Current Treatments of Keratoconus
Transcript of Video by Christopher J. Rapuano, MD - Chief, Cornea Service Wills Eye Hospital
Current Treatments of Keratoconus
Hi, I'm Dr. Christopher Rapuano, Chief of the Cornea Service at Wills Eye Hospital in Philadelphia. I'm coming to you from the Wills Eye Alumni Society Newsroom at Wills Eye Hospital.
I’d like to talk for a little bit about a stepwise treatment to keratoconus. First of all, keratoconus is a relatively common condition. Depending on how it’s defined, it’s between perhaps 1 in 100 and 1 in 1,000 patients in the United States, and in some countries it's actually more common than that. It's a condition where the cornea, which is a clear covering of the eye, becomes thin and protruded or ectatic where it actually begins to bulge out a little bit, and that affects the vision. It's not a nice smooth cornea that can be corrected nicely with glasses, so that people's vision gets blurred with keratoconus. It tends to come on around the age of 15, 20, 25. It tends to progress until the ages of 35, 40, 45, and then it tends to stabilize.
One of the biggest risk factors for getting keratoconus is eye rubbing. So just like your grandmother told you, you should not rub your eyes, and it's good advice for preventing keratoconus from coming on or from keratoconus getting worse.
In mild cases of keratoconus, glasses can work or soft contact lenses, especially soft lenses that correct astigmatism. But for most people with keratoconus, they get their best vision with rigid gas permeable or hard contact lenses. If those don't work, sometimes you can go to a hybrid lens, which is a hard contact in the center with a soft skirt on the outside. If that doesn't work, sometimes you can go to a big scleral contact lens which kind of vaults over the entire cornea.
Some of these lenses are a little trickier to fit than just regular old soft lenses, so most keratoconus patients will seek out contact lens fitters that specialize in keratoconus lens fittings. They tend to have a higher success rate from contact lens specialists who do a lot of keratoconus lens fittings.
Some patients who don't do well with contacts can be treated with Intacs, which are little pieces of plastic, little plastic implants that are placed in the cornea. They can work on occasion, but I personally don’t find them super helpful for a lot of patients. Some patients -- when their keratoconus is really terrible and contacts don't work, or they develop scarring from the contact lenses or from the keratoconus in and of itself -- they can go on to a cornea transplant, where either most of the cornea or the entire cornea can be replaced with a donor cornea. While transplants are big surgeries, they can work very well and people can function extremely well either with glasses or with contacts after transplants.
It’s nice to know that corneal transplants for keratoconus have the highest success rate of all cornea transplants that we do, meaning the vast majority of people will get 20/40 or better vision with correction within a year after surgery, and that vision remains good for decades.
The newest kid on the block as far as treatment of keratoconus is something called corneal crosslinking or collagen crosslinking. This is a procedure which was developed in Europe about 15 years ago, became somewhat widely used about 10 years ago, but five years ago really gained wide acceptance around the world. In the U.S., because of a slower regulatory system, crosslinking was not approved until last year. But now it's available and is being done throughout the United States. I and my partners at Wills Eye were involved in one of the FDA studies for collagen crosslinking several years ago with very good results. And now that it’s FDA-approved, we are performing crosslinking for our keratoconus patients. There are numerous techniques for crosslinking, and we are performing the FDA-approved technique.
The idea behind crosslinking is that it is used for patients where the keratoconus is getting worse, it’s progressing, and the crosslinking procedure can actually halt the progression of keratoconus. That's the idea. Because if you can stop keratoconus where someone is doing well with soft contact lenses or with hard contact lenses, and it doesn't get worse, ideally they can continue with those lenses throughout their lives. Whereas if it progresses and progresses, they may not be able to wear contact lenses and move on to a cornea transplant later on -- which of course is not ideal. Crosslinking is really becoming the standard of care in the United States, now that it is FDA approved, for patients with progressive keratoconus. These tend to be patients between the ages of 15 and 25, 30, 35. Fortunately, most patients over the age of 35, 40, 45 the keratoconus is no longer progressing and they don’t need to have this procedure.
If you have keratoconus or suspect you have keratoconus, you should certainly see your eye care provider. There are certain evaluations that can be done, and then if you're not sure if it's progressing those evaluations can be repeated over time. And if they're nice and stable, crosslinking may not be so beneficial to you. But if the keratoconus appears to be getting worse and worse and worse, we would like to catch that earlier rather than later to prevent it from becoming very bad.
That’s been kind of a whirlwind overview of the current treatments of keratoconus.
I'm Dr. Christopher Rapuano, Chief of the Cornea Service at Wills Eye Hospital coming to you from the Wills Eye Alumni Society Newsroom at Wills Eye Hospital in Philadelphia, Pennsylvania. Thank you very much.
Progressive central/inferocentral corneal thinning and irregularity. It usually develops during teenage or young adulthood years, but can occur later. Almost always bilateral but typically asymmetric.
Decreased vision, frequent change in glasses.
The cause is unknown, but eye rubbing is thought to be a factor in some patients.
Eye rubbing, ocular allergies, occasionally runs in families.
Corneal scarring, acute hydrops (break in Descemet’s membrane resulting in the sudden development of mild or severe corneal edema causing pain, redness and poor vision).
Tests and Diagnosis
Slit lamp examination is essential. Corneal topography and tomography are extremely helpful in identifying mild cases. They are quite useful in monitoring for progression of the condition.
Stepwise approach depends on severity, beginning with glasses, soft contact lenses, toric soft contact lenses, rigid gas permeable contact lenses, hybrid lenses, scleral lenses (including the PROSE lens). Patients who are contact lens intolerant can be treated with INTACS or corneal transplantation such as a deep anterior lamellar keratoplasty or a full thickness corneal transplant. Corneal crosslinking should be considered in eyes with progressive corneal steepening/thinning. All patients should be counseled not to rub their eyes. Ocular allergies should also be treated to reduce the impetus for eye rubbing.
Support: KCN support websites.
NO eye rubbing! Corneal crosslinking can prevent progression.