Ferrara intracorneal ring segments for keratoconus.
OBJECTIVE
To assess the outcome of Ferrara intracorneal ring segments for keratoconus.


METHODS
Private practice and university hospital, Porto Alegre, Brazil.


METHODS
In this retrospective noncomparative interventional case series, 51 keratoconus eyes of 47 patients that had Ferrara intracorneal ring segment implantation were reviewed. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), central corneal curvature, corneal astigmatism, surface regularity index, surface asymmetry index, and complications were analyzed.


RESULTS
At a mean follow-up of 13.0 months +/- 8.7 (SD), the BSCVA improved in 86.4% of eyes, was unchanged in 1.9%, and worsened in 11.7%. The UCVA improved in 86.4% of eyes, was unchanged in 7.8%, and worsened in 5.8%. The mean spherical equivalent (SE) was reduced from -6.08 +/- 5.01 diopters (D) to -4.55 +/- 5.71 D and the mean refractive astigmatism, from -3.82 +/- 2.13 D to -2.16 +/- 2.07 D. The mean central corneal curvature was reduced from 48.76 +/- 3.97 D to 43.17 +/- 4.79 D. Eyes with central keratoconus had statistically significantly better results than eyes with inferior keratoconus in topographic astigmatism, SE, and refraction cylinder. Penetrating keratoplasty was avoided in 38 eyes (74.5%) during the follow-up. Intracorneal ring segment decentration occurred in 2 eyes (3.9%), segment extrusion in 10 eyes (19.6%), bacterial keratitis in 1 eye (1.9%) with segment extrusion, and a disciform keratitis in 1 eye (1.9%).


CONCLUSIONS
Implantation of Ferrara intracorneal ring segments in patients with keratoconus was a safe and reversible procedure that led to stable results and avoided or delayed PKP in many cases.
Kwitko
Sérgio
S
Department of Ophthalmology, Hospital de Clínicas de Porto Alegre, Avenida Nilo Peçanha, 7241-401 Porto Alegre-RS, Brazil. Kwitko@ez-poa.com.br
Severo
Nórton Souto
NS
D001251:Astigmatism; D001672:Biocompatible Materials; D003319:Corneal Stroma / Q000601:surgery*; D019781:Corneal Topography; D006801:Humans; D007431:Intraoperative Complications; D007640:Keratoconus / Q000601:surgery*; D019904:Polymethyl Methacrylate; D011183:Postoperative Complications; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D012189:Retrospective Studies; D012449:Safety; D014792:Visual Acuity
D001672:Biocompatible Materials; D019904:Polymethyl Methacrylate