CORNEA & EXTERNAL DISEASES

Conjunctivitis is an inflammation of the tissue covering the white area of the eye (the sclera) and the inner lining of the eyelids. Common causes are viral infection, bacterial infection, allergy and certain eye drops. Some forms are highly contagious. If left untreated, severe cases can result in vision loss.

Signs and Symptoms

• Scratchy or sandy sensation
• Stinging or burning sensation
• Secretion of mucus
• Redness
• Tearing

Treatment

Observation, proper hygiene and eye drops are often standard treatment but the underlying cause should be determined to prevent recurrence or spread.

Dry eye occurs when tear film abnormalities prevent adequate lubrication of the eyes. While dry eye can be a natural function of aging, it may be a result of climate, medications and certain systemic diseases.

Signs/Symptoms

• Scratchy or sandy sensation
• Stinging or burning sensation
• Secretion of mucus
• Redness
• Tearing

Treatment

Depending on cause and severity, dry eye may be treated with artificial tears, ointments, eye drops or surgery.

The cornea is the clear, central part of the eye’s surface. Keratoconus is a progressive eye disease in which the normally smooth cornea thins and begins to bulge into a cone-like shape. The cone-shaped cornea refracts light incorrectly and causes distorted vision. Keratoconus often begins to develop in the teen years to the early 20s, although it can develop at any age. Changes in the shape of the cornea occur gradually, usually over several years. In most patients with keratoconus, both eyes eventually become affected. Keratoconus can be difficult to detect because it usually develops slowly. While the cause of keratoconus is still unclear, researchers have determined there are certain biochemical and cell biology abnormalities leading to cornea thinning. Excessive eye rubbing has been blamed for causing keratoconus or making keratoconus worse.

Signs/Symptoms

• Distorted and blurred vision
• Myopia (nearsightedness)
• Astigmatism
• Double vision
• Headaches due to eye strain
• Glare
• Light sensitivity

Your ophthalmologist will measure the curvature of your cornea and examine the cornea with a microscope to determine whether symptoms are a result of keratoconus.

Treatment

In the early stages of keratoconus, eye glasses or soft contact lenses may help to correct the nearsightedness and astigmatism associated with the disease. As the condition progresses and the cornea becomes increasingly thin, more advanced treatment is required. Rigid gas-permeable (RGP) contact lenses are usually the next step of preferred treatment. INTACS, plastic rings inserted into the mid-layer of the cornea, may be needed when the distorted vision can no longer be corrected with contact lenses or eyeglasses. Surgery is needed for patients with advanced keratoconus when other therapies no longer provide clear vision. Collagen cross-linking is an investigational treatment method that is currently not approved by the U.S. Food and Drug Administration. In this procedure, eye drops containing riboflavin (vitamin B2) are applied to the cornea and then activated by ultraviolet light. This strengthens the collagen fibers within the cornea.

Keratitis is inflammation of the cornea. Keratitis may be caused by eye trauma, chemical exposure, thermal injury or infection.

Signs/Symptoms

• Pain
• Blurred vision
• Light sensitivity
• Discharge
• Redness
• Corneal haze

Treatment

Antibiotic eye drops, antifungal treatment or corticosteroid therapy are used after the underlying cause is determined. Prosthetic replacement of the ocular surface ecosystem (PROSE) treatment.

A pterygium is a growth on the conjunctiva, which is the delicate membrane covering the white area of the eye (the sclera). A pterygium may invade the cornea and interfere with vision. The exact cause of a pterygium is not known, although significant exposure to sunlight and ultraviolet (UV) rays are suspected factors.

Signs and Symptoms

• Growth on the eye
• Redness
• Foreign body sensation

Treatment

Treatment depends upon severity. Eye drops and ointments may be used to relieve irritation and reduce redness. Surgery may be an option if there is vision interference.