Digitized analysis of excimer laser centration: clinical comparison between two lasers

Session Details

Session Title: Photoablation, Cross-Linking and Intracorneal Ring Segment

Session Date/Time: Monday 07/09/2015 | 08:00-10:30

Paper Time: 10:00

Venue: Room 16

First Author: : G.Asimellis GREECE

Co Author(s): :    A. Kanellopoulos                    

Abstract Details

Purpose:

To objectively define the effective centration of myopic LASIK ablation pattern, by analysis between the achieved versus planned excimer laser ablation pattern, and compare centration results from two different generations of an excimer laser system.

Setting:

LaserVision.gr Clinical and Research Eye Institute, Greece

Methods:

Evaluation of 280 eyes subjected to myopic LASIK. Digital image analysis was performed on Scheimpflug sagittal curvature maps (difference of pre-operative to post-operative).Centration was assessed via proprietary-software digital analysis of the coordinate displacement between the achieved ablation geometric center and the planned ablation center, which was the corneal vertex. Results from two different excimer laser generations (Group-A, EyeQ 400 and Group-B, EX500), both platforms of Alcon/WaveLight were compared.

Results:

Average radial displacement in group-A was on average 360±220 μm (range 0 to 1,030 μm), while in group-B 120±110 μm (range 0 to 580 μm). When comparing percentage of eyes with displacement more than 300 μm, in group-A the corresponding percentage was 52% while in group-B it was 4%, respectively.

Conclusions:

We introduce this novel, objective technique for laser refractive surgeon evaluation that may point out significant outcome measures not currently used in standard metrics of refractive laser efficiency. Displacement of ablation pattern may depend on the laser platform. The dramatic improvement in the efficiency of centration indicates that newer generation excimer laser with faster eye tracking and active centration control appear to achieve a significantly more accurate centration of myopic ablation patterns.

Financial Interest:

One of the authors travel has been funded, fully or partially, by a company producing, developing or supplying the product or procedure presented