What Are the Most Common Eye Defects?

Causes of eye defects

Eye defect

Eye defects are one of the symptoms and signs of hereditary progressive nephritis. Eye defects, although not as common as deafness, are also common, occurring in 15% to 30% of cases. The generation of these pathogenic gene carriers is related to the heterozygous incomplete penetrance. A variety of eye diseases such as corneal opacity, small cornea, lens dislocation, cataract, glaucoma, macular dysplasia, strabismus, nystagmus, etc., affect the whole eyeball. In some dominant genetic families, there are carriers of pathogenic genes that do not express the disease but can pass the disease to their offspring. The generation of these carriers is related to the heterozygous incomplete penetrance, which is more common in women.

Affected area

head

Related diseases

Corneal secondary glaucoma with iris ciliaryitis, retinitis pigmentosa, congenital glaucoma, nystagmus, deafness, fibrosis syndrome, congenital small eyeballs, orbital cysts, ciliary ring block glaucoma, congenital nystagmus, children's eye-ear- Spondylosis Syndrome Extraocular Myopathy and Amblyopia Extensive Exofibrosis Fibrosis Syndrome Fire Eye Cat Eye Sores Pediatric Eye Pediatric Extraocular Muscle Paralysis-Retinitis Pigmentosa-Cardiac Conduction

Related symptoms

Hemorrhagic tendency proteinuria deafness calcification hypertension corneal opacity lens contraction urinary protein neurodeafness nephrotic syndrome renal failure pupil deformity aphakia congenital non-iris strabismus hematuria thrombocytopenia nystagmus eye defect clitoral hypertrophy purpura

Affiliated Department

Ophthalmology

Related inspections

Ocular and orbital area CT examination fundus examination

Causes of eye defects

1. Sex-linked dominant inheritance (sex-linkeddominantinheritance) is the main inheritance of this disease. Because the pathogenic gene is on the X chromosome, inheritance is related to sex. Mothers and children are also passed on to women, and their children have an equal chance of getting sick, at 50%. The father did not pass on his son, but all his daughters. As such, there are more female patients than male patients in the family. But men are more important than women because women have a normal homologous chromosome (heterozygote), while men do not (hemizygote). In the mid-to-late 1980s, some scholars began to explore the location of the disease-causing gene and found that it was located in the middle of the long arm of the X chromosome (Xq22). However, it was not clear what the mutation was at that time. It was not until 1990 that Myers et al. Confirmed that the mutant gene was a collagen IValpha; chain subunit alpha; 5 (IV) gene, namely COL4A5. However, in 1993, Zhou et al. Found the collagen IValpha; chain subunit alpha; 6 (IV) gene CoL4A6 on this Xq22 site, and confirmed that mutations in COL4A6 can also cause the disease.

2. Autosomaldominantinheritance inherited in this way in 1/7 1/3 families. Because the pathogenic gene is on the autosome, inheritance is not related to sex. The children of the sick father or mother have the same chance of getting sick, about half of them, and the father can pass on the child. The severity of the patient was not related to gender, and the severity of the disease was similar between men and women. After discovering the localization of the pathogenic gene in patients with this disease-linked dominant inheritance, people have been exploring the localization of the pathogenic gene in patients with this genetic mode. It is known that the genes of the other four subunits of the collagen IValpha; chain are on the autosome: the genes COL4A1 and COL4A2 of alpha; 1 () and alpha; 2 () are located on chromosome 13; alpha; 3 () and alpha The 4 (IV) genes COL4A3 and COL4A4 are located on chromosome 2. Which gene mutation or genes caused the disease? Until recently, COL4A3 and COL4A4 on chromosome 2 have not been confirmed.

3. Autosomal recessive inheritance (autosomalrecessiveinheritance) This genetic method has been reported in this disease since 1981, and is now recognized, but there are few such families. Although the disease-causing gene is also on the autosome, the heterozygote has a normal phenotype, but the homozygote shows the disease. Therefore, patients with clinical symptoms are often children of close relatives who are married (both parents are carriers of the disease-causing gene. Their children's chances of getting sick are 1/4, and their chances of becoming normal phenotype carriers are 1/2). The location of the pathogenic gene on the chromosome was also recently identified, and it is also COL4A3 and COL4A4 on chromosome 2.

Examination and diagnosis of eye defects

Kidney manifestation

The main clinical manifestation of Albert syndrome is hematuria, and the affected male patients show persistent microscopic hematuria. Under the age of 20, many patients often experience sudden gross hematuria after upper respiratory infections. Affected women are often heterozygous and may show intermittent hematuria, and 10% to 15% of heterozygous women have never developed hematuria. Affected boys develop hematuria within 1 year of age and are likely to occur as soon as they are born. Boys who have not developed hematuria within the age of 10 are no longer likely to occur.

2. Hearing loss

Deaf men without kidney disease do not pass on to Albert syndrome to their offspring. Early hearing loss can only be detected with hearing tests. Hearing was reduced to 2,000 to 8000 Hz on both sides. Hearing loss in male patients is progressive and will eventually affect other frequencies, including the frequency of sounds. In female patients, hearing loss is less and tends to occur at older ages.

3. Eye defects

Eye defects, although not as common as deafness, are also common, occurring in 15% to 30% of cases. The anterior cone lens (ie, the central portion of the lens forms a conical protrusion of the anterior capsule) is essentially a characteristic lesion of Alport syndrome. Nielson found that all patients with cone-shaped crystals obtained evidence of chronic nephritis and sensorineural hearing loss after careful examination

Eye defects confusing symptoms

Lens shrinkage: Complicated cataracts related to anterior segment diseases. The disease progresses slowly. If local inflammation is controlled, opacity can be stable for a long time without development. As the course of the disease progresses, the degree and range of turbidity continues to increase and expand, eventually affecting the entire lens. During the progression, crystalline substances or calcium deposits can appear in the lens or capsule, and in the later stages, lens shrinkage and even calcification can occur.

Pupil deformation: Pupil deformation refers to abnormal morphology of the pupils, or abnormal responses of the pupils on both sides. Normally round, bilaterally equal, and the pupil responses on both sides are synchronized. It can be oval in glaucoma or intraocular tumors; it can be irregular in shape when the iris is adhered.

Congenital no iris: Aniridia is a developmental disorder in the eyes, which is mainly characterized by congenital dysplasia of the iris or the absence of normal iris. It can also be accompanied by various eye diseases such as corneal opacity, small cornea, and lens dislocation , Cataract, glaucoma, macular dysplasia, strabismus, nystagmus, etc., involving the whole eye.