Randomised controlled trial comparing intrastromal femtosecond laser astigmatic keratotomies to limbal relaxing incisions for the management of corneal astigmatism at the time of cataract surgery: interim results

Session Details

Session Title: Femtolaser-Assisted Cataract Surgery (FLACS) II

Session Date/Time: Monday 09/10/2017 | 08:30-10:30

Paper Time: 09:16

Venue: Room 4.4

First Author: : V.Wagh UK

Co Author(s): :    H. Roberts   I. Mullens   D. O'Brart              

Abstract Details

Purpose:

To compare the effects of manual limbal relaxing incisions (LRIs) to non-penetrating femtosecond laser intrastromal astigmatic keratotomies (FS-AKs) in the management of corneal astigmatism at the time of cataract surgery.

Setting:

St Thomas’ Hospital, London, UK

Methods:

Patients undergoing cataract surgery were randomised to conventional phacoemulsification surgery or femtosecond laser assisted cataract surgery. All patients with corneal astigmatism greater than one dioptre (D) were offered LRI or FS-AK as appropriate which was performed at the time of cataract surgery. Calculations were performed using the Donnenfeld nomogram or the Stevens nomogram respectively. LRIs were performed with a Mendes gauge and a 600micron blade; FS-AKs were performed using a LenSx femtosecond laser (Alcon Inc). Topography was measured by Scheimpflug imaging (Pentacam) prior to surgery and 3 weeks post op. Vector analysis was performed using the Alpins method.

Results:

20/85 (24%) and 20/93 (22%) patients received LRI or FS-AK respectively. Mean target induced astigmatism 1.36 D ± 0.40 in the FS-AK group and was 1.51 D ±0.50 in the LRI group. After treatment, residual astigmatism was 0.81D±0.56 and 1.35D±0.64 in the FS-AK and LRI groups respectively (p=0.007). Surgically induced astigmatism was 0.55D±0.49 for FS-AK and 0.16±0.55 for LRI (p=0.02). Post operatively, remaining corneal cylinder was less than 0.5D in 40% of FS-AKs and 10% of LRIs, less than 1D in 65% and 35%, less than 1.5D in 85% and 55% respectively.

Conclusions:

In the treatment of patients undergoing cataract surgery with corneal astigmatism greater than 1 D, both LRIs and AKs tended towards undercorrection of corneal astigmatism. However patients treated with FS-AKs had significantly reduced astigmatism at 3 weeks post treatment compared to those treated with LRIs.

Financial Disclosure:

research is funded, fully or partially, by a company producing, developing or supplying the product or procedure presented