Posters

Topography changes after implantation of Ferrrara intracorneal ring segment in keratoconic eyes: 1 year results

Poster Details

First Author: A.Hashem SAUDI ARABIA

Co Author(s):                        

Abstract Details

Purpose:

To report the topographic changes after the implantation of Ferrara intrcorneal ring segment in keratoconic eyes.

Setting:

Cornea and Refractive surgery Unit, Magrabi eye center, Jeddah, Saudi Arabia.

Methods:

: Retrospective analysis of topography exams of 135 consecutive keratoconic eyes who received Ferrrara ICRS in the period between Januarys to September 2011. Those who had a valid preoperative topography exam and any valid postoperative exam at 3 or 6 or 12 months post operatively were enrolled. Examinations were performed using the NIDEK Optical Path Difference (OPD)-Scan II and analyzed using OPD-Station software. Data retrieved included Keratometric values, Zernike coefficients (Z12), point spread function (PSF), modulation transfer function (MTF) and High order root mean square (HO RMS). The chosen maps were averaged and imported to data analysis program (Datagraph).

Results:

Eighty nine eyes were enrolled, divided into 2 groups, group 1 (1 segment, 50 eyes) and group 2 (2 segments, 39 eyes). At 1 year, Average K has decreased by 1.0 and 3.4 diopters in group 1 &2 respectively (P<0.05). In group 1: HO RMS increased from 1.5 to 1.6µm (P>0.05), Spherical aberration (Z12) increased from 0.18 to 0.49µm (P<0.05), HO MTF and PSF did increase but statistically insignificant (P > 0.05). In group 2, HO RMS increased from 1.9 to 2.1µm (P<0.05), Spherical aberration (Z12) increased from 0.4 to 0.5µm (P<0.05), HO MRS and PSF significantly increased (P<0.05).

Conclusions:

Ferrara ICRS lower the K values both with 1 or 2 segments. Implantation of 1 ferrara segment has no statistically significant effect on HO RMS, PSF or HO MTF but did significantly increase Spherical aberration. Implantation of 2 ferrara segments significantly increases the HO RMS and spherical aberrations although it significantly improves the HO MTF and the PSF yet remained significantly far from the normal values. No finencial interest in any of the materials mentioned in this study.

Financial Disclosure:

NONE