Corneal Collagen Cross-Linking for Keratoconus: Systematic Review

Area of Science:

• Ophthalmology
• Corneal Surgery
• Regenerative Medicine

Background:

• Keratoconus is a progressive corneal ectasia leading to vision impairment.
• Current treatments aim to halt disease progression and improve visual acuity.
• Collagen cross-linking (CXL) is a therapeutic option for keratoconus.

Purpose of the Study:

• To systematically review randomized controlled trials (RCTs) evaluating the efficacy of CXL for keratoconus.
• To compare CXL treatment outcomes to a no-treatment control group one year post-intervention.
• To assess key visual and refractive parameters following CXL treatment.

Main Methods:

• Systematic review of five RCTs involving 289 eyes.
• Data extraction and quality appraisal by two independent authors.
• Comparison of changes in maximum keratometry, corneal thickness, visual acuity, and refraction between CXL and control groups.

Main Results:

• A significant difference in best spectacle-corrected visual acuity (BSCVA) changes was observed between groups.
• No statistically significant differences were found in corneal thickness or cylindrical refraction.
• Meta-analysis was not performed for Kmax, UCVA, and SE refraction due to high heterogeneity (I² > 50%).

Conclusions:

• CXL may be effective in halting keratoconus progression for one year under specific conditions.
• Limited evidence exists due to significant heterogeneity and a paucity of RCTs.
• Further high-quality RCTs are needed to confirm CXL efficacy and long-term outcomes.