title: Preliminary results of intrastromal corneal ring segment implantation to treat moderate to severe keratoconus.
abstract: OBJECTIVE
  To present our preliminary experience with implantation of Ferrara intrastromal corneal ring segments (ICRS) in keratoconus patients.
  
  
  METHODS
  Magrabi Eye and Ear Center, Jeddah, Saudi Arabia.
  
  
  METHODS
  Case series.
  
  
  METHODS
  This study comprised patients diagnosed with primary keratoconus who had ICRS implantation. Uncorrected (UDVA) and corrected (CDVA) distance visual acuities were recorded. The change in manifest refraction spherical equivalent (MRSE), mean refractive cylinder, average simulated keratometry (K), and topographic cylinder from preoperatively to 6 months postoperatively was analyzed, and complications were noted. The t test was used to compare 2 independent means and the Wilcoxon signed-rank test, to compare nonparametric data.
  
  
  RESULTS
  By 6 months postoperatively, the CDVA was unchanged in 27% of cases and had improved between 1 line and 6 lines in 64% of cases; 9% of cases lost 1 or 2 lines. There was a decrease in the following mean values: MRSE (-3.60 diopters [D] ± 3.10 [SD] to -2.52 ± 3.10 D; P = .209); refractive cylinder (5.18 ± 2.10 D to 2.90 ± 2.50 D; P = .000); simulated K (51.16 ± 5.60 D to 48.11 ± 3.60 D; P = .000); topographic cylinder (5.30 ± 2.80 D to 3.80 ± 3.20 D; P = .000). For cases with a 24-month follow-up, stability was similar for all parameters. Intraoperative or postoperative complications occurred in 13% of cases; all were managed without clinically significant visual loss.
  
  
  CONCLUSIONS
  Implantation of ICRS resulted in reasonable refractive and visual outcomes in a wide spectrum of keratoconus cases.
  
  
  BACKGROUND
  The author has no financial or proprietary interest in any material or method mentioned. Additional disclosure is found in the footnotes.
authors: Ophthalmology Department, Faculty of Medicine, Ain Shams University, Cairo, Egypt. islammhamdi@hotmail.com
authors: Islam M
authors: IM
authors: Hamdi