications, vitreous retinal detachment
Vitreous blood and retinal detachment.
Symptom
Sickle cell anemia, eye lesions, common symptoms, vitreous
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.
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 peripheral and/or posterior pole retinal vein tortuous expansion; 2 black sunbursts, characterized by In the equator of the retina, there is a clear black spot with a border of 0.5 to 2 PD, similar to the choroidal scar of the retina, but the boundary is not neat or star-shaped or needle-shaped, much like a sunburst with a gemstone embedded in it; 3 flashing point-like deposits (refractile deposits), there are shiny granular small spots near the lesion, similar to cholesterol crystal, but not lipid-like; 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 turns from pink to orange red, and finally turns white; 5 other eye symptoms, there may be conjunctival blood vessels in segments Shape, occasionally combined with vascular-like streaks, or retinal artery or vein obstruction.
Examine
Examination of sickle cell anemia eye lesions
Sickle cell anemia eye lesion examination items: fundus examination, blood routine.
Blood routine is the most common and basic blood test. Blood consists of two major parts, fluid and tangible cells, which are routinely tested for blood. Blood has three different functions of cells - red blood cells (commonly known as red blood cells), white blood cells (commonly known as white blood cells), and platelets. The disease is judged by observing the quantitative change and the morphological distribution. It is one of the commonly used auxiliary examination methods for doctors to diagnose the disease.
Routine blood tests and genetic tests.
Fundus examination is an important method to examine the vitreous, retina, choroid, and optic nerve diseases.
The normal optic disc of the optic disc is slightly elliptical, reddish, with clear boundaries, a funnel-shaped depression in the center, and a slightly lighter color, called a physiological depression.
The central and venous arteries of the retina are bright red, the veins are dark red, and the ratio of arterial to venous diameter is 2:3.
The macular part is located at the side of the eyeball 2 to 2.5 PD (the diameter of the optic disc), slightly below, about one disc or slightly larger, no blood vessels, and the center has a large point of reflective point called the central concave light reflection. .
The retina retina is normal and transparent, and the fundus is evenly dark orange. When there is choroidal vascular permeability, a leopard-like fundus is formed.
Fundus examination can detect ischemic lesions and their complications.
Diagnosis
Diagnosis and diagnosis of sickle cell anemia
Sickle cell anemia is a hemoglobin genetic deficiency disease that can be divided into several types, and the severity of eye lesions varies from type to type.
Repeated joint pain and obvious heart enlargement are easily misdiagnosed as rheumatism. Acute abdominal pain is easily misdiagnosed as acute abdomen. Osteonecrosis can be misdiagnosed as bacterial osteomyelitis. Obvious jaundice can be confused with other causes of jaundice, and should be identified.
