peter exception
Introduction
Peter Abnormal Profile In 1897, VonHippel reported a case of bovine eye with central corneal opacity and adhesion to the iris. In 1906, Peter described some cases that are now known as Peteranomaly. For more than a century, there has been a debate about whether the disease is a simple disease or whether it has multiple manifestations of the same manifestation. basic knowledge The proportion of illness: 0.03% Susceptible people: no specific people Mode of infection: non-infectious Complications: cataract Glaucoma
Cause
Peter's abnormal cause
(1) Causes of the disease
The cause of Peter's abnormality is not fully understood, but different changes were found from histopathology and electron microscopy. It is not considered to be a single cause. It was originally thought to be due to intrauterine infection (Von Hipple intracorneal ulcer). This theory is believed to be obtained by amniotic fluid or placenta. Intrauterine keratitis, causing perforation of the cornea, causing the iris-lens to move forward, causing posterior corneal defects, corneal leukoplakia and corneal lens and iris corneal adhesions. These changes can also be caused by deep corneal abscess, pus drainage in the frontal room, no Corneal perforation, foreign reports of 5 of the 21 patients with congenital central corneal thick opacity and central anterior adhesions, in the first 3 months of pregnancy have been viral, especially rubella infection, also reported a case of Peter abnormalities The monocular patient has congenital cytomegalovirus infection, the contralateral eye is normal eye, and a batch of specimens of Peter's abnormal patient are examined by electron microscopy. The cells of the posterior corneal stroma are chronic inflammatory cells, which are destroyed by light microscopy. Abnormal fibroblasts and histiocytes can be seen in the stroma. In patients with abnormal lens, it may be Bubble in the lens and the surface due to incomplete ectoderm.
(two) pathogenesis
There is still debate about the pathogenesis of Peter's abnormality. Tripethi believes that the central corneal defect is due to the ingrowth of the first and second mesenchymal cells at the edge of the cup at 10 to 14 mm of the embryo; the posterior corneal elastic layer Abnormalities and loss of endothelial cells are due to defects in primary mesenchymal cells, which may be further affected by delayed or incomplete separation of lens bubbles; lens opacity and formation of corneal lens cords may be associated with ectoderm In relation to the defects, in summary, the different manifestations of Peter's abnormalities are related to the developmental defects of the corneal endothelium, the corneal stroma and the iris matrix during the three stages of the leaf tissue, which may or may not be accompanied by abnormalities of the lens vacuoles.
Kupfer uses some obstacles in the migration process of neural crest cells or some defects induced by terminal to explain the changes of anterior ocular mesoderm dysplasia and secondary glaucoma including Peter's abnormality, corneal stroma. Migration or terminal induction disorders can lead to a series of corneal opacity and dysplasia. Endothelial cell defects can cause defects in the posterior elastic layer and abnormal corneal water content. This abnormal endothelial cell may have extra "stickiness". , resulting in corneal iris adhesion, partial or total disappearance of the iris matrix can have secondary effects on the iris pigment epithelium and pigment-free epithelium underneath, resulting in a series of pupil abnormalities and pigment epithelial defects, if the defects of the iris matrix develop A certain degree, enough to affect adjacent tissues, such as the lens and its suspensory ligament, can produce lens ectopic and anterior polar cataract.
The migration of trabecular endothelium or the obstacles in the terminal induction process can cause the normal outflow resistance to mutate and lead to an increase in intraocular pressure. This increase in intraocular pressure does not necessarily coincide with the iris strip on the cornea and trabeculae. In proportion to the number, Kupfer et al reported that a 2-year-old child with glaucoma, the ultrastructure of the trabeculectomy specimen showed typical aging changes in the trabecular meshwork, and some scholars believe that the drainage of the aqueous humor may be due to the iris corneal angle. A slight change was made. Others found that Peter's abnormal histopathological changes and complete defects in the retinal pigment epithelial and posterior choroid, found complete peripheral anterior ligament with atrophy of the iris matrix, and no trabeculae were seen. In the mesh and Schlemm tube structure, in other cases, the neural crest cells with iris corneal angle are incompletely differentiated, showing more typical Axenfeld abnormalities and Rieger syndrome.
Prevention
Peter Abnormal Prevention
Handle as early as possible to prevent amblyopia.
Complication
Peter's abnormal complications Complications cataract glaucoma
Some eyes may have corneal lens adhesion in the central part, accompanied by shallow anterior chamber, while some are pre-polar cataracts, 50% to 70% of the eyes develop glaucoma. In addition, Peter abnormalities can also have many uncommon eyes. Abnormalities, including small cornea, small eyeball, flat cornea, corneal sclerosis, iris defect, pupil ectopic, no iris, anterior staphyloma, small lens, congenital aphakic and so on.
Symptom
Peter's abnormal symptoms Common symptoms Edema, short head deformity, elevated intraocular pressure, semi-lateral dysplasia, flexion
Peter's abnormal performance is congenital leukoplakia in the central part of the cornea, and there are defects in the posterior stromal layer and posterior elastic layer in the corresponding part. In the corneal opacity, there is iris adhesion from the center to the periphery, and 8% of the patients are sick with both eyes. Corneal edema may be optional, leukoplakia thick and large can not see the anterior chamber, due to corneal edema, the early cornea has a ground-glass appearance and a little epithelial staining, such as corneal edema aggravation of the lesion, and glaucoma aggravated this situation, However, if the intraocular pressure is normal, the edema will gradually disappear, leaving a corneal scar with a clear boundary and a normal luster epithelium. Although the hardening of the limbus is common, the peripheral cornea is often transparent, and the affected cornea has few blood vessels. form.
Iris and corneal adhesions are often located in the ciliary area of the temporal iris, and there are corneal leukoplakia in the corresponding parts, but the cornea in other directions is more transparent, the adhesion can be local, and can also be extended to the 360° iris ciliary area.
Peter's abnormalities are often accompanied by general anomalies, such as short stature, mental retardation, lip and jaw cleft palate and ear abnormalities, as well as reports of cerebral palsy, small red sputum, no teeth, little teeth, and fingers (toe), flexion , short head malformation, semi-lateral dysplasia, Wilsm tumor, craniofacial osteogenesis imperfecta, hydrocephalus, no brain, lung hypoplasia, Dandy-Walker syndrome, cardiac and genitourinary abnormalities, Lowe syndrome.
Someone has classified Peter's exception into 3 types:
1 without corneal lens adhesion or cataract;
2 with corneal lens adhesion or cataract;
3 accompanied by Rieger syndrome.
Examine
Peter's unusual check
No special laboratory tests.
Infant developmental corneal disease is difficult to treat. It should be done as early as possible under general anesthesia. If possible, photograph or draw corneal and optic nerve morphology, measure corneal transverse diameter, longitudinal diameter and turbidity, and determine optic disc C/ D longitudinal and transverse diameter values, due to abnormalities in the anterior cornea of the patient, tonometry or pneumatic tonometry can be used to measure intraocular pressure. A super, B-ultrasound, ERG and corneal endothelial cells should also be investigated.
Diagnosis
Peter abnormal diagnosis
According to the above-mentioned characteristic clinical manifestations such as the central part of the cornea, the iris and the lens, it is not difficult to make a diagnosis. If there is an increase in intraocular pressure, the diagnosis of secondary glaucoma can be diagnosed. The measurement of intraocular pressure is best done with Tono-pen. The tonometer measures to reduce or be unaffected by corneal leukoplakia.
For newborns and infants, it is mainly to identify central corneal leukoplakia and other causes of corneal opacity. These other causes are congenital glaucoma, mucopolysaccharidosis, birth injury, congenital hereditary corneal dystrophy and corneal opacity. The cornea is turbid, and the tear of the posterior elastic layer is vertical corrugated; the difference between Peter's abnormality and congenital glaucoma is that the corneal diameter is not enlarged, the corneal opacity and the transparent area have obvious boundary lines, and the cornea is cloudy after the intraocular pressure drops. It does not become transparent and has a shallow anterior chamber; the corneal opacity of the mucopolysaccharidosis is diffuse, with a small punctate stromal layer turbidity, and the opacity in the posterior part is denser than the anterior part, and the epithelium and endothelium are not involved; congenital Hereditary corneal endothelial cell dystrophy is not associated with glaucoma, corneal opacity is uniform, anterior chamber is well formed, and there is no obvious iris abnormality; corneal ulcer perforation, iris is embedded in corneal scar, and Peter's abnormal iris is attached to turbid cornea In the vicinity, if the corneal opacity progresses, the anterior chamber condition is more difficult to understand, and it is very difficult to diagnose correctly.
