Keratoconus is a relatively common degenerative eye disorder that affects about 1 in 1000 people. The disorder is characterized by a thinning of the cornea, the transparent layer on the front of the eye. As the cornea thins, it becomes conical in shape.
Keratoconus can cause a number of visual distortions including blurred vision, multiple ghost images, streaking around light sources, and light sensitivity. In addition, poor visual sharpness and poor night vision are common symptoms of this disorder.
Keratoconus usually starts off with mild symptoms and is most commonly diagnosed in the teenage years. Usually it appears as astigmatism just after the onset of puberty.
Patients may notice the sharpness of their vision (visual acuity) rapidly getting worse, which often causes concern. Some of the symptoms of keratoconus are:
Obviously, many of these symptoms can be caused by conditions other than keratoconus, and keratoconus can be difficult to diagnose. It’s very important to be examined by a highly-qualified ophthalmologist, such as Ilan Cohen MD, who has been trained to recognize the symptoms of keratoconus and who has the skills to microscopically examine and measure the cornea.
Keratoconus is a progressive disorder, but the progression is variable. Some people experience visual stability for years and other have bursts of rapid progression. In general, the disease usually progresses for 10 to 20 years before becoming stable. Most patients with keratoconus who are over 40 years old will have stable vision.
For most people with keratoconus, corrective lenses provide enough visual correction to function normally. Early on, soft contact lenses can be an effective keratoconus treatment to correct astigmatism. As the disorder gets worse, however, most patients need to switch to rigid gas permeable contact lenses (RGPs).
The cone-shape of the cornea makes soft contact lenses less effective. With rigid contact lenses, tear fluid can fill the space between the misshaped cornea and the underside of the lens and produce the effect of a flatter cornea. There are a variety of different contact lenses that are specially designed for those with keratoconus. Fitting contact lenses for those who have keratoconus can be difficult and may require some trial and error by the fitter and the patient. Many of those who suffer from keratoconus will become contact lens intolerant as the disorder progresses.
RGPs can become more and more uncomfortable as the cornea becomes more conical. One cause of discomfort can be scar tissue developing on the part of the cornea that touches the contact lens. At this point, surgical options become necessary. Presently there are two main surgical keratoconus treatment options. The oldest of these treatments is the corneal transplant, also called penetrating keratoplasty.
Corneal transplants are commonly used when scarring has developed from wearing contacts. In a corneal transplant, part of the patient’s cornea is removed and donor corneal tissue is grafted onto the eye. Corneal transplants are the most common transplant procedure in the U.S. and, as a keratoconus treatment, they have a success rate of over 95%.
The corneal transplant procedure itself is typically done as an outpatient procedure under sedation, but the average recovery period is 4 to 6 weeks. It can take up to a year for visual acuity to stabilize completely following a corneal transplant, but, once the eye has stabilized, it should remain stable for the long term.
The main complications of corneal transplants are rejection of the corneal tissue and infection of the eye. Both of these complications can be diminished with preventive medications. Some patients who undergo a corneal transplant can have clear vision restored, but others may not see well even after the transplant. It is possible to treat the visual acuity problems of these patients with contact lenses or glasses. The corneal transplant flattens the cornea and can improve contact lens tolerance. If contact lens intolerance remains a problem, some patients may be candidates for laser eye surgery to give them near perfect vision.
Another surgical keratoconus treatment that is less invasive than corneal transplantation is the use of corneal ring segment inserts known as Intacs. The procedure only takes a matter of minutes and is done on an outpatient basis. Intacs corneal implants are approved by the FDA for keratoconus.
The implantation of these inserts flattens the conical cornea in keratoconus patients to improve vision and increase contact lens tolerance. The procedure involves creating channels in the cornea with a laser or mechanical spreader and inserting one or two crescent-shaped segments made of Plexiglas into those channels. The tunnels are then closed.
The INTACS procedure is routinely performed by cornea specialists like Dr. Ilan Cohen of the 5th Avenue Eye Center and has a very low risk of complications. Opting to have an Intacs procedure can prevent patients with keratoconus from needing a cornea transplant in the future.
Collagen cross linking is another newer keratoconus treatment option. It can be used with or without Intacs. This treatment involves applying riboflavin drops to the cornea and then exposing the cornea to UVA light. The process increases collagen cross linking and improves corneal strength. Early studies have shown this treatment may halt the progression of keratoconus and flatten the cornea to some degree.
A visit to Dr. Ilan Cohen at 5th Avenue Eye Center can provide you with more details about the various keratoconus treatment options and which ones may be right for you. If you’re interested in learning more about keratoconus, LASIK, cataract surgery, or alternative laser vision correction options in Manhattan, Glendale, and Old Bridge NJ, contact us to schedule a consultation.