What Are Congenital Cataracts?

Congenital cataract usually exists before or after birth, or suffers during childhood. The incidence of cataract in our country is 0.05%. Cataracts can cause blindness or amblyopia in infants and young children. 22% to 30% of blind children are caused by cataracts. They are a serious group of blinding diseases that seriously affect children's visual development and have become the second cause of blindness in children. It may be simple cataract or associated with abnormalities in the eyes and other systems.

Basic Information

English name: congenital cataract
Visiting department: Ophthalmology
Common locations: eye

Common causes: Genetics, malnutrition, and metabolic disorders
Common symptoms: Infants: White pupil. Incomplete cataract: low vision, strabismus, nystagmus, etc.

Causes of congenital cataract

About one third of the cases of congenital cataracts have genetic factors, the most common being autosomal dominant inheritance, and some manifest as irregular intergenerational inheritance; recessive inheritance is mostly related to close marriage. Non-hereditary cataract is opacity of the lens caused by local or systemic disorders during embryonic development: fetal intrauterine virus infection during pregnancy, especially in recent years, the high incidence of cataract caused by rubella virus infection during early pregnancy has attracted great attention and occurred in The incidence of cataract caused by rubella infection within 2 months of pregnancy can reach 100%. Malnutrition and metabolic disorders are another major cause of cataract in children, such as maternal gestational diabetes, hyperthyroidism, anemia, low calcium, low vitamin A, late hypoxia, etc., as well as neonatal metabolic disorders such as hypoglycemia and hypoparathyroidism , Galactosemia, etc. Some physical and chemical factors are also one of the causes, such as long-term inhalation of hyperbaric oxygen and exposure to radiation due to various critical illnesses after birth.

Clinical manifestations of congenital cataract

Symptoms

The main symptom of cataract in infants and young children is white pupil. Newborns with white reflection in the pupil area after birth are called cataracts. The most common is congenital cataracts. Incomplete cataracts are often diagnosed with low vision, strabismus, and nystagmus.

2. Signs

(1) Visual function test, vision loss to varying degrees, but should have light response.

(2) The opacity of the crystals in various forms, including total cataract, nuclear cataract, circumnuclear cataract, anterior pole posterior pole cataract, coronal cataract, suture cataract, point cataract and so on.

(3) secondary strabismus, nystagmus.

(4) Other congenital abnormalities of the eye may be complicated, such as small eyeball, small cornea, no iris, perpetual proliferative primitive vitreous body (PHPV), and retinal choroidal lesions.

Types of congenital cataract

Congenital cataract can have complete and incomplete cataracts, and can be divided into nuclear, cortical and membrane cataracts. Because of the different parts, shapes, and degrees of opacity, visual impairment is different. The following are common:

1. Visual dysfunction of nuclear cataract is obvious. Most are diseased in both eyes.

2. Circumferential cataract (laminar cataract) has little visual impact.

3. Anterior polar cataract may not be treated if there is no significant effect on vision.

4. The opacity of the posterior polar cataract has a certain effect on vision.

5. All or nearly all of the cataract lens is cloudy, or it can gradually develop after birth, visual impairment is obvious, and most of them are bilateral.

Congenital cataract examination

Examination of visual function and imaging to rule out concomitant abnormalities in the posterior segment of the eyeball is essential to determine whether surgery is needed. Necessary laboratory tests to rule out metabolic diseases.

Differential diagnosis of congenital cataract

Retinopathy of prematurity

This disease occurs in premature infants with low body weight. Inhalation of high concentrations of oxygen may be the cause. Onset of both eyes.

2. Persistent and proliferative primitive vitreous body

The children are full-term delivery, mostly monocular disease. The affected eyes have small eyeballs, shallow anterior chambers, relatively small crystals, and long ciliary processes, which can reach the posterior pole of the lens. There is a vascular fibrous membrane behind the lens and the upper blood vessels. rich. The posterior pole is cloudy and the iris-crystal septum moves forward.

3. Inflammatory pseudoglioma

Most are onset in both eyes, and a few are monocular. There are white plaques behind the lens, the eyeballs become smaller, and the intraocular pressure decreases. The cause of the disease is the last three months of embryonic development, affected by a mother's infection in the womb, or after birth Caused by neonatal endophthalmitis.

4. Retinoblastoma

It is the most common intraocular malignancy in childhood. Although it usually occurs before the age of 2 to 3 years, it can also develop onset very early, and the white pupil can be seen within a few days after birth. Because the tumor is milky white or yellowish white, when it grows to a certain size, the light entering the eye is reflected into yellowish white.

5. Outer exudative retinitis

The retina has white-yellow lesions, mild bulges, new blood vessels and microhemangiomas on the surface, and dilated capillaries. In severe cases, white pupil reflexes occur due to extensive retinal detachment. Advanced iris neovascularization, secondary glaucoma and iridocyclitis.

6. Retinal dysplasia

The child was born at term, with small eyes, a shallow anterior chamber, and white tissue clumps behind the crystals with white pupils. Often associated with brain dysplasia, congenital heart disease, cleft palate, and polydactyly.

7. Congenital Toxoplasmosis

This disease has been reported in China in recent years. It is characterized by recurrent intraocular inflammation, and pigmentary scarring of the choroidal retina remains in the end. The lesions are more common in the macula, and thus have the appearance of white pupils. May have hepatosplenomegaly, jaundice, hydrocephalus and cerebral calcification.

8. Toxocariasis

The granuloma formed in the fundus of the affected child is clinically divided into two types. One is localized choroidal retinal granulomatosis in the posterior pole without active inflammation, and the other is vitreous opacification with obvious inflammation. Both can cause white pupil reflection. The child has a history of exposure to animals (cats and dogs).

Other rare white pupils include Nonie's disease, posterior pole defect of the fundus, mechanization of vitreous hemorrhage, and severe retinal hyperplasia.

Congenital cataract treatment

1. For cataracts that cause pupil area occlusion, cases with basic visual ability after visual function assessment should be removed as early as possible. In order to prevent recurrence of postoperative cataract, posterior lens capsulotomy and anterior vitrectomy should be performed at the same time.

2. Severe fundus and optic nerve development abnormalities are identified; subjective and objective examinations cannot determine light function; severe small eyeballs are combined; intraocular active diseases are not suitable for surgery.

3. Optometry, eyeglasses, or contact lenses should be used for correction after surgery. After correction of refractive error, amblyopia training was performed to improve vision. Optometry should be performed every six months to one year, and the power of the glasses should be adjusted in time to adapt to the refractive changes caused by eyeball development.

4. For children with monocular cataracts or cases with disparity in eyesight after binocular cataract surgery, amblyopia treatment such as covering should be performed.

5. Implantation of intraocular lens according to the same period of disease or phase II.