Childhood cataracts include congenital cataracts and other causes of acquired cataracts.
Congenital cataract is a partial or total clouding of the lens that exists before or after birth, or develops gradually within one year after birth. The pathogenesis can be divided into three categories: genetic, environmental, and unknown causes.
Genetic factors: autosomal dominant (AD), autosomal recessive (AR), and X-linked recessive (XR). Among them, AD type is the most common. Foreign studies have found that about 27% of children with bilateral congenital cataracts have a family history and 2% of children with monocular congenital cataracts have a family history; therefore, it is necessary to be alert if there are congenital cataract patients in the family.
Intrauterine infections: Rubella virus, chickenpox, herpes simplex, measles, herpes zoster and influenza can infect the fetus causing congenital cataracts, with rubella virus being the most common. If the mother has infectious diseases such as toxoplasmosis, rubella, cytomegalovirus and herpes simplex virus in the early stage of pregnancy (1~3 months), the crystal capsule membrane of the fetus is in the formation period at this time, which is easy to be invaded by virus and form cataract. Therefore, if the mother has infection during pregnancy, especially in the early stage of pregnancy, special attention should be paid to whether the baby has congenital cataract after birth.
Congenital dysplasia: Some babies are born and parents find small eyeballs and small corneas and seek timely medical attention, which are likely to be combined with congenital cataracts.
Congenital systemic diseases: such as oculo-cerebral-renal syndrome may be combined with congenital cataracts.
Malnutrition during pregnancy, radiation exposure to the pelvis, and vitamin D deficiency can lead to congenital cataracts. In addition, prematurity and intrauterine hypoxia of the fetus can also lead to congenital cataracts.
Unknown cause: It is mostly an epidemic case, and it is difficult to determine the cause.
Acquired cataracts include traumatic cataracts caused by trauma and concurrent cataracts caused by eye inflammation or other causes.
Traumatic cataracts: Children are active and easily stabbed by sharp objects in the eye. Since they cannot express themselves verbally, smaller wounds can heal by themselves and parents neglect to consult the ophthalmologist, but cataracts will appear when the crystal is injured, and they will gradually worsen and gradually lose vision, causing perceptual strabismus. Rupture injuries are more likely to injure the crystal and cause cataracts, and soon after the injury, the baby will find that the pupil area is white and the vision is not visible.
Cataracts caused by taking certain medications: Children who use glucocorticoids for a long time, for example, may develop clouding under the anterior or posterior capsule. If located in the visual axis area, even small clouding can seriously affect vision, so children who use hormones need to have their ophthalmologists observe the status of the lens regularly.
Metabolic diseases: neonatal hypoglycemia, hyperglycemia, galactosemia, hepatomegaly, impaired cholesterol synthesis, and hypoparathyroidism can often lead to the development of cataracts.
In addition, long-term uveitis, retinal detachment, and post-silicone oil surgery can also cause cataracts to develop.