Review of version 3 nomogram for non-penetrating femtosecond laser intrastromal astigmatic keratotomy during femtosecond laser-assisted cataract surgery

Session Details

Session Title: Challenge of Astigmatism Correction

Session Date/Time: Sunday 14/09/2014 | 17:00-18:30

Paper Time: 17:54

Venue: Capital Hall A

First Author: : N.Lau UK

Co Author(s): :    J. Stevens   A. Day           

Abstract Details

Purpose:

To review the precision of a nomogram created for non-penetrating intrastromal astigmatic keratotomy using femtosecond laser during femtosecond laser assisted cataract surgery

Setting:

Moorfields Eye Hospital, London United Kingdom

Methods:

Eighty eyes with corneal astigmatism underwent femtosecond laser-assisted cataract surgery with concurrent correction of astigmatism using paired symmetrical non-penetrating femtosecond laser intrastromal astigmatic keratotomy (FSAK) with in a single surgeon practice. FSAK was created simultaneously as laser capsulotomy and lens conditioning. FSAK incisions were created at between 20% to 80% depth from the anterior corneal surface. All treatments were performed using an 8.0 mm optical zone with limbal centration. Follow up was performed one month and at six months. Using preoperative and postoperative topography and refractive data, a version 3 nomogram has been refined using multiple regression analysis.

Results:

The mean vector magnitude using nomogram v1 was 60% of intended and increased to 82% of intended with v2 and with this series of 80 eyes is 87%. The main source of residual cylinder was angle error, highlighting the importance of alignment. The nomogram takes into account cylinder magnitude, age and angle of cylinder.

Conclusions:

Catalys femtosecond laser non-penetrating intrastromal astigmatic keratotomy was able to reduce corneal cylinder during femtosecond laser-assisted cataract surgery. A nomogram has been created from our data to enhance predictability and accuracy of this treatment.

Financial Interest:

One or more of the authors... gains financially from product or procedure presented, One or more of the authors... receives consulting fees, retainer, or contract payments from a company producing, developing or supplying the product or procedure presented