Recent advances in the treatment of corneal ectasia with intrastromal corneal ring segments

Purpose of review: To review the recent advances and reported outcomes in the use of intrastromal corneal ring segments (ICRS) for the treatment of corneal ectasia. Recent findings: ICRS are a well-tolerated and effective treatment for patients with corneal ectasia, particularly keratoconus, offering long-term improvement in visual, refractive, and keratometric measures. ICRS do not consistently decrease corneal aberrations. Patients with mild-to-moderate keratoconus, known to have less predictable outcomes with ICRS, may be better selected and treated with the use of customized nomograms, accounting for factors such as internal astigmatism. Corneal collagen cross-linking performed after ICRS implantation is an important complementary treatment in preventing the progression of ectasia, whereas subsequent treatment with either photorefractive keratectomy or toric intraocular lens implantation offers a significantly improved visual and refractive result. Summary: ICRS are an important component to the treatment of corneal ectasia. Knowledge of outcomes among specific groups of patients should improve treatment planning and nomograms. Combined treatments with ICRS allow for notable improvements in corneal stability and refractive error, in addition to the improvement in irregular astigmatism seen with ICRS.