Standard cross‐linking protocol versus accelerated and transepithelial cross‐linking protocols for treatment of paediatric keratoconus: a 2‐year comparative study

Abstract

Purpose: To compare the efficacy, safety and stability of standard epithelium-off cross-linking (SCXL) versus accelerated epithelium-off cross-linking (ACXL) and transepithelial epithelium-on cross-linking (TCXL) in the treatment of progressive keratoconus (KC) in children. Methods: This prospective multicentre controlled trial included 271 eyes (136 children) with grade 1-3 progressive KC who were randomized to undergo SCXL (n = 91, as a control group), ACXL (n = 92) or TCXL (n = 88). Uncorrected and corrected distance visual acuity, subjective refraction, pachymetry, keratometry and corneal topography measurements were recorded preoperatively and 6, 12 and 24 months postoperatively. Results: At 1 year, there was no significant difference in uncorrected distance visual acuity, refractive sphere, cylinder, spherical equivalent or Kmax between the ACXL and SCXL groups; however, during year 2, ACXL regressed while SCXL continued to improve. After 2 years, there were significant differences in all visual, refractive and keratometric components between SCXL and both ACXL and TCXL (p < 0.0001) and between ACXL and TCXL (p < 0.0001). KC progressed in 5.4% of patients who had ACXL and 28.4% of those who had TCXL but in none of those who had SCXL. Vernal keratoconjunctivitis was documented in 43.3% of eyes that progressed postoperatively. Conclusion: SCXL was more effective for paediatric KC and achieved greater stability than either ACXL or TCXL, and ACXL was superior to TCXL. SCXL also achieved marked improvement in both myopia and spherical equivalent; however, these refractive outcomes were unpredictable and uncontrollable. TCXL had a 28.4% failure rate within 2 years. SCXL is preferable for management of paediatric KC.

WITHDRAWN: Comparison of Standard Versus Accelerated Epithelium-Off and Transepithelial Corneal Cross-Linking in Pediatric Keratoconus: An Up-to-date Meta-Analysis

“…Similarly, a multi-center trial by Iqbal et al showed that standard epithelium-off was more effective in pediatric keratoconus, attaining great stability as compared to either accelerated or transepithelial CXL. 12 On the other hand, Eissa et al reported that at 12-month follow-up, postoperative mean LogMAR UCVA, BCVA and Kmax of accelerated CXL were statistically less than those of conventional CXL in pediatric keratoconus eyes. 14 The con icting results might result from varied follow-up duration and small sample sizes.…”

“…The follow-up time of each research was ranging from 6 months to 48 months. Two studies were RCTs, 12,14 while the others were CNSs. 13,21−25 Each study compared the UCVA, BCVA, Kmax and CCT of different CXL protocols.…”

“…Meta-analysis about the comparison of epithelium-off versus transepithelial CXL in adult or mixed-age (both adult and children) patients suggests SCXL and TCXL might provide a comparable effect on visual, refractive, pachymetric and endothelial outcomes post-surgery, 11 however in pediatric population such an analysis is still unavailable. Given the publications of new trials and comparative observations for CXL of different protocols in long-term follow-ups, [12][13][14][15][16] an update of summery is necessary. Hence, we conducted a meta-analysis to compare the e cacy of SCXL with ACXL, TCXL and A-TCXL in pediatric keratoconus.…”

<p>Visual and Refractive Long-Term Outcomes Following Standard Cross-Linking in Progressive Keratoconus Management</p>

“…On the other hand, Woo et al43 reported that ACXL has advantages over SCXL regarding biomechanical stability. Iqbal et al44 showed the superiority of SCXL protocol over accelerated and transepithelial protocols.…”

Long-Term Visual, Refractive and Topographic Outcomes of KeraRings Combined with Accelerated Transepithelial Crosslinking for Management of Different Grades of Progressive Keratoconus: A Retrospective Cohort Study

“…The answer is simply related to the time when we operated the studied eyes. Actually, Keratoconus disease is being treated in our localities in Egypt for more than 15 years, and we now have reasonable experience in this field [8,18,29,30,35]. We started the crosslinking procedures in 2009 using SCXL alone that showed the best CXL outcomes ever in halting KCP.…”