Corneal crosslinking (CXL) is still relatively new in the United States, having only gained FDA approval in 2016, with new techniques continuing to enter the market. Researchers from Canada recently reported that while the efficacy of transepithelial, or “epi-on,” CXL remains inferior to the standard epi-off approach for corneal ectasia, this technique may be significantly safer.

The paper, published in Ophthalmology, reviewed 12 recently published studies encompassing 966 eyes enrolled in randomized controlled trials that compared both CXL techniques. The primary outcome was the change in the maximum keratometry value (K) at 12 months following CXL. Secondary outcomes included topographic, visual and safety results.

The investigators reported a significant difference in K change between the groups at 12 months and at the longest follow-up after treatment. Still, they didn’t find a significant difference between the two groups in uncorrected distance visual acuity or corrected distance visual acuity.

They also noted that epi-on CXL was associated with significantly fewer complications, although it was linked to an increased rate of disease progression at 12 months after treatment.

Nath S, Shen C, Koziarz A, et al. Transepithelial versus epithelium-off corneal collagen cross-linking for corneal ectasia: protocol for a systematic review, meta-analysis and trial sequential analysis of randomised controlled trials. BMJ Open. 2019;9(5):e025728.