BLOG: Study shows cross-linking beneficial in adolescents, young adults
Although keratoconus can present at any age, most cases present between puberty and age 40 years.
In a recent study, Solin Saleh, MD, and Edward Manche, MD, evaluated the effects of corneal cross-linking in a population of patients from this typical onset age group. They demonstrated that cross-linking stabilizes and sometimes improves vision and corneal parameters in pediatric and young adult patients with progressive keratoconus.
The study, which was presented at the American Society of Cataract and Refractive Surgery meeting and published in the journal Cornea, enrolled 86 eyes of 71 consecutive patients aged 12 to 22 years who were treated with iLink epi-off cross-linking (Glaukos) and followed for 2 years. All the eyes in this study had a 1 D or greater increase in maximum keratometry (Kmax) over the previous 12 months.
Young people are at higher risk of rapid progression, severe keratoconus requiring corneal transplantation, and graft rejection, so this is an important population to study. There is some evidence that younger age may be a risk factor for continued progression even after cross-linking because of the aggressive nature of keratoconus that manifests at a young age. In the Manche study, 86.2% of eyes remained stable or had a reduction in Kmax during the 2-year follow-up. At 12 months, mean Kmax was –0.8 D, with further flattening to –1.3 D at 24 months. There was a trend showing improved best corrected visual acuity at 12 months, although this outcome was not statistically significant.
Of interest to those who might be worried about performing cross-linking in younger patients, there were no serious adverse events. Anterior stromal haze was a common postoperative corneal finding, but haze had resolved by the last follow-up examination in all but two eyes and was not visually significant in either of those eyes. Two eyes had persistent epithelial defects, both of which resolved.
Epi-off cross-linking was well tolerated in the study population even in patients as young as 12 years old, without the need for sedation or general anesthesia. I have found this to be the case, as well, and typically perform cross-linking in my office with only topical anesthesia. Most adolescents can handle the procedure with some coaching, which helps us to avoid putting them under general anesthesia for an hour or more.
This is encouraging data for corneal surgeons, referring optometrists and parents. I would like to see even longer follow-up of adolescent and young adult patients treated in the U.S. with our current protocols. To me, this is the population I most want to focus on treating because I know that treatment can potentially help them avoid a lifetime of problems, ranging from frequently changing prescriptions to the need for more complex specialty lens designs or a penetrating keratoplasty. In countries where cross-linking has been approved for a longer time, we have seen the rate of PK decline. While PK is often a sight-restoring procedure, I am hoping that in the near future I won’t have to perform it for patients with keratoconus.
In young people with keratoconus, it is important to also treat comorbidities such as vernal conjunctivitis and counsel them not to rub their eyes.
I encourage colleagues to share studies like the ones discussed here with parents of young patients with keratoconus and with their referral networks.
References:
- Barbisan PRT, et al. Cornea. 2020;doi:10.1097/ICO.0000000000002130.
- Buzzonetti L, et al. Cornea. 2020;doi:10.1097/ICO.0000000000002420.
- Bykhovskaya Y, et al. Eye Vis (Lond). 2016;doi:10.1186/s40662-016-0047-5.
- Godefrooij DA, et al. Acta Ophthalmol. 2016;doi:10.1111/aos.13095.
- Reeves SW, et al. Am J Ophthalmol. 2005;doi:10.1016/j.ajo.2005.05.029.
- Saleh S, et al. Cornea. 2022;doi:10.1097/ICO.0000000000002730.
- Valdez-García, JE, et al. Rev Mex Oftalmol. 2014;doi:10.1016/j.mexoft.2014.03.002.
- Vanathi M, et al. Surv Ophthalmol. 2009;doi:10.1016/j.survophthal.2008.12.011.
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