To say that the last couple of years have seen great changes in the United States would be something of an understatement: One could have substituted years for months, months for weeks, weeks for days, and that statement would have held true. While most in the layman community would focus on the political and historical aspects of that statement, we should also focus on the medical implications.
This goes far beyond the practice of general medicine and the creation of COVID-19 vaccines, as there have also been considerable developments in ophthalmology. We are all familiar with anti-VEGF therapy’s explosion in popularity, while advances in intraocular lenses (IOLs) are offering improved vision for patients. While anti-VEGFs and IOLs are par for the course in the U.S., some developments from abroad are only now beginning to make serious headway in the world’s largest economy.
Corneal cross-linking (CXL), specifically for the treatment and stabilization of keratoconus, is one such technique. It is a minimally invasive procedure that uses ultraviolet light and eye drops in order to strengthen the collagen fibers in the cornea.1 According to the Kellogg Eye Center at the University of Michigan, this technique has been safely practiced outside of the U.S. for over a decade — but it has only recently made inroads into the States.
Conquering Those Disc-Shaped Corneas
Keratoconus is a non-inflammatory eye condition where the healthy dome-shaped clear cornea progressively thins, causing a cone-like bulge to develop. This eventually impairs the ability of the eye to focus properly, causing diminished vision quality that can be difficult to detect in the early stages of the condition. Keratoconus affects around one in every 450 individuals and is more common in non-Caucasian populations.2
Using CXL to treat keratoconus is a major development for patients as there were no surgical options previously available. It is minimally invasive, takes around an hour to perform, and causes little to no discomfort. There are risks of course, as there are for any surgical procedure; these may include epithelial haze, corneal epithelial defect and delayed epithelial healing.
According to available peer reviewed research, using CXL to treat keratoconus is safe and effective. According to one study by a group of researchers from the Eye Center at the University of Freiburg Medical Center in Dortmund, Germany, cross-linking is a reliable steed to be “the first available treatment for keratoconus that can improve the natural course of the disease.”3. The researchers cited their finding that randomized, controlled trials have shown that cross-linking prevents the progression of keratoconus to a statistically significant extent, as determined by measurement of topographic parameters.
The efficacy of the treatment was also further investigated in a number studies that also offered a deeper examination of the treatments safety. For example, Safety and Efficacy of Corneal Cross-linking in Pediatric Patients with Keratoconus and Vernal Keratoconjunctivitis was carried out by an international team of doctors, primarily located in Riyadh, Saudi Arabia, and also at Johns Hopkins Hospital in Baltimore, Maryland, USA. Their aim was to determine the safety and efficacy of corneal collagen cross-linking for keratoconus in pediatric patients with and without vernal keratoconjunctivitis (VKC).
All the Cool Kids Are into Keratoconus
They examined 89 eyes of 58 patients under 18-years-old that underwent corneal collagen cross-linking for progressive keratoconus. When comparing pretreatment patients to the 2-year follow-up, there were no statistically significant changes in mean steep or flat keratometry, corneal thickness, and uncorrected visual acuity or best spectacle-corrected visual acuity in either group.4 This led the researchers to conclude that cross-linking appears to be as safe and effective in pediatric patients with vernal keratoconjunctivitis as in those without, with similar outcomes, adverse events, and progression of keratoconus after treatment.
CXL for keratoconus is therefore becoming an increasingly used and reliable method of surgical intervention. It is likely that its international popularity among ophthalmology professionals will improve in tandem with increased uptake in the U.S. This is a key development worth observing in the ophthalmology industry over the coming 12 months.
1. The Kellogg Eye Center at the University of Michigan. Corneal Cross-Linking (Collagen Cross-Linking). Available at https://www.umkelloggeye.org/conditions-treatments/corneal-cross-linking-collagen-cross-linkin. Accessed on January 10, 2021.
2. The Moorfields Eye Hospital. Keratoconus. Available at https://www.moorfields.nhs.uk/condition/keratoconus. Accessed on January 10, 2021.
3. Maier P, Reinhard T & Kohlhaas M. Corneal Collagen Cross-Linking in the Stabilization of Keratoconus. Deutsches Ärzteblatt International. 10.3238/arztebl.2019.0184.
4. Alrobaian M, Elsayed M, Khalid Alotaibi A et al. Safety and Efficacy of Corneal Cross-linking in Pediatric Patients with Keratoconus and Vernal Keratoconjunctivitis. Middle East-African Journal of Ophthalmology. 10.4103/meajo.MEAJO_240_18.