Intrastromal Corneal Ring Segments and Keratoconus Progression: A Case Series Study.

Objective: To assess keratoconus (KC) progression following the implant of intrastromal corneal ring segments (ICRSs) in young patients.

Materials and methods: Retrospective, longitudinal, observational, controlled nonrandomized case series study. Keratoconus patients aged 25 years or younger who underwent uneventful ICRS surgery and completed at least 3 years of follow-up were enrolled. Controls were of similar age and treatment-naive patients with KC. The following Pentacam imaging (Oculus, Wetzlar, Germany) data were analyzed: keratometric (maximum, in-flattest meridian, in-steepest meridian, and mean), aberrometric (higher-order aberrations and coma), pachymetric (thinnest corneal thickness), and elevation (maximum posterior elevation). The main outcome measure was KC progression.

Results: The study sample comprised 20 eyes of 18 cases (age 20.20 ± 3.70 years, nine right eyes, 14 male patients) and 30 eyes of 24 controls (age 20.80 ± 3.20 years, 15 right eyes, 21 male patients). The mean follow-up duration was 4.90 ± 1.70 years (range 3-8 years) for cases and 4.50 ± 1.40 years (range 3-8 years) for controls. Four cases and two controls met criteria for KC progression.

Conclusions: Intrastromal corneal ring segments did not have significant impact on KC progression in the cohort.