According to the National Eye Institute, keratoconus is the most common corneal dystrophy in the United States, affecting one in 2,000 Americans. Keratoconus is not fully understood, and its progression is unpredictable.
Keratoconus results in thinning and weakening of the cornea which causes blurry and distorted vision. Although genetic and environmental factors are linked to its development, the exact cause is uncertain.
Before considering any treatment, physicians must distinguish between true keratoconus, early keratoconus and suspicions of keratoconus, which may make a difference in some physicians’ decision-making process.
Possible Solutions for Keratoconus
Contacts. During the early stages of keratoconus, glasses or soft contact lenses can correct vision. Rigid contact lenses, hybrid lenses, scleral lenses, or piggyback lenses may help to improve more mild irregular corneal surfaces.
Corneal inserts. Intacs, or corneal inserts, are thin plastic semi-circular rings inserted into the peripheral cornea in order to flatten and regularize the cornea’s shape. The goal of Intacs is the improve a patient’s contact lens or spectacle corrected vision, make the cornea more symmetric, and improve the cornea’s shape for contact lens fitting.
Crosslinking. Corneal cross-linking uses UV light and Riboflavin (Vitamin B2) to strengthen the chemical bonds in the cornea. It was developed in Europe in the late 1990s. Crosslinking has recently been approved by the FDA in April 2016 for the treatment of progressive keratoconus. This recent approval was based on results from 3 parallel, prospective, randomized, open-label, placebo-controlled trials conducted in the U.S. to determine safety and effectiveness. Mid Atlantic Cornea has been among the first groups to offer this treatment in the US and is the most experienced in the Mid Atlantic region.
Topography Guided PRK: Topography-guided laser ablation is not yet approved by the FDA for use in keratoconus. Outside of the United States, topography guided PRK is used in combination with crosslinking, to strengthen the cornea, in order to regularize the shape of the cornea in order to improve vision.
Reasons for Surgical Intervention
The usual criteria for progressing from contact lens correction to a surgical alternative are:
- poor vision even with best fit, well tolerated contact lenses
- reasonably functional vision with contact lens correction but the inability to tolerate or retain the contact lens
- extreme thinning of the cornea either centrally or peripherally that might threaten the integrity of the eye or render surgical correction more complex
The two most common surgical options for keratoconus include Deep Anterior Lamellar Keratoplasty (DALK) and Penetrating Keratoplasty (PK). Our surgeons are among the most experienced in the region with these procedures and have taught numerous surgeons both nationally and internationally in these techniques.
(C) 2011 American Academy of Ophthalmology. Used by Permission