Q: I took my 18 year old son for an eye exam recently, and the doctor thinks he may be developing some sort of corneal disease called “keratoconus”. I’ve never heard of this but after reading a little online, I am very concerned. What is the best way to treat this and prevent damage to his eyesight?
A: This may be the least known eye disorder affecting young people, and unfortunately the diagnosis is very commonly missed. Basically, the front of our eye is a clear dome in front of our iris and pupil…..called the cornea. This round shaped tissue focuses light to give us clear vision. Primarily in young people, roughly age 15 to 30, the cornea can grow abnormally, becoming thinner and more cone shaped instead of round. This shape disorder can lead to uncorrectable vision blur, and is completely without any pain.
Fortunately, two simple in-office tests can lead to the correct diagnosis. One measures the thickness of the cornea, called pachymetry. Thinning of the cornea is an early warning sign. Two, we can map the surface of the cornea, called corneal topography, to see if the normal round shape is becoming unusual or irregular. In our clinic, we routinely perform corneal topography for all patients for whom we are prescribing contact lenses. We also do this test, plus pachymetry if we find an unusual increase in astigmatism. Unfortunately, many patients tell us they have never had either test done before.
Treatment may take two forms:
- We can prescribe specialized rigid contact lenses to slow or stop the progressive corneal mis-shaping. This is like orthodontics to alter how your teeth shape your smile. Generally, this is called “ orthokeratology”. These breathable and rigid lenses are quite comfortable and very effective. This treatment often restores clearer vision immediately, when glasses have now failed to restore 20/20 eyesight.
- A procedure called collagen cross-linking can be performed to stiffen the cornea and slow or prevent future irregular shape distortion. This is not a surgery, and sounds very simple. The cornea is saturated with riboflavin drops and exposed to a certain wavelength of UV light. This makes the normally fairly soft and malleable cornea of young people more rigid. The process is a bit like artificially aging the cornea as naturally happens over a lifetime of UV exposure. This is likely why it is very rare to discover keratoconus in people over the age of 50.
Collagen crosslinking is very effective, but does carry some risk of corneal scarring and corneal infection. You and your eye doctor should discuss the pros and cons of both treatments to choose which one to use. Keratoconus is somewhat unpredictable….some cases progress to such vision distortion that corneal surgeries are required to restore some usable vision, while other cases remain mild and much less progressive. Again, based on your son’s age and degree of progression, you and your eye doctor can make a better decision on care.