Issue 37.13
Corneal disease consists of a wide ranging spectrum of problems that can affect this very important structure of the eye. The clear protective layer of the front of the eye, the cornea, is responsible for focusing light entering the eye and producing a sharp image on the retina. Think of it like a lens of a camera focusing light on the film. The shape and clarity of the cornea is immensely important for precise vision. Diseases that affect the cornea can result in blurry vision, irritation and sensitivity to light.
Changes in the shape of the cornea can come in many different varieties, one of the most common being a condition called keratoconus. Generally starting in young people in their 20s, this disease causes a progressive weakening of the cornea over 10-20 years. Keratoconus gradually transforms the shape of the cornea from a symmetrically round shape to a cone shape, as well as causing it to thin. This severely affects the eye’s ability to produce a clearly focused image. Early treatment may consist of simply correcting with glasses, though as the disease progresses, specialized rigid gas permeable contact lenses may be needed. Oftentimes, this thinning and protrusion of the cornea becomes extreme, and may necessitate a corneal transplant. A transplant is the replacement of diseased tissue with healthy tissue. The cornea is one of the most common and most successful tissues to be transplanted.
Other conditions that affect the cornea may arise from a problem with only a single layer of the cornea. The cornea is made up of five layers, with the innermost layer consisting of only a single layer of cells called the endothelium. These cells acts like water pumps, pumping out excess water from the cornea to keep it from swelling. Many people, through age, trauma, or genetics have damage to this cell layer, resulting in fluid accumulating in the cornea. The damaged areas are called corneal guttata and can progress to a stage called Fuchs corneal dystrophy. Symptoms include hazy vision in the morning that clears throughout the day, glare, difficulty reading, and poor vision in low light conditions. Surgical intervention is often needed to improve vision, and in the past consisted of a full thickness corneal transplant. However, a new technique of corneal transplantation called DSAEK (pronounced dē’ sek; Descemets’ Stripping Automated Endothelial Keratoplasty) has been in use for the past several years. Instead of the entire cornea being transplanted, only the diseased layer of cells are removed and replaced. The rest of the cornea is left intact, allowing for a much faster recovery and improved outcome.
The cornea can lose transparency due to many different problems. Corneal infections and trauma may lead to scarring, and hereditary corneal dystrophies (a condition where cloudy material builds up in the cornea) may affect the ability of light to pass into the eye. Early detection and treatment may help preserve vision, though surgical options may be needed to improve vision lost from a cloudy cornea.
Jayson Edwards, MD is the only fellowship trained cornea specialist in southern Utah. Dr. Edwards completed his Corneal Fellowship at Tulane University in Louisiana and is now in private practice with the Dixie Ophthalmic Specialists at Zion Eye Institute in St. George. He specializes in diseases affecting the cornea, including keratoconus, corneal dystrophies, infections and ocular surface reconstruction. He performs corneal transplants, DSAEK surgery, LASIK, cataract surgery and other complicated surgeries involving the front of the eye. For more information call 435-656-2020 or visit www.dixieos.com