Evaluation of clear corneal incisions and laser keratotomy on corneal astigmatism in femtosecond laser-assisted cataract surgery

Session Details

Session Title: Interactive Free Paper Session: FLACS

Session Date/Time: Sunday 06/09/2015 | 08:30-10:00

Paper Time: 09:28

Venue: Room 16

First Author: : T.Kohnen GERMANY

Co Author(s): :    F. Loeffler   K. Petermann   M. Boehm   C. Titke   M. Herzog   O. Klaproth     

Abstract Details

Purpose:

To describe the effect of femtosecond laser clear corneal incisions (CCI) and laser astigmatic keratotomy (LK) on the total corneal refractive power (TCRP) using Scheimpflug tomographic measurements.

Setting:

Department of Ophthalmology, Goethe University Frankfurt, Germany.

Methods:

In this prospective study 91 eyes of 55 patients who underwent femtosecond laser assisted cataract surgery from June 2013 to July 2014 were measured with Pentacam HR preoperatively, 1 month and 3 months postoperatively. Before surgery eyes were divided into 3 groups: Group 1 (TCRP ≤ 0.50 D) received a temporal CCI. Group 2 (TCRP 0.51 - 0.75 D) received a CCI on the steep axis and group 3 (TCRP > 0.75 D) had LK based on Wang's et al nomogram. Vector analysis based on the Holladay-Cravy-Koch formula and Alpins' method was used to determine astigmatic changes. Wilcoxon-test was performed.

Results:

Mean surgically induced astigmatism (SIA) after 3 months was 0.28 ± 0.17 D in Group 1. SIA was independent of the axis of TCRP. In Group 2 mean preoperative TCRP was 0.65 ± 0.05 D and declined to 0.48 ± 0.06 D 3 months postoperatively with mean SIA of 0.39 ± 0.25 D. Although mean TCRP in Group 3 was reduced significantly (p = 0.000) with a mean SIA of 0.74 ± 0.32 D, a mean index of success (IOS) of 1.03 ± 0.61 and a mean correction index (CI) of 0.77 ± 0.58 indicate that a moderate undercorrection occurred.

Conclusions:

Femtosecond laser CCI induce minimal astigmatism and laser keratotomy reduces preexisting TCRP. Further research with a larger sample size of eyes is needed to create a new nomogram for femtosecond laser assisted cataract surgery

Financial Interest:

NONE