The biggest problem with collagen cross-linking for keratoconus is that we are not doing enough of it.
Depending on how you measure it, the incidence of keratoconus is anywhere from 1% to about 2.3% of the population. That’s about 7.5 million people in the United States. With that prevalence, we should be performing at least 200,000 procedures annually in the U.S. Unfortunately, we’re performing far fewer treatments with cross-linking, according to industry sources I’ve spoken with.
Why are we doing such little cross-linking, especially since insurance plans are starting to cover this procedure? Certainly, there continue to be economic barriers, but sadly, a lack of awareness among eye care providers is probably the biggest barrier. The earliest signs of keratoconus appear on corneal topography, accompanied at first by a subtle shift in refraction and followed by blurred vision. The best way to catch the disease early would be to perform routine screening topography on vision exams. Unfortunately, corneal topography is not available in most optometrists’ and many general ophthalmologists’ offices. Where present, these instruments are generally only used when a corneal disease is suspected or a refractive procedure planned and not for routine patients.
Streak retinoscopy can also detect early signs of keratoconus. Arguably, retinoscopy should be a part of every vision exam to detect irregular astigmatism and higher-order aberrations. Sadly, with the widespread availability of inexpensive autorefractors, retinoscopy has become something of a lost art, even among young optometrists.
One smart company founded by Los Angeles ophthalmologist David Wallace is attempting to address this problem. Intelligent Diagnostics will soon offer a slit lamp-mounted smartphone-driven topography system for under $2,000 (plus a monthly software fee) that should easily and fairly quickly perform a screening topography exam.
What else is keeping us from performing more cross-linking? A lack of relationships. Working together, optometrists who diagnose and follow patients and ophthalmologists who perform these procedures can address this unmet need. Because of the long refractive follow-up, cross-linking procedures are ideal for comanagement, yet few practices have entered into this type of arrangement, which most benefits the patient.
Finally, perhaps the biggest barrier to widespread use of cross-linking to halt keratoconus progression is widespread doubt about how well the procedure works. This is also the saddest barrier because data from both the U.S. and Europe are incontrovertible. Collagen cross-linking halts the progression of keratoconus permanently in the vast majority of patients. The procedures are short, safe and a brief interruption in the patient’s life. Think of it this way: If we had a simple treatment that could be performed at a young age and would forever prevent the at-risk patient from needing a knee replacement in the future, it would be heralded as a miracle. Cross-linking can make that very same claim in preventing future corneal transplants, yet most patients get neither diagnosed nor referred.
For most who perform routine eye exams, if you could save one patient each year from developing a progressive, visually disabling condition, wouldn’t it be worth one small added exam step (topography or retinoscopy)? For most, it would likely be several saves a year. Don’t our patients deserve that?
Disclosure: Hovanesian reports no relevant financial disclosures.