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Intrastromal corneal ring segments: visual outcomes from a large case series
Author(s) -
Ferrara Guilherme,
Torquetti Leonardo,
Ferrara Paulo,
MerayoLloves Jesús
Publication year - 2012
Publication title -
clinical and experimental ophthalmology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.3
H-Index - 74
eISSN - 1442-9071
pISSN - 1442-6404
DOI - 10.1111/j.1442-9071.2011.02698.x
Subject(s) - keratometer , medicine , visual acuity , ophthalmology , cornea , corneal topography , corneal pachymetry
A bstract Background: To evaluate the clinical safety and efficacy of implanted Ferrara intrastromal corneal ring segments in a large sample of patients with ectatic corneal disease. Design: Retrospective, consecutive case series. Samples: A total of 1073 eyes of 810 patients consecutively operated from January 2006 to July 2008 were evaluated. Methods: Two groups were created according to the type of ring implanted: Group 1 – patients implanted with the 160° of arc ring – and Group 2 – patients implanted with the 210° of arc ring. Main Outcome Measures: Uncorrected visual acuity, best‐corrected visual acuity, keratometry, asphericity and pachymetry at the thinnest point of the cornea. All patients were evaluated using a corneal tomography (Pentacam, Oculus, Inc., Lynnwood, WA, USA). Results: For Group 1 patients, uncorrected visual acuity increased to 20/80, best‐corrected visual acuity increased to 20/40, asphericity decreased to −0.35, spherical equivalent decreased to −2.26 D and keratometry decreased to 45.72 D ( P < 0.001 for each compared with preoperative values). For Group 2 patients, uncorrected visual acuity increased to 20/130, best‐corrected visual acuity increased to 20/60, asphericity decreased to −0.56, spherical equivalent decreased to −4.14 D and keratometry decreased to 48.10 D ( P < 0.001 for each compared with preoperative values). The 210° intrastromal corneal ring segments reduced keratometry and asphericity more than the 160° intrastromal corneal ring segments did. The complication rate was 3.82%. Conclusions: Ferrara intrastromal corneal ring segments implantation is safe and effective and has a low complication rate. It can effectively reduce the corneal steepening and improve uncorrected visual acuity and best‐corrected visual acuity in patients with keratoconus.