Refractive and topographic results after intracorneal ring segment exchange in the treatment of keratoconus

Session Details

Session Title: Keratoconus and Phakic IOLs

Session Date/Time: Monday 12/09/2016 | 16:30-18:30

Paper Time: 17:24

Venue: Hall C4

First Author: : J.Ferreira Mendes PORTUGAL

Co Author(s): :    T. Monteiro   N. Franqueira   F. Faria-Correia              

Abstract Details

Purpose:

To evaluate the refractive and topographic results of patients with keratoconus, previously treated with intracorneal ring segments (ICRS) (Intacs SK® or Ferrara®) and unimproved visual acuity, which were submitted to exchange or explant.

Setting:

Department of Ophthalmology, Hospital de Braga, Portugal

Methods:

Retrospective study of patients who underwent one of the following: explantation of 6,00mm optical zone Intacs SK®-ICRS, and consecutive replacement for a Ferrara®-type; explantation of a single Ferrara®-type ICRS, in a previously treated with double ICRS; explantation of Ferrara®-type ICRS and consecutive replacement for a Ferrara®-type with different characteristics. Inclusion criteria were no improvement of best corrected visual acuity after first surgery, no progression of ectasia after surgery and a minimum follow-up of 12 months. Parameters evaluated were: uncorrected (UDVA) and best corrected (BCVA) visual acuity spherical and cylindrical refractions, topographic parameters, asphericity and aberrometry.

Results:

We included 25 eyes from 25 patients; 9 eyes had Intacs SK exchanged to Ferrara-type ICRS, 14 eyes (with 2 Ferrara type ICRS implanted) had 1 segment explanted and 2 eyes had Ferrara type ICRS exchanged for a different Ferrara segment combination. Six months after ICRS exchange, UDVA improved from 0,10±0,11 to 0,23±0,19 (p=0,10); BCVA improved from 0,35±0,21 to 0,77±0,22 (p<0,01); refractive cylinder reduced from -3,84±1,74 diopters (D) to -2,47±1,78 (p<0,05); mean K1 (p<0,01), K2 (p<0,01) and Kmax (p>0,05) increased; vertical coma improved from -2,11±1,67 to -1,46±1,88 (p<0,01). There was one case of ICRS extrusion due to superficial tunnel.

Conclusions:

ICRS for keratoconus have been described as a safe and effective surgical treatment. The ability to describe the phenotype of the ectasia previous to surgery allows a more precise nomogram of implantation. The surgical technique of ICRS exchange / explant proved to be a safe and effective option if the surgeon has the possibility to describe the phenotype of the ectasia before the first ICRS implantation.

Financial Disclosure:

NONE