Avedro’s chief medical officer, Rajesh K. Rajpal, MD, said 2016 marked the first US Food and Drug Administration approval of a collagen cross-linking (CXL) device, Avedro’s Photrexa Viscous, Photrexa, and KXL system.
“Globally, there have been more than 140,000 cross-linking procedures performed,” Dr. Rajpal said. “In the US, our system is approved for progressive keratoconus and post-refractive corneal ectasia.” Outside the US, however, CXL is performed with “accelerated technology” and in combination with LASIK, photorefractive keratectomy (PRK), and the small incision lenticule extraction (SMILE) procedures.
Avedro is ramping up its US sales force, and already has 42 international distributors. “Avedro boasts an experienced management team, and we are a global commercial enterprise,” Dr. Rajpal stated.
“PiXL is the future of refractive CXL,” he said. PiXL – photorefractive instrastomal cross-linking – is best described as ultraviolet A patterning applied to the center (myopia), midperiphery (hyperopia), or a bowtie-shaped region (astigmatism) of a riboflavin-soaked cornea, and already has the CE mark as a non-invasive refractive procedure.
“The goal is to induce focal stiffening in the cross-linked regions, resulting in ‘bulging’ of the cornea in untreated regions in response to normal intraocular pressure,” Dr. Rajpal explained. PiXL is “the perfect treatment” for low myopes, he added, and the market potential is enormous.
Within the US, there are 45 million contact lens wearers, 7.6 million of whom are between 18 and 44 years old, with mild myopia (< –2.75 D). “This is our target PiXL market,” Dr. Rajpal said, adding PiXL could potentially be 10 times the LASIK market.
“These are people who don’t want to consider LASIK because it’s too invasive,” he said. “These patients are not contact lens intolerant, but that doesn’t mean they want to stay in their contacts, either.”
H. Burkhard Dick, MD, and Matthias Elling, MD (Ruhr University, Bochum, Germany) enrolled 40 eyes with mild myopia to evaluate the safety and efficacy of the KXL II system in PiXL procedures, Dr. Rajpal said.
“The treatment effect of about 1.4 D was achieved in the high dose (15 J) and the effects were stable at six months; the low dose (10 J) treatment effect was about 1.0 D, and that was also stable at six months,” he said, noting the European study used an epi-off technique to deliver the riboflavin.
In Singapore, Julian Theng, MD, and Lim Wee Kiak, MD, have enrolled 14 eyes with low myopia (< –2.0 D) to transepithelial PiXL; the average manifest refraction spherical equivalent reduction out to nine months is 0.75 D.
Other studies underway include PiXL with oxygen for the treatment of low myopia, and Dr. Rajpal believes PiXL may be able to address astigmatism, presbyopia, and post-IOL (intraocular lens) enhancements in the future.
Rajesh K. Rajpal, MD
Raj Rajpal, MD is a board certified ophthalmologist who has established an internationally recognized reputation as an expert in the fields of corneal, cataract, and refractive surgery.