Ophthalmology: Cornea and External Eye Disease

The cornea is a very small structure in the eye, but it holds the key to clear vision. In fact, the cornea is the most sensitive area of the human body.

When born, the normal cornea is perfectly clear. As we go through life, different processes such as trauma, inflammation, infection and neoplasms—abnormal growths of tissue—can damage the cornea. Once a cornea is damaged, it will not heal clear again and scarring will occur. This scarring prevents light from entering the eye and causes loss of vision. Cornea specialists treat diseases that damage the cornea and preserve useful vision. Fortunately, if damaged, the cornea can often be replaced by corneal transplantation, a surgery to replace the clear surface on the front of the eye. UF Health Ophthalmology at Jacksonville provides complete medical and surgical corneal care.

Common Cornea Problems

  • Corneal abrasion is an injury to the eye that scrapes the corneal surface and causes a loss of superficial tissue.

  • Keratoconus occurs when the cornea undergoes progressive thinning and bulging.

  • Pterygium is a growth on the conjunctiva, a thin membrane that covers the surface of the inner eyelid and the white part of the eyeball. The growth of pterygiums corresponds with wind and sunlight exposure and is more common near tropic and desert areas.

  • Corneal opacity is scarring of the cornea that prevents light from clearly reaching the retina.

  • Fuchs’ Dystrophy is a relatively common condition caused by dysfunction of the corneal endothelial cells (a thin layer of cells lining the back part of the cornea). Although there is a hereditary component, there are also environmental influences such as increased prevalence in the elderly and in females. It manifests as clouding and swelling of the retina. Patients notice decreased vision and eventually ocular discomfort.

  • Corneal infections can be fungal, viral, bacterial or parasitic. Untreated, infections can lead to devastating ulceration and perforation of the cornea.

  • Dry eyes result from a lack of tears, causing a burning or irritated feeling. The cause may be due to systemic changes that affect the eyes’ ability to maintain adequate moisture.

Evaluation and Diagnosis

Diseases of the anterior section of the eye and cornea and infectious eye diseases are the focus of the cornea and external disease service, along with general ophthalmic care and screening for eye complications of systemic diseases and contact lens wear. Adult and pediatric evaluation and consultation are facilitated by advanced diagnostic options and treatment modalities.

Evaluation and treatment of corneal diseases are done primarily by slit-lamp examination, which allows the physician to look at the structures that are at the front of the eye.

Other methods may also be used to aid in diagnosis and treatment, including corneal topography and corneal pachymetry. Corneal topography maps the front surface of the cornea. This topographic map allows for more accurate diagnosis, treatment and follow-up of corneal conditions. Corneal pachymetry measures the cell count and thickness of the cornea. Such information is useful in assessing the overall health of a cornea.

Treatment Options

Treatment options for corneal disease vary widely depending on the nature of the disease and its severity. For corneal infections and corneal surface diseases, there is a wide range of topical medications. For more complex problems, surgery may be needed, ranging from laser resurfacing to corneal transplantation. The indications for surgery depend on a variety of factors and would be discussed with you by your ophthalmologist.

  • Pterygium - An abnormal wedge-shaped growth on the surface of the conjunctiva. This wedge may gradually advance and require surgical removal.

  • Ocular cicatricial pemphigoid - A chronic disease that may be progressive and may cause blistering and scarring of the eye's mucous membranes. This disease also causes severe drying and clouding of the cornea and may be devastating to vision and can involve corneal transplant surgery.

  • Keratoconus - A hereditary, degenerative corneal disease that causes a decrease in visual acuity. In patients with keratoconus, the cornea thins and a cone-shaped protrusion occurs in the central portion of the cornea. Management of this disease is aimed at obtaining the best possible vision, and includes the wearing of specialized contact lenses and/or corneal transplant surgery.

  • Fuchs’ dystrophy - A progressive pathologic corneal disorder characterized by a cloudy and swollen cornea, painful epithelial blisters and reduced vision. This condition, which is sometimes hereditary, may require a corneal transplant.

  • Corneal scarring - Cornea injury from abrasion, laceration, burns, contact lens injury, or disease. Depending on the degree of scarring, vision can range from a blur to total blindness. When corneal scarring is dense enough to affect vision a corneal transplant may be necessary.

Frequently Asked Questions

What are the most common problems that can occur on or in the front of my eye?
Most eye problems are the result of physical damage from hard objects, chemical burns or abrasions, bullous keratopathy and corneal ulcer, corneal scarring, corneal astigmatism and cataracts.

What can I do to correct a problem in the front of my eye?

See your eye care professional. Many conditions associated with the front of the eye are serious and need immediate care.

Is eye protection important when performing household tasks?

Eye protection is very important, even when performing ordinary household tasks. Severe chemical burns can be caused by common household cleaners (bleach, metal polish, etc.). Dusting and vacuuming can stir up particles in the air that can irritate the front of the eye, causing both immediate and long-term damage.

What is a corneal ulcer?

A corneal ulcer is an infection of the cornea. It can be viral, fungal, or bacterial. Ulcers are hard to treat because the cornea does not have blood vessels to allow for our own natural immune system to fight the infection. Therefore, the infection can grow rapidly and cause severe damage to the cornea and eye. Ulcers are typically treated with topical antibiotics. Some ulcers are caused by corneal nerve damage. These are termed neurotrophic ulcers.

What is dry eye?

Tear deficiency affects about 10 to 15 percent of adults. This common disorder can be very uncomfortable. Both decreased tear production and evaporation can play a role. There are many causes of dry eye, but most can be classified as local or systemic. Local causes are due to actual eye or eyelid problems. Systemic causes are varied. Typical systemic causes include inflammatory or rheumatologic diseases, as well as varied medications.

What is a corneal transplant?

A corneal transplant involves removing a portion of the cornea and replacing it with a donor cornea. The donor cornea is generally supplied by an eye bank that harvests and maintains donor eye tissue. It is performed approximately 45,000 times a year in the United States. Indications vary and the decision to transplant is one made by the surgeon and patient. The most common reasons for corneal transplant are pseudophakic corneal edema (presence of an intraocular lens after cataract extraction), Fuchs’ endothelial dystrophy (an eye disease in which cells lining the inner surface of the cornea slowly start to die off), kerataconus and corneal opacification (due to infection or trauma).