Persistent primitive vitreous hyperplasia
Introduction
Introduction to permanent vitreous hyperplasia Persistenthyplastic primary vitreous (PHPV) is a congenital eye abnormality that occurs at birth, which is the result of the original vitreous not degenerating and proliferating behind the lens. basic knowledge The proportion of illness: 0.001% Susceptible people: seen in infants and young children Mode of infection: non-infectious Complications: retinal detachment, lens ectopic
Cause
The cause of permanent vitreous hyperplasia
Causes
It is caused by the developmental disorder of the original vitreous and vitreous vascular system.
Pathogenesis:
The original vitreous is a common product of surface ectoderm, neuroectodermal and mesodermal. As the vitreous artery grows into the optic cup, capillary components are added to the original vitreous. After the sixth week of the embryo, the lens capsule Formation, the relationship between the vitreous and the lens is interrupted, the development of the original vitreous is terminated, and the perpetuating primitive vitreous hyperplasia is mainly the persistence and excessive growth of the original vitreous abnormality, and the intrinsic blood vessels in the vitreous and the branch vessels from the ciliary vessels also continue. Hyperplasia, the ciliary process is associated with the peripheral portion of the membranous tissue and is pulled toward the center during eyeball development. As a result, a dense lens-like fibrous vascular membrane mass is formed in the secondary vitreous. The block can cause spontaneous intraocular hemorrhage, opacity or ectopic lens expansion, and the development of the shallow anterior chamber and anterior chamber is delayed. When the growth rate of the lens and other parts of the eyeball exceeds the vascular membrane mass, the posterior capsule of the lens often ruptures. It quickly forms a cataract and causes the lens to swell, and the fibrous vascular membrane mass after the lens The hemorrhage can enter the membrane tissue, the vitreous and the lens, the fibrous tissue and blood vessels can extend to the defect of the posterior capsule, and the peripheral part of the retina can be continuous with the fibrovascular membrane mass. The pathogenesis of the angle-closure glaucoma includes mainly Due to rupture of the posterior capsule of the lens, the lens expands or the fiber membrane shrinks after the lens, causing the lens-iris to move forward, the pupil is blocked, etc., causing pupillary block, the angle of the chamber is closed, the drainage of the aqueous humor is blocked, the intraocular pressure is increased, and the open angle is The pathogenesis of glaucoma includes chronic uveitis and persistent intravascular hemorrhage of the vascular vascular membrane. After extensive histological studies, 56% of the permanent vitreous hyperplasia is immature, which is also associated with the occurrence of glaucoma. .
Prevention
Perpetual preservation of primitive vitreous hyperplasia
This card is caused by the developmental disorder of the original vitreous and vitreous vascular system. It is mainly used for prevention and health care during pregnancy, so as to avoid abnormal development during the embryonic period, which leads to the occurrence of this disease: pregnant women need to pay attention to regular life, avoid depression, tension, and maintain mentality. Good, at the same time, pay attention to avoid contact with radiation, toxic and harmful substances, avoid the intake of fried and fried foods, and avoid bad living habits such as tobacco and alcohol.
Complication
Perpetual complication of primitive vitreous hyperplasia Complications, retinal detachment, lens ectopic
Spontaneous hemorrhage can occur in the retina, vitreous and lens. When the fiber block adheres to the retina, traction can also produce retinal detachment. Other uncommon complications include rupture of the anterior lens capsule, iris angiogenesis, lens ectopic and iris. , choroid and optic nerve defects.
Symptom
Perpetual symptoms of primitive vitreous hyperplasia Common symptoms Corneal opacity and high intraocular pressure bleeding
The eyeball is less than normal, and 90% is monocular. It is seen in infants and young children. It is characterized by partial or total white sputum. In the shallow anterior chamber, white membranous tissue can be seen behind the lens. Sometimes the membrane contains blood vessels. After the pupil is enlarged, the lens can be seen. The elongated ciliary process is a characteristic manifestation of the disease. The posterior capsule of some eyes has rupture and turbidity, which leads to the occurrence of secondary angle-closure glaucoma. Uncommon iris angiogenesis, complications of this disease are intraocular hemorrhage, secondary glaucoma and corneal opacity. High intraocular pressure can enlarge the corneoscleral enlargement of the infant's eyeball and eventually form a "bull eye".
Examine
Perpetual examination of primitive vitreous hyperplasia
Imaging ultrasound, CT, MRI and other imaging examinations help to confirm the diagnosis; intraocular pressure measurement: in the presence of glaucoma symptoms.
Diagnosis
Diagnosis and identification of permanent vitreous hyperplasia
The most prominent manifestation of this condition is the fibrous vascular membrane mass behind the lens, often seen with chalk disease.
Children should be differentiated from other causes of chalkiness, such as congenital cataract, retinoblastoma, immature retinopathy, B-ultrasound, CT and MRI imaging to help confirm the diagnosis.
