Intracorneal ring segment implantation in paracentral keratoconus with non coincident topographic and coma axis: comparison between manual and femtosecond laser surgery

Session Details

Session Title: Cornea: Surgical II

Session Date/Time: Sunday 08/10/2017 | 14:30-16:00

Paper Time: 15:00

Venue: Room 3.6

First Author: : T.Monteiro PORTUGAL

Co Author(s): :    J. Alfonso   F. Faria Correia   N. Franqueira   J. Merayo-Lloves           

Abstract Details

Purpose:

Intracorneal ring segments (ICRS) implantation is a safe and effective surgical procedure for the treatment of keratoconus. The purpose of this study was to compare the visual, refractive and topographic results of ICRS implantation with manual mechanical technique and femtosecond laser-assisted surgery in a specific phenotype of keratoconus: the paracentral keratoconus with no coincident topographic and coma axis.

Setting:

Ophthalmology Department of Hospital de Braga, Portugal / Escola de Ciências da Saúde da Universidade do Minho Fernandez-Vega Ophthalmological Institute, Oviedo, Spain

Methods:

Prospective multicentre study included patients with keratoconus that had ICRS implantation with manual surgery (group 1) or femtosecond laser (group 2). The phenotype of keratoconus (paracentral with non coincident axis) included the thinnest point between 0,8 and 1,6 mm of the pupil center and the coma axis between 30° and 60° of the flat topographic axis. The Ferrara ICRS 150 degrees (AJL, Spain) implanted was centered on the flattest topographic axis. Parameters evaluated at preoperative and 6 months after surgery were: uncorrected (UDVA) and corrected (CDVA) distance visual acuity, manifest refraction, corneal topography and corneal aberrometry with Pentacam (Oculus, Germany).

Results:

The study included 53 eyes in the manual group and 65 eyes in the femtosecond laser group. There were no differences between both groups before surgery regarding Amsler classification, UDVA, BCVA, sphere and Coma. At 6 months, we observed a significant improvement in UCVA, BCVA, refractive cylinder, topographic cylinder, K2, Kmean and Coma in both groups; with no difference between groups after surgery. In group 1 and 2, 46% and 44% gained 2 or more lines of BCVA, respectively. In the manual group, we observed one ICRS extrusion and one intraoperative anterior corneal perforation.

Conclusions:

Ferrara ICRS implantation for the correction of keratoconus in paracentral keratoconus with non coincident topographic and coma axis is a safe and effective technique. Both techniques demonstrated to be safe and effective on terms of visual, refractive and topographic parameters. There were no significant differences demonstrated between both surgical techniques.

Financial Disclosure:

NONE