Corneal Cross-Linking for Paediatric Keratoconus: A Systematic Review and Meta-Analysis

Abstract

All corneal cross-linking techniques attenuated disease progression in patients with pediatric keratoconus for at least one year based on a meta-analysis. A standard and accelerated technique led to marked improvement in visual acuity. We determined the efficacy and safety of corneal cross-linking (CXL) in pediatric keratoconus by conducting a systematic review and meta-analysis. The PubMed and Cochrane databases were searched for relevant studies on the effects of standard, transepithelial, and/or accelerated CXL protocols in patients aged 18 years or younger. Standardized mean differences with 95% confidence intervals were calculated to compare the data collected at baseline and 12 months. The primary outcomes were maximum keratometry (Kmax) and uncorrected visual acuity (UCVA), and the secondary outcomes were the thinnest corneal thickness (TCT), best-corrected visual acuity (BCVA), and manifest refraction spherical equivalent or cylindrical refraction. Our search yielded 7913 publications, of which 26 were included in our systematic review and 21 were included in the meta-analysis. Standard CXL significantly improved the Kmax, UCVA, and BCVA, and significantly decreased the TCT. Accelerated CXL significantly improved UCVA and BCVA. In the transepithelial and accelerated-transepithelial CXL methods, each measurable parameter did not change after treatments. All CXL techniques attenuated disease progression in patients with pediatric keratoconus for at least one year. Standard and accelerated CXL led to marked improvement in visual acuity.

Comparison of Efficacy and Safety Between Standard, Accelerated Epithelium-Off and Transepithelial Corneal Collagen Crosslinking in Pediatric Keratoconus: A Meta-Analysis

“…A meta-analysis pooling data from multiple studies may offer important insights into the comparison of different CXL techniques. Two meta-analyses analyzed children’s data and demonstrated the efficacy of SCXL, ACXL, and TECXL in preventing the progression of keratoconus ( 12 , 14 ) and showed that all CXLs could attenuate the disease progression in the patients with pediatric keratoconus. These two studies were comprehensive, but not comparative for different CXL techniques.…”

“…Meta-analysis of the comparison between epithelium-off and transepithelial CXL in adult patients has suggested that SCXL and TECXL might provide comparable effects on visual and pachymetric outcomes after surgery ( 13 ). A recent meta-analysis of CXL in pediatric patients included 21 studies and determined the efficacy and safety, but did not focus on the comparison between different protocols ( 14 ). Hence, we conducted a meta-analysis to compare the efficacy of SCXL with ACXL and transepithelial CXL in pediatric keratoconus.…”

Corneal Crosslinking: Present and Future

“…To date, 2 meta-analyses have reported CXL outcomes in the pediatric population. Fard et al 45 examined 28 reports totaling 1300 eyes, and Kobashi et al 50 examined 26 studies totaling 1718 eyes. Both reported that CXL is effective in halting the progression of keratoconus in the pediatric population.…”

Controversies in Corneal Collagen Crosslinking: A Review of Investigational Crosslinking Protocols and Its Off-label Application

“…Significant flattening of keratometry values were found during 12 and 24 months follow up in studies conducted by Badawi et al 67 and Shetty et al, 68 respectively. In a metanalysis performed by Kobashi et al, 69 standard, accelerated, transepithelial, and acceleratedtransepithelial crosslinking protocols all led to attenuated disease progression in pediatric keratoconus patients for at least 1 year, with marked improvement in visual acuity noted in standard and accelerated crosslinking protocols. 70,71 However, transepithelial and acceleratedtransepithelial crosslinking techniques resulted in smaller corneal flattening when compared with standard crosslinking, with a success rate of 71.6% in a study conducted by Iqbal et al 72 compared with 94.6% in standard crosslinking.…”