Keratoconus is an eye disease that affects the structure of the cornea, resulting in loss of vision. Keratoconus occurs in approximately one in 2,000 individuals, typically beginning in puberty and progressing into the mid-30s. Early stages can be treated with glasses, but with progression of the disease into late childhood and early adulthood, corneal transplantation may be needed to restore sight. Corneal collagen cross-linking is a procedure designed to stop the progression of keratoconus or slow it down. Keratoconus is a leading cause of corneal transplantation in the United States. There is no known prevention for keratoconus.
Keratoconus is characterized by the thinning of the cornea and irregularities of the cornea’s surface. The cornea is the clear, outer layer at the front of your eye. The middle layer is the thickest part of the cornea, mostly made up of water and a protein called collagen. Collagen makes the cornea strong and flexible, and helps keep its regular, round shape. This healthy cornea focuses light so you can see clearly. With keratoconus, the cornea thins and bulges into an irregular cone shape, resulting in vision loss.
Keratoconus generally begins at puberty and progresses into the mid-30s. There is no way to predict how quickly the disease will progress, or if it will progress at all. Keratoconus typically affects both eyes, with one being more severely affected than the other.
Although keratoconus has been studied for decades, it remains poorly understood. The definitive cause of keratoconus is unknown, though it is believed that the predisposition to develop the disease is present at birth. A common finding in keratoconus is the loss of collagen in the cornea. This may be caused by some imbalance between production and destruction of the corneal tissue by the corneal cells.
The following may increase the risk of developing keratoconus:
Patients with a family history of keratoconus or with certain systemic disorders, such as Down syndrome, are at a higher risk of developing keratoconus.
Constant inflammation from allergies or irritants can contribute to the destruction of corneal tissue that may result in developing keratoconus.
Chronic eye rubbing is associated with developing keratoconus. It may also be a risk factor for disease progression.
Keratoconus is often discovered in the teenage years. Generally, young patients with advanced keratoconus are more likely to need some form of surgical intervention as the disease progresses.
Other symptoms of keratoconus include:
Glare and halos around lights, Difficulty seeing at night, Eye irritation or headaches associated with eye pain, Increased sensitivity to bright light, Sudden worsening or clouding of vision
Many keratoconus patients are unaware they have the disease. The earliest symptom is a slight blurring of vision or progressively poor vision that is not easily corrected.
In addition to a complete medical history and eye exam, your eye care professional may perform the following tests to diagnose keratoconus:
Treatment of keratoconus focuses on correction of vision and depends on the stage of the disease.