What Is Keratomalacia?

Corneal softening is due to the lack of vitamin A in the early stage of corneal and conjunctival epithelial dryness and deterioration, and corneal stromal cell necrosis and rupture. More common in children under 3 years of age, often involving the eyes.

Basic Information

Visiting department

Ophthalmology

Multiple groups

Children under 3 years

Common causes

Vitamin A deficiency

Common symptoms

Night blindness, corneal and conjunctival epithelial dryness and deterioration

Causes of corneal softening

Mainly due to vitamin A deficiency, the following can occur:

1. Insufficient vitamin A intake

Insufficient intake to maintain the minimum requirements in the body, such as poor feeding and nutritional imbalance during artificial feeding or weaning; or lack of parental health knowledge due to fever and wasting diseases, inappropriate "taboos" such as measles, pneumonia, etc. .

2. Vitamin A malabsorption

Children with gastrointestinal diseases, such as gastroenteritis, indigestion, dysentery, etc., can not absorb vitamin A.

3. Excessive consumption

Toddlers grow too fast, or consume too much during the illness, demand for vitamin A is large, and develop a lack of state.

Corneal softening clinical manifestations

Vitamin A deficiency not only causes epithelial deterioration of the conjunctiva and cornea, but also other epithelial tissue systems such as the skin, digestive tract, respiratory tract, urinary tract mucosal epithelium, and meibomian glands, lacrimal glands and other tissues that have evolved from epithelium. Or less organizational change. The most important of these is the mucosa of the respiratory tract and digestive tract. Pneumonia, bronchitis, and enteritis can occur, and dry skin, weak skin, weak limbs, hoarseness, and diarrhea can occur. The eye signs are mainly the special dryness of the conjunctiva, especially the cleft lip, and the necrotic changes of the corneal stroma. The pathological process is divided into four stages.

Night blindness period

The earliest main symptom of the patient is the loss of the dark adaptation function of healthy eyes in the dark environment. Therefore, the night vision of the patient is much more blurred than during the day, commonly known as "chicken blindness" or "bird blindness". The main cause is vitamin A deficiency, which causes the lack of raw materials for rod-shaped rhodopsin in the retinal neuroepithelial cell layer, which reduces the performance of dark adaptation. Infants are difficult to express because they are young.

2. Early drying

The conjunctival surface of the eyeball loses its normal luster, the corneal surface becomes dull, and the subconjunctival blood vessels present a special violet color. If the lower eyelid is opened and the eye is exposed for 10 seconds, the confusion of the conjunctival and corneal surfaces will rapidly increase. The conjunctiva loses its elasticity. When the eyeball rotates, the conjunctiva shows concentric wrinkles, the corneal sensation decreases significantly, and the instantaneous reaction fails, which accelerates the development of the symptoms of dryness. At this time, a keratoconjunctival epithelial cell scraping smear examination can see keratinized particles of epithelial cells and countless dry bacteria. The discovery of symptoms at this stage is of significance. If early diagnosis and early treatment can be made, it can be cured quickly.

3.Drying period

The conjunctiva of the eyeball is obviously dry, and there can be special silver-white foam-like triangular spots on the conjunctiva of the cleft lip, with the base facing the cornea, called Bitot. On the surface of the cornea, the gloss disappears, and it is cloudy and cloudy, like frosted glass. The corneal limbus at the cleft lip is in contact with the dry patches of the conjunctiva. Cloudiness around the cornea can be accompanied by pigmentary changes. Corneal consciousness can be completely lost, and shaming is obvious.

4. Corneal softening

The bulbar conjunctiva is rough and thick, wrinkles are obvious, corneal infiltration and turbidity are aggravated, and it is grayish yellow or yellowish white. The cornea quickly dissolves into ulcers and pus in the anterior chamber. Generally, the entire corneal tissue can be dissolved and necrotic within 1 to 2 days, eventually forming corneal adhesions, white swollen cornea, or flat cornea. Eyeball atrophy leads to complete blindness. .

Corneal softening test

Perform an eye examination. Low serum vitamin A levels. Urine sediment was positive for keratinocytes.

Corneal softening diagnosis

1. Have a history of fever and wasting diseases, improper artificial feeding or chronic diarrhea and other vitamin A deficiency.

2. Typical clinical symptoms appear.

3. Low serum vitamin A content.

4. Urine sediment was positive for keratinized epithelial cells.

Corneal softening treatment

Corneal softening treatment principles are to improve nutrition, supplement vitamin A, and prevent serious complications. Etiological treatment is the most critical measure to correct malnutrition and strengthen the treatment of primary systemic diseases. Add a lot of vitamin A, and pay attention to vitamin B ₁ or Bco. Topical cod liver oil, antibiotic eye drops and eye ointment are appropriately selected to prevent and treat secondary corneal infections.