International Journal of Keratoconus and Ectatic Corneal Diseases

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


Refractive, Tomographic and Biomechanical Outcomes after Implantation of Ferrara ICRS in Keratoconus Patients

José M Salgado-Borges, Cláudia Costa-Ferreira, Manuel Monteiro, José Guilherme-Monteiro

Citation Information : Salgado-Borges JM, Costa-Ferreira C, Monteiro M, Guilherme-Monteiro J. Refractive, Tomographic and Biomechanical Outcomes after Implantation of Ferrara ICRS in Keratoconus Patients. Int J Kerat Ect Cor Dis 2012; 1 (1):16-21.

DOI: 10.5005/jp-journals-10025-1003

Published Online: 01-12-2013

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



Nowadays, ICRS are a step in the treatment of keratoconus. The purpose of this study was to evaluate the refractive effect and the tomographic and biomechanical parameters in keratoconus patients implanted with Ferrara ICRS, and their stability after 18 months.

Materials and methods

Twenty eyes of 20 keratoconus patients implanted with ICRS were evaluated. The average follow-up was 18 months. UDVA, CDVA, biomicroscopy, tomography (Pentacam) and biomechanics (ORA) of the cornea were evaluated before and after surgery. For the comparison of groups, the Wilcoxon test was used.


The mean UDVA improved from 1.00 to 0.30 and the mean CDVA improved from 0.51 to 0.12; both were statistically significant (p = 0.0001). The average keratometry decreased from 50.7D to 47.5D (p = 0.0003), and the average astigmatism decreased from 5.5D to 3.5D (p = 0.0058). The mean CCT did not change significantly after surgery, but the mean TPP increased from 441.2 to 455.2 µm (p = 0.004). There was a significant reduction in the anterior cornea elevation, both the central (from 16.2-8.8; p = 0.0066) and the minimum (from–43.2 to −57.1; p = 0.0228). No significant change was found for posterior corneal elevation and for biomechanical parameters (hysteresis or CRF).


There was a significant improvement of UDVA and CDVA after ICRS implantation, in keratoconic eyes. There was a significant and stable corneal flattening, and a decrease of the astigmatism. Corneal biomechanic parameters did not change.

How to cite this article

Salgado-Borges JM, Costa-Ferreira C, Monteiro M, Guilherme-Monteiro J, Torquetti L, Ferrara P, Ambrósio R Jr. Refractive, Tomographic and Biomechanical Outcomes after Implantation of Ferrara ICRS in Keratoconus Patients. Int J Keratoco Ectatic Corneal Dis 2012;1(1):16-21.

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  1. Evaluation of corneal topography with Orbscan II in first-degree relatives of patients with keratoconus. Cornea 2008;27:531-34.
  2. Riboflavin/ultraviolet-A- induced collagen crosslinking for the treatment of keratoconus. Am J Ophthalmol 2003;135:620-27.
  3. Crosslinking treatment of progressive keratoconus: New hope. Curr Opin Ophthalmol 2006;17:356-60.
  4. Corneal collagen crosslinking using riboflavin and ultraviolet— a light for keratoconus: One-year analysis using Scheimpflug imaging. J Cataract Refract Surg 2009;35:425-32.
  5. Intrastromal corneal ring: One-year results of first implants in humans: A preliminary nonfunctional eye study. Refract Corneal Surg 1993;9:452-58.
  6. Intrastromal corneal ring segment implantation for ectasia after refractive surgery. J Cataract Refract Surg 2010;36:986-90.
  7. Intracorneal rings for keratoconus and keratectasia. J Cataract Refract Surg 2007;33:1303-14.
  8. Clinical outcomes after implantation of a new intrastromal corneal ring with a 210 degree arc length. J Cataract Refract Surg 2009;35:1604-08.
  9. Corneal tomographic and biomechanical changes after Ferrara intrastromal rings for keratoconus correction. In: Abstracts of the 13th ESCRS Winter Meeting. Rome: ESCRS 2009;30.
  10. Long-term follow-up of Intacs from a single center. J Cataract Refract Surg 2001;27:1456-68.
  11. Implantation of Intacs and a refractive intraocular lens to correct keratoconus. J Cataract Refract Surg 2003;29:832-34.
  12. Ferrara intrastromal corneal rings for the correction of keratoconus. J Cataract Refract Surg 2002;28:1947-51.
  13. Long-term follow-up of intrastromal corneal ring segments in keratoconus. J Cataract Refract Surg 2009;35:1768-73.
  14. Central and peripheral pachymetry measurements according to age using the Pentacam rotating Scheimpflug camera. J Cataract Refract Surg 2007;33: 830-36.
  15. Biomecânica da córnea no ceratocone. Abstract of the 49th Congress of the SPO. Évora, Portugal: SPO 2006, CL17.
  16. Ferrara intracorneal ring segments for keratoconus. J Cataract Refract Surg 2004;30:812-20.
  17. Treating keratoconus with Intacs corneal ring segments. J Refract Surg 2005;21:236-46.
  18. Intacs inserts for treating keratoconus. One-year results. Ophthalmology 2001;108:1409-14.
  19. Intracorneal ring segments for keratoconus correction: A long-term follow-up. J Cataract Refract Surg 2006;32:978-85.
  20. Analysis of results related to good and bad outcomes of Intacs implantation for keratoconus correction. J Cataract Refract Surg 2006;32: 756-61.
  21. Biomechanical and morphological corneal response to placement of intrastromal corneal ring segments for keratoconus. J Cataract Refract Surg 2009;35:1761-67.
  22. Intacs for keratoconus. Ophthalmology 2003;110:1031-40.
  23. One-year results of intrastromal corneal ring segment implantation (KeraRing) using femtosecond laser in patients with keratoconus. Am J Ophthalmol 2008;145:775-79.
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