ICR Offers Refractive and Visual Improvements, But …

The intrastromal corneal ring (ICR) appears to offer refractive and visual improvements, according to a systematic review presented at the 2018 World Ophthalmology Congress in Barcelona. However, the evidence should be considered cautiously given potential methodological bias.

The analysis involved 14 studies evaluating 741 eyes subjected to the procedure. Among the findings:

• Uncorrected visual acuity (UCVA) improved by 0.26 and best corrected visual acuity (BCVA) by 0.052 LogMAR at 6 months.
• Sphere improved by 2.21 diopters and keratometry by 4.02 D within 12 months.
• According to 4 of the studies involving dual therapy, corneal ring implants combined with collagen crosslinking improved UCVA by 0.316 and BCVA by 0.13 LogMAR at 12 months.
• It improved sphere by 3.47D and cylinder by 2.27D.
• Complications included white deposits, epithelial defects, extrusion, decentration, anterior perforation, segment migration, and neovascularization.

The authors found a number of shortcomings in the studies analyzed that were not revealed in their respective methodologies.

Majias J. Effectiveness of intrastromal corneal ring segment implantation in the treatment of adult patients with keratoconus: A systematic review. Poster presented at: 2018 World Ophthalmology Congress; June 16-19, 2018; Barcelona, Spain.