The cornea is the eye’s outermost layer. It is the clear, dome-shaped surface that covers and protects the front of the eye. The cornea functions like a window that controls and focuses the entry of light into the eye.
Some diseases and disorders of the cornea are:
- Allergies: Allergies affecting the eye are fairly common. The most common allergies are those related to pollen, medications and contact lens wear. Symptoms can include redness, itching, burning and watery discharge. Antihistamine decongestant eye drops can effectively reduce these symptoms.
- Conjunctivitis (Pink Eye): This term describes a group of diseases that cause swelling, itching, burning and redness of the conjunctiva, the protective membrane that lines the eyelids and covers exposed areas of the sclera, or white of the eye. Conjunctivitis can spread from one person to another and affects millions of Americans at any given time. It can be caused by a bacterial or viral infection, allergy, environmental irritants, a contact lens product or eye drops. The infection will clear in most cases without requiring medical care but for some forms of conjunctivitis, treatment will be needed.
- Corneal Infections: Infections may be caused from bacteria or fungi from a contaminated contact lens or if the cornea is damaged after a foreign object has penetrated the tissue, such as from a poke in the eye. These infections can reduce visual clarity, produce discharge and perhaps erode the cornea. Minor infections are commonly treated with anti-bacterial eye drops. If the problem is severe, it may require more intensive antibiotic or anti-fungal treatment, as well as steroid eye drops to reduce inflammation.
- Dry Eye: In people with dry eye, the eye produces fewer or less quality tears and is unable to keep its surface lubricated and comfortable. The main symptom of dry eye is usually a scratchy or sandy feeling as if something is in the eye. Other symptoms may include stinging or burning, a stringy discharge from the eye, and pain and redness. Dry eye can occur in climates with dry air, as well as with the use of some drugs, including antihistamines, nasal decongestants, tranquilizers and anti-depressant drugs. Artificial tears, which lubricate the eye, are the principal treatment for dry eye. Using humidifiers, wearing wrap-around glasses when outside and avoiding windy and dry conditions may bring relief. For people with severe cases, temporary or permanent closure of the tear drain may be helpful.
- Corneal Dystrophies: A corneal dystrophy is a condition in which one more parts of the cornea lose their normal clarity due to a buildup of cloudy material. There are over 20 corneal dystrophies that affect all parts of the cornea. These diseases are usually inherited; affect both eyes; are not caused by outside factors, such as injury or diet; most progress gradually and most can occur in otherwise healthy people, male or female. Some dystrophies cause severe visual impairment, while others cause no visual problems. Some of the most common corneal dystrophies include Fuchs’ dystrophy, keratoconus, lattice dystrophy and map-dot-fingerprint dystrophy.