Cornea and External Eye Diseases

UT Southwestern Medical Center’s ophthalmologists have specialized training in identifying and treating cornea disease and other external eye conditions. We offer advanced treatments, including specialized medications and laser surgery, based on the latest research for successful patient outcomes.

Experienced Care for Cornea and External Eye Diseases

The cornea is the clear, outer layer covering the front of the eye. It acts as a barrier to protect the eye from foreign objects, helps with vision by focusing light, and filters ultraviolet rays that enter the eye.

The cornea can usually heal itself after scratches or minor injuries. However, the cornea and other external eye structures require medical treatment for more serious injuries, allergies, inflammation, infections, corneal dystrophies, and a wide range of other conditions.

At UT Southwestern, our eye specialists perform thousands of outpatient surgeries each year, including cornea transplants and other procedures. This level of experience means safe, effective care for our patients and the best possible outcomes.

Types of Cornea and External Eye Diseases

Some of the cornea and external eye conditions treated at UT Southwestern include:

• Acanthamoeba keratitis: This rare but serious infection in the cornea is most often seen in people who wear soft contact lenses and who don’t follow care and wear instructions. Patients initially have eye pain, redness, sensitivity to light, and blurry vision. If untreated, it can lead to permanent vision loss. 
• Benign tumors and pseudotumors
• Blepharitis: Inflammation of the eyelid
• Conjunctivitis: Sometimes called “pink eye,” conjunctivitis means inflammation of the outer covering of the white part of the eye, the conjunctiva. It can result from allergy, irritation, viral infection, or bacterial infection.  Each type has its own symptoms and signs. If an eye is red for more than a day or two, has a lot of discharge, or is painful or blurry, the patient should be examined. 
• Corneal dystrophies: These are a group of conditions of the cornea. Some are mild changes that a doctor can see only with a microscope and which don’t cause any problems. Others, however, can lead to corneal haze or opacities and can affect vision. Many corneal dystrophies run in families.
• Contact lens problems and management of lens-related complications
• Dry eye: As people age, the eye loses some of its ability to make tears. Because the eye is designed to work “under water,” inadequate tears can cause blurry vision as well as irritation. This condition is often treated by using artificial tears, drops, and ointments. There are also medications available to help the eye to make more of its own tears, including Restasis and Xiidra
• Excessive tearing: Often referred to as epiphora, this is a condition in which the eye tears too much. It can be caused by too much tear production, by inadequate drainage of the tears from the eyes, or by malposition of the lower eyelids. Generally, inadequate drainage and malposition of the lids can be surgically corrected.
• Fuchs’ corneal dystrophy: This condition affects the innermost layer of the cornea, the endothelium, causing it to lose the ability to keep fluid from soaking into the cornea.  If the endothelium needs to be replaced, then either DSAEK or DMEK is performed (see below).
• Herpes keratitis: This inflammation and infection of the cornea can be caused by either the herpes simplex virus, which causes the common fever blisters, or by the herpes zoster virus (same as the chicken pox virus) that causes shingles. Both can result in scarring of the cornea and inflammation inside the eye. Patients with herpes simplex infection might experience fever blisters, red eye, blurry vision, and light sensitivity. Patients with herpes zoster might experience mid-face breakouts with shingles and considerable pain. Patients should seek care promptly.
• Injuries to the cornea, including foreign objects lodged in the surface of the eye
• Keratitis: Inflammation or infection of the cornea. There are many causes, but symptoms generally include sensitivity to light, blurry vision, and irritation. This generally needs evaluation and treatment.
• Keratoconus: In some people, the cornea is weak and tends to lose its shape easily and over time, becoming cone shaped and resulting in blurry, out-of-focus vision. 
• Photokeratitis: Photokeratitis is an inflammation of the cornea caused by exposure to light. Exposure can be from welding, too much sun exposure, or overexposure to UV light, such as from a tanning booth. It generally heals completely but can be quite uncomfortable.
• Presbyopia (age-related farsightedness), nearsightedness, farsightedness, and astigmatism: These conditions affect people as they age, especially past age 40. when the natural lens inside the eye, which is behind the pupil, becomes stiffer and can’t change shape as easily for either near or far vision. Prescription glasses are generally the answer.

Causes of Cornea and External Eye Diseases

Medical experts don’t fully understand what causes some conditions affecting the cornea and external eye structures. Some well-known causes include:

• Injury or trauma
• Infection caused by bacteria, viruses, fungi, or parasites
• Hereditary conditions
• Allergic reactions to medications

Cornea and External Eye Diseases

Because there are many cornea and external eye conditions, the symptoms are wide-ranging and include:

• Eye pain
• Sensitivity to light
• Blurry, reduced, or distorted vision
• Excessive tearing
• Redness, itching, burning, stinging, or inflammation in the eye
• Discharge from the eye
• Headache, nausea, fatigue
• Feeling of having something in the eye
• Poor night vision
• Cloudy cornea

Cornea and External Eye Diagnosis

Our ophthalmologists begin with a comprehensive eye exam, which includes:

• Vision test
• Dilated eye test to allow the physician to examine structures inside the eye
• Tonometry, a painless test that measures pressure inside the eye

Other tests we might perform include:

• Slit-lamp examination to look at the structures at the front of the eye
• Contrast sensitivity and glare testing
• Corneal topography to map the cornea’s surface
• Pachymetry to measure the cornea’s thickness
• Keratometry to measure the curve of the cornea
• Blood tests to check for infection or inflammatory disorders