Keratoconus is a progressive asymmetric disorder associated with structural changes in corneal collagen organization. The disease usually manifests in the second decade of life, resulting in corneal thinning that can lead to irregular astigmatism, corneal scarring, and poor vision. Because the disease is more aggressive in pediatric populations, management and treatment should be pursued immediately (Kankariya et al, 2013).

CXL in Pediatrics

Corneal cross-linking (CXL) has been a treatment option for keratoconus in many countries since 2003; it was approved by the U.S. Food and Drug Administration (FDA) in 2016 for treatment of progressive keratoconus in patients aged 14 years and older. The FDA standard protocol requires mechanical debridement of the corneal epithelium under topical anesthesia. Following debridement, one drop of riboflavin 0.1% solution is administered to the exposed stroma every two minutes for 30 minutes, followed by exposure to UV-A light (370nm ± 5nm wavelength, 5.4 J/cm² irradiance), with instillation of the riboflavin solution every two minutes for an additional 30 minutes (Perez-Straziota et al, 2018).

The standard epithelium-off protocol performed in children stabilized the disease process for up to two years (Padmanabhan et al, 2017). Improvement of corrected distance vision and a decrease in maximum keratometry readings also were reported (Padmanabhan et al, 2017).

Scleral Lenses Post-CXL

Scleral lenses have many therapeutic benefits for children. Compared to soft lens designs, the rigid material is easier to handle, and sclerals have greater initial comfort, are stable, and have excellent optics. Sclerals are indicated when it is difficult to achieve an acceptable pediatric fit or sufficient vision with other lenses (Severinksy and Lenhart, 2021).

Scleral lenses are a great option for fitting pediatric keratoconus after CXL. Sclerals can be fitted as soon as two-to-three weeks after CXL, because they vault completely over the cornea with no contact to the healing tissue (Michaud and Breton, 2018). Because CXL causes epithelial disruption, stromal hazing, and edema, visual acuity is initially reduced compared to baseline, but it improves during the next 12-to-24 months (Perez-Straziota et al, 2018).

Consider a 14-year-old Hispanic male diagnosed with progressive keratoconus at age 13. At age 14, he underwent CXL in both eyes, and medical contact lenses were indicated to improve vision after the procedure. Before CXL, he had tried corneal GPs without success due to poor comfort and constant dislodgement of the lenses. One month after CXL, he was fitted into sclerals that improved his vision to 20/25 OD and 20/40 OS. Additionally, he reported good comfort and was able to apply and remove the lenses successfully (Figure 1). With scleral lens wear, his disease did not progress in the two years post-op.

Summary

Progression of keratoconus is attenuated by CXL. Following CXL, pediatric patients need vision correction for irregular astigmatism. Scleral lenses are safe to prescribe even in the peri-operative period, offer positive handling, and often exhibit superior optics for keratoconic eyes. Pediatric patients who have keratoconus are encouraged to undergo CXL, and scleral lenses may help in their healing as well as provide best-corrected vision going forward. CLS

For references, please visit www.clspectrum.com/references and click on document #309.