International Journal of Keratoconus and Ectatic Corneal Diseases

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VOLUME 1 , ISSUE 1 ( January-April, 2012 ) > List of Articles


Predictors of Clinical Outcomes after Intrastromal Corneal Ring Segments Implantation

Leonardo Torquetti

Citation Information : Torquetti L. Predictors of Clinical Outcomes after Intrastromal Corneal Ring Segments Implantation. Int J Kerat Ect Cor Dis 2012; 1 (1):26-30.

DOI: 10.5005/jp-journals-10025-1005

Published Online: 01-12-2013

Copyright Statement:  Copyright © 2012; The Author(s).



To evaluate the influence of age and severity of keratoconus in the clinical outcomes of implantation of Ferrara intrastromal corneal ring segments (ICRS).


A total of 1,073 eyes of 810 patients, consecutively operated from January 2006 to July 2008, were evaluated. Two independent analysis were made according to the age of patients and keratoconus staging. Four groups were created according to the age of patients: < 20 years old, 20 to 30, 30 to 40 and >40 years old. The patients were also evaluated according to the keratoconus stage (I to IV). The outcome analysis included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), keratometry (K), asphericity (Q), corneal volume (CV) and pachymetry. All patients were evaluated using the Pentacam.


The postoperative increase in UDVA and CDVA was statistically significant in all groups (p < 0.05). The magnitude of improvement of CDVA was larger for patients between 21 and 30-year-old (CDVA = 20/40) and patients with keratoconus grade I (CDVA = 20/35) (p < 0.05). There was a statistically significant increase in CV and pachymetry postoperatively in all groups. The keratometry (3.95D) and asphericity (–0.77) reduction were larger in patients younger than 20-year-old and in patients with keratoconus grade IV (p < 0.05).


The best clinical outcomes are seen in patients between 20 and 30-year-old and initial cases of keratoconus (grade I). The more advanced the keratoconus, the larger magnitude of K and Q reduction after ICRS implantation.

How to cite this article

Torquetti L, Ferrara G, Ferrara P. Predictors of Clinical Outcomes after Intrastromal Corneal Ring Segments Implantation. Int J Keratoco Ectatic Corneal Dis 2012;1(1):26-30.

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