More advances expected in cross-linking for keratoconus
Lindstrom reports relevant financial disclosures with Avellino, CXLO, Glaukos/Avedro, iVeena, Johnson & Johnson Vision, KeraFlow, Visionary Ventures and Zeiss.
The accompanying cover story summarizes some pioneering activities in collagen cross-linking for keratoconus.
In this commentary, I am going to take a look into the future of CXL and share some of my thoughts. A few may be controversial to some readers. In advance, I will disclose that I consult widely in the field of keratoconus management, including Avellino, CXLO, Glaukos, iVeena, Johnson & Johnson Vision, KeraFlow, Visionary Ventures and Zeiss.
Richard L. Lindstrom
First, the global consensus is that progressive keratoconus should be detected early and treated immediately. I believe that keratoconus is a subset of progressive myopia and that progressive myopia should also be detected early and treated immediately. A decade from now, following an intense public awareness campaign, I see nearly all 5- to 6-year-old myopic children being under the care of an eye care provider. Those with progressive myopia will be treated with behavior modification, specialty contact lenses and spectacles, and topical disease-modifying eye drops. Every eye care provider treating progressive myopia will have access to topography, genetic testing and perhaps axial length measurement diagnostics.
The progressive myope will be followed and treated from age 6 years until stable, perhaps as late as age 26 years or occasionally even older. Inside this large cohort of progressive myopes, we will find the patients with progressive keratoconus, sometimes presenting as early as age 10 to 12 years. The moment topography, pachymetry, family history or genetic testing suggests progressive myopia is converting into progressive keratoconus, we will treat with collagen cross-linking. We will be treating these patients with progressive keratoconus with 20/20 or better best corrected vision and maximum keratometry readings in the 40s in their teens rather than with best corrected vision of 20/40 or worse and maximum keratometry readings in the 50s or 60s at age 30-plus. This will be virtuous for these patients and also the eye care provider, providing another meaningful office-based revenue opportunity.
Second, a few thoughts on how the patient with progressive keratoconus will be treated. The most common CXL treatment will be so-called epithelium-on CXL, eye drops or both sequentially or simultaneously. It is clear epithelium-off CXL is more effective in flattening the cornea, but I believe for many patients, it is more treatment than required. While at 1 year, mean flattening of maximum keratometry is approximately 1.5 D with epithelium-off CXL, and the cornea continues to flatten for 3 years, such an intense treatment may be overkill. Newer epithelium-on CXL techniques with specialized riboflavin stromal loading methods and oxygen supplementation are generating mean maximum keratometry reductions between 0.4 D and 0.8 D at 1 year. In addition, data suggest complications related to corneal epithelial wound healing challenges, corneal haze and loss of best corrected vision are lower with epithelium-on CXL.
While we need more data from across the globe to be sure, in our experience at Minnesota Eye Consultants using the KeraFlow device to load the corneal stroma with riboflavin, we have not found an increase in the number of patients who are treatment failures and require a second treatment as compared to classic epithelium-off CXL. With epi-on CXL, it is routine and humane to treat both eyes in a same-day simultaneous fashion, and the difference in patient experience is similar to the well-known difference between doing a same-day sequential PRK/PTK vs. LASIK or SMILE.
Finally, while I believe we will begin the transition toward epi-on CXL in the U.S. next year if the Glaukos epi-on system is approved by the FDA, we will not stop there. The next disruptive innovation will be CXL with eye drops. This new approach is being pioneered by a U.S. company called iVeena using a patented copper sulfate eye drop with promising offshore pilot data. I see eye drops that can induce CXL as both an independent treatment and also an adjunct to procedural epi-on CXL.
Between treating progressive myopia, progressive keratoconus and progressive presbyopia along with ocular surface disease with eye drops and office-based procedures, the comprehensive ophthalmologist and the comprehensive optometrist will find many more patients in their office-based practices. For the ophthalmologist or the integrated ophthalmology/optometry practice, every year more eye care provider fee-based revenue will be generated in the office practice vs. the operating suite. Yes, for a busy surgical ophthalmology practice, owning equity in an ASC is a strong positive, but with the future trends toward more employee eye care providers, there will be less opportunity for ophthalmologists to own equity in a practice or ASC. For this reason, the growing opportunity to generate meaningful revenues in office-based practice will become ever more important.
The office-based pharmaceutical and procedural management of myopia, keratoconus and presbyopia, as well as astigmatism and hyperopia, represents a great new opportunity in eye care. The prudent eye care practice will carefully evaluate how it might best participate, as the accessible total market is very large for both the practitioner and the industry that supports us.