This head-to-head comparison found that corneal crosslinking (CXL) using either a transepithelial approach with iontophoresis (T-ionto CXL) or the standard Dresden protocol provides favorable visual outcomes in patients with progressive keratoconus.
Study design
Thirty-four eyes of 25 participants with progressive keratoconus were randomized to receive T-ionto CXL (22 eyes) or standard CXL (12 eyes).
T-ionto CXL was performed using an iontophoresis device on corneas pretreated with dextran-free 0.1% riboflavin-5-phosphate solution and enhancers, and irradiated at 10 mW/cm2 ultraviolet A for 9 minutes. Standard CXL was performed using the Dresden protocol.
Outcomes
At the 12-month mark, eyes that underwent the Dresden protocol displayed greater improvements in corneal topography readings. On average, Kmax flattened by −0.52 D (P=0.06) in the T-ionto CXL group and −0.82 (P=0.04) in the standard CXL group. The authors also note that participants younger than 24 years in the T-ionto CXL group showed unstable Kmax readings at 12 months.
Overall, T-ionto CXL improved keratometry readings in 80% of cases and decreased myopic defocus in 60% of cases. In contrast, standard CXL improved keratometry in 90% of cases and decreased myopic defocus in 33% of cases. All patients experienced stable or improved visual acuity, although faster visual recovery was noted in T-ionto CXL patients.
No complications occurred in the T-ionto CXL group. In the standard CXL group, 1 eye had sterile corneal infiltrates, which did not affect the final visual acuity.
Limitations
This study is limited by the lack of robust outcome measures for keratoconus progression and response to therapy. Future comparative studies should incorporate more specific monitoring methodologies, larger data sets, and longer follow-up times.
Clinical significance
Despite the faster clinical recovery of visual performance with T-ionto CXL, the authors still recommend standard CXL in patients younger than 24 years of age.
Although too preliminary to replace the gold standard Dresden protocol, T-ionto CXL shows promise. As the field of CXL continues to evolve, it will allow us to not only improve outcomes but also recovery times and safety. What are your thoughts on this technique compared to the gold standard?