Reis-Bucklers corneal dystrophy
Introduction
Introduction to Reis-Bucklers corneal malnutrition Reis-Bucklers corneal dystrophy is a more serious anterior corneal malnutrition, an autosomal dominant genetic disease with a strong penetrance. The disease is early onset and can occur before the age of 2 years. At the beginning, it occurs 2 to 4 times a year. At the time of onset, due to corneal epithelial erosion, conscious symptoms such as eye pain, photophobia, and tearing, and congestion, the symptoms begin to relieve after a few weeks of each episode. basic knowledge Sickness ratio: 0.0001% Susceptible people: no special people Mode of infection: non-infectious Complications: keratitis
Cause
Reis-Bucklers Causes of Corneal Malnutrition
Causes:
The disease is an autosomal dominant genetic disease with a strong penetrance. The exact cause is unknown, and it is considered to be the result of primary degeneration of the Bowman layer.
Pathogenesis:
It has been suggested that primary changes in basal epithelial cells do not maintain the integrity of the Bowman membrane and produce curved fibrils associated with denaturation reactions.
Prevention
Reis-Bucklers corneal malnutrition prevention
Generally no special precautions, early detection, early diagnosis, early treatment.
1. Premarital health checkup. A comprehensive system of health checks should be performed prior to the marriage registration process. In particular, it is important to avoid close relatives getting married. Offspring of close relatives who suffer from mental retardation, congenital malformations, and various genetic diseases are several times more likely to marry than non-close relatives.
2. Genetic counseling before pregnancy. Both men and women or one party, if there are genetically ill patients in their relatives, are worried about whether they will have the same genetic disease after marriage, they should be consulted whether they can get married, if the consequences of marriage are serious; one of the two parties has a certain disease, but I do not know Is there a chance of getting a genetic disease, can it be married, and passed on to future generations? The doctor will make a clear diagnosis and give a reasonable treatment.
3. Prenatal screening to avoid the birth of the child. Prenatal screening is mainly for diseases that currently have no good treatment, and the purpose is to prevent the birth of defective children. Usually in the 16th to 20th week of pregnancy, 2-3 ml of peripheral blood of pregnant women should be examined. If the risk of high risk is found (high risk factor exceeds 1/270), further amniocentesis should be taken to confirm the diagnosis.
Complication
Reis-Bucklers corneal dystrophy complications Complications keratitis
Corneal inflammation may occur.
Symptom
Reis-Bucklers corneal malnutrition symptoms Common symptoms Corneal epithelial erosion Eye pain Corneal sensation Reduces visual impairment Photophobia tears congestion
The disease is early onset, and can occur before the age of 2 years. At the beginning, it occurs 2 to 4 times a year. When the attack occurs, the corneal epithelium is smashed and the eye is consciously eye pain, photophobia, tearing and other irritating symptoms and congestion. Each episode lasts for several weeks. Symptoms began to relieve, the frequency of attacks from 10 to 20 years old gradually decreased. After the age of 20 years, due to the formation of white spots on the corneal epithelium, no erosion occurred, but the vision began to decline, the corneal perception also decreased, the course of disease can last for decades, vision Sexual decline, the visual acuity of the eyes in the middle age is obviously impaired.
In the early stage, under the slit lamp, the central part of the corneal epithelium is equivalent to the horizontal layer of the Bowman layer. There are many fine gray-white opacity in the mesh, which is progressively increased and fused, making the surface of the cornea irregular and turbid. , ground pattern, ring shape, honeycomb or fish net shape, and more dense than before, thus affecting vision, corneal sensation is significantly reduced at this time, no new blood vessels protrude into the cornea, and Hudson- is sometimes seen on the rough front surface of the cornea. Stahli line, when the post-illumination method is used later, it can be seen that the shallow layer is granular or frosty, and there is a refractive point of turbidity, which can spread to the peripheral part of the cornea and cause diffuse haze of the corneal stroma, but the cornea The deep layer of the matrix and the endothelial layer are normal.
Examine
Reis-Bucklers corneal malnutrition examination
1. Genetic testing determines the genetic pattern.
2. Pathological examination
(1) Light microscopy: The main pathological changes are corneal epithelial edema, degeneration and structural destruction. In the advanced cases, the thickness of the corneal epithelial cells is different, the epithelial cells have degenerative changes, there are edema between cells and cells, and the corneal structure is destroyed. The epithelial Bowman membrane is absent or thinned, replaced by fibroblast connective tissue membrane and eosinophilic granules, and protrudes into epithelial cells and in the superficial stroma layer. These substances are negative for PAS staining, polysaccharides and starch. The staining is also negative. The epithelial cell basement membrane is either normal thickness or focally absent. The fibrous cell connective tissue is sometimes located between the epithelial cell layer and the Bowman layer, so that the epithelial cell layer is jagged behind, generally without inflammation. However, when the epithelium is eroded and there are focal fibroblasts, there are occasional chronic inflammatory cells.
(2) Electron microscopy: It shows that the ultrastructure of the connective tissue of this fiber cell is inserted into normal collagen fibers by some special filaments to form some irregular dense granular eosin collagen tissue blocks. Some people think that this type Substances may represent decomposition products of Bowman's membranes and superficial matrix layers; it is believed that superficial corneal fibroblasts are involved at a young age, causing them to produce collagenous fibrils (ropocollagen) of abnormal diameter. These special filament diameters are 810nm, short and curly, the middle and thick ends are thinned, the cytoplasm of the epithelial cells is vacuolized, the mitochondria is swollen, the nucleus shrinks, there is no hemidesmosome in the severe lesions, deep matrix fibers and cells, Descemet membrane and The endothelial cells are normal.
Diagnosis
Diagnosis and differentiation of Reis-Bucklers corneal dystrophy
diagnosis
Children with recurrent corneal epithelial erosion and epithelial shedding, typical cellular subepithelial opacity, histological examination of subepithelial crimped fibrils, can be used as a diagnostic basis for Reis-Bückle corneal dystrophy.
Differential diagnosis
1. Thiel-Behnke Honeycomb corneal dystrophy reported by Thiel and Behnke (1967), showing the cellular opacity of the pre-elastic membrane, recurrent epithelial erosion and mild vision loss, autosomal dominant inheritance, not yet confirmed It is an independent disease.
2. Grayson-Wilbrandt corneal anterior membrane dystrophy was first reported by Grayson-Wilbrandt (1966). The clinical manifestations were similar to those of Reis-Bückle corneal dystrophy, but the irritation was mild, the visual impairment was not severe, and the corneal sensation was normal. The anterior elastic membrane has white plaque or reticular opacity and is dominantly inherited.
