Refractive and topographic results after exchange of Intacs SK for Ferrara intrastromal corneal ring segments after unsuccessful implantation for keratoconus correction
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Tiago Pacheco Teixeira Monteiro [1] ; José Carlos Ferreira Mendes [1] ; Fernando Faria Correia [1] ; Nuno Franqueira [1] ; Fernando Vaz [1]
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[1] Hospital Braga
Hospital Braga
Braga (São José de São Lázaro), Portugal
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- Localización: Journal of Emmetropia: Journal of Cataract, Refractive and Corneal Surgery, ISSN-e 2171-4703, Vol. 7, Nº. 3, 2016, págs. 159-165
- Idioma: inglés
- Texto completo no disponible (Saber más ...)
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Resumen
In the past, the main goal of intrastromal corneal ring segment (ICRS) implantation was to reduce keratometry. Current treatment nomograms based on classifi cation of the ectasia phenotype aim to provide both therapeutic and refractive correction.
We present the case of a 39-year-old woman diagnosed in 2011 with keratoconus in both eyes, with low best spectacle-corrected distance visual acuity (BCVA) (3/10 Snellen decimal) in the left eye and contact lens intolerance. After surgical implantation of two symmetric 300 μm Intacs SK ICRS (Addition Technology, USA) based on the Amsler-Krumeich classifi cation, BCVA was 2/10 despite a reduction in mean and maximum keratometry; topographic astigmatism and vertical coma (Z₃ˉ¹) remained unchanged. Two years later, both Intacs SK ICRS were removed and a single Ferrara ICRS with 150° arc length and 200 μm thick segment was implanted. One year later, BCVA improved to 8/10, with significant reduction in both corneal astigmatism and vertical coma.
In patients unsuccessfully treated with ICRS, explantation or exchange for a Ferrara type-ICRS based on the ectasia phenotype was found to be safe and effective.
