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BLOG: But for the FDA, CXL is already standard of care
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In many ways, the U.S. leads the world in creating new medical standards. In so many others, we lag terribly. Europe, for example, now largely considers intracameral antibiotics during cataract surgery to be standard of care, while the U.S. still has no FDA-approved antibiotic to inject. Collagen cross-linking for ectatic disorders is another European invention, popularized in Europe by Theo Seiler and others. The procedure, which involves saturating the cornea with riboflavin, then applying ultraviolet-A light to create covalent bonds between collagen layers, still has no FDA-approved products in the U.S. Clinical studies, such as the CXLUSA study of which my practice is a part, mimic the “standards of care” used in Europe and elsewhere. In fact, our group alone, which has been performing cross-linking at 17 U.S. centers since 2009, is now helping set new standards for this procedure internationally.
Cross-linking is a very simple concept. Over a period of minutes, the cornea is saturated with riboflavin drops. The eye is then treated with a beam of UVA light, and the patient goes home with recovery instructions similar to PRK or LASIK. Depending on whether the corneal epithelium was removed (so-called epi-off CXL) or left in place (epi-on), the healing period is more or less reasonably comfortable, although most patients in both groups have a fair amount of burning on the night of the procedure.
The concept is simple, and the results are fairly consistent across techniques and studies. Stabilization of keratoconus occurs in at least 95% of eyes, depending on whether full saturation of the cornea with riboflavin was achieved. About 60% of eyes have an improvement in their corneal shape and their uncorrected vision. The biggest gift of the procedure, though, is that the vast majority of these patients will never require a corneal transplant.
So why hasn’t the FDA approved this procedure to make it more widely available? After all, in Europe, it’s considered malpractice not to perform cross-linking on patients with progressive ectasia. Simply because the FDA has yet to see a cohesive set of data that meets its requirements to prove safety and efficacy of this procedure. In other words, the jury of thousands of global doctors has voted, but we are waiting for the judge, the FDA, to issue its verdict. I, for one, am eager to see the procedure approved and become more widely available to our many patients in need of treatment. Meanwhile, it’s worthwhile for every eye doctor to become familiar with centers offering investigational procedures, such as those listed on CXLUSA.com, and refer patients with ectasia for treatment.
Disclosure: Hovanesian is an investigator with the CXLUSA study.