What Is Corneal Degeneration?

Corneal degeneration generally refers to corneal opacity caused by corneal dystrophy and degeneration. The progress of the disease is slow, and the lesions have different shapes. Often bilateral, often without inflammation and irritation such as congestion and pain. Only some patients can develop after inflammation. Pathological tissue section examination, no inflammatory cell infiltration, only in the corneal tissue, various types of degenerative degeneration. Such as steatosis, calcium deposition, hyaline degeneration and so on. The exact cause is unknown, and some manifest as family inheritance.

Corneal degeneration

Corneal degeneration is a rare group of slow-moving degenerative diseases that occur in both eyes at the age of 20-30 years. The primary cause of corneal degeneration is usually ocular inflammatory diseases. A small part of the cause is unknown but has nothing to do with heredity. Malnutrition refers to primary, tissue-histological changes associated with genetic factors.

Corneal degeneration

Classification and pathological changes of corneal degeneration

arcus senilis Corneal degeneration senile ring (arcus senilis)

Senile ring is the most common type of bilateral peripheral corneal degeneration. It manifests itself as a gray-white ring-shaped turbidity in the anterior elastic layer and stroma layer around the cornea, with a width of about 1.5-2.0 mm, and a transparent band separated from the corneal limbus. It often occurs in normal people over 50 years old. Sometimes it can also occur in the young and middle ages, called the youth circle (arcus juvenilis). The pathological manifestations are dense lipid-like deposits in the corneal stroma. Young patients are often accompanied by elevated blood cholesterol. The disease does not affect vision and has no symptoms.

Corneal degeneration corneal degeneration

Corneal limbal degeneration, also known as Terrien's disease, has an unknown etiology and is relatively rare. It is usually bilateral and is common in middle-aged or elderly people. At the initial stage, at the upper edge of the cornea, point-like turbidity first appeared, and then a semilunar sulcus-shaped depression gradually formed, and the stroma became thinner. The surface was covered with new blood vessels and a complete epithelial layer. The edges near the center are sharp and white lines. Due to the thinning of the sulcus tissue, swelling can gradually occur under the influence of intraocular pressure, which often affects vision due to high corneal astigmatism. Perforation or rupture of the cornea can occur when it is unable to withstand intraocular pressure or suffer minor trauma, with iris prolapse. The pathological manifestations are corneal collagen fibrosis and fatty infiltration.

Treatment: First tell the patient not to rub the eyes hard, and prevent accidental injuries. In severe cases, lamellar keratoplasty can be used to repair and strengthen the corneal degeneration area.

Corneal degeneration

Also known as band ker-atopathy

Corneal band degeneration occurs in the exposed area of the cornea at the site of the palpebral fissure, and it appears as a gray band opacity at the anterior elastic layer below the corneal epithelium. The opacity first occurred at the limbus at 3 and 9 o'clock, with a narrow transparent area separated from the periphery of the limbus. Then the turbidity expands from both sides to the center, and finally connects to form a band-shaped turbid area with a narrow middle part, wide ends, and a transverse blepharoplasty. Lesions are often accompanied by calcified white calcified spots. Finally, the lesions can invade the corneal stroma and the appearance of new blood vessels. Irritation may occur in advanced stages. This disease is often a complication of absolute glaucoma, uveitis, and keratitis. It can also occur on atrophied eyeballs. Also seen are systemic diseases with hypercalcemia (such as vitamin D poisoning, parathyroidism, etc.); genetically associated primary banded corneal lesions are rare.

Treatment: In the early stage, after scraping the corneal epithelium, try to use 0.2-0.5% calcium sodium edetate (EDTA-Na) eye drops. In the later stage, if visual function exists or for cosmetic purposes, opacity is limited to those with superficial stroma, and lamellar corneal transplantation is feasible.

Corneal degeneration familial corneal dystrophy

It is a group of hereditary keratopathy or corneal degeneration that violates the corneal stroma.

(1) Granular dystrophy is a type of Groenouw , with autosomal dominant inheritance and symmetrical eyes. It is manifested in the superficial stroma of the central cornea, showing white dot-like turbidity, and different forms of degeneration. The corneal stroma between turbid lesions is transparent. The disease mostly starts before the age of 20, and the puberty is significantly worse. It is progressive. Occasionally, the disease can invade the deep layers of the stroma.

(2) Macularr dystrophy is a type of Groenouw , with autosomal recessive inheritance. It appears in the full-thickness matrix layer, and various turbid spots appear. In the turbid area, the cornea is slightly elevated, and the interstitial matrix presents a slight diffuse turbidity. The lesion can extend to the periphery of the cornea, and the opaque point can increase year by year. There are intermittent irritation symptoms. Advanced corneal epithelium and anterior elastic layer can be violated. Onset of adolescence, progress slowly, but vision can be significantly reduced after middle age.

(3) Lattice dystrophy is also called Haab-climmer-Biber disease. Autosomal dominant inheritance. Eyes affected. Lesions are limited to the superficial layer of the corneal stroma; in addition to speckled opacity, there are also microfilament opaque lines that intersect in a grid or spider web pattern. Onset in childhood, the course of disease is slow. Lesions can invade the epithelial layer and form chronic ulcers after ulceration, which may be accompanied by new blood vessels in the later stages. Most often, vision declines significantly after middle age.

Treatment: There is no special drug treatment method. According to the degree of lesions and visual impairment, lamellar or penetrating corneal transplantation can be selected to improve vision.

Fuchs Corneal degeneration Fuchs endothelial dystrophy

Also known as corneal guttata. Has a familial tendency and is an autosomal dominant genetic disease. It is common in women over 50 years of age, and often invades both eyes. The course of the disease progresses slowly and can be as long as 10 to 20 years. It is mainly caused by spontaneous decompensation of endothelial function, or corneal trauma, inappropriate corneal radial incision, cataract, glaucoma and other corneal endothelium damage and dysfunction caused by internal eye surgery. Corneal degeneration began to appear, and eventually resulted in corneal stroma and epithelial edema and turbidity. Blisters appear under the epithelium, forming what is known as bullous keratopathy. When the blister ruptures, symptoms such as eye pain, fear of light, tears, and foreign body sensation appear, and vision is significantly reduced or lost. Histological examination showed that the elastic layer became thicker, the endothelial cells became thinner, and accompanied by pigmentation.

Hypertonic eye drops can be used early in the treatment, which can relieve symptoms and improve vision. Corneal transplantation is required at an advanced stage.