Femtosecond Laser-Assisted Intrastromal Astigmatic Keratotomy for the Treatment of

Astigmatism Post-Penetrating Keratoplasty: 6- Month Outcomes of a Prospective Interventional

Case Series

World Cornea Congress VII – Electronic Poster

Season Tse Wing Yeung, MBBS, FRANZCO Ronan Conlon, MD; Joshua Teichman, MD, FRCSC; Setareh Ziai, MD, FRCSC;

George Mintsioulis MD, FRCSC; Kashif Baig, MD, MBA, FRCSC The University of Ottawa Eye Institute

Dr. Baig is a consultant for Alcon, Allergan, Bausch & Lomb, Labtician. Dr. Yeung, Dr. Conlon, Dr. Teichman, Dr. Ziai, Dr. Minsioulis have no financial interests in the subject matter of this presentation.

Introduction Visual rehabilitation post-penetrating keratoplasty (PKP) can be

difficult due the the high magnitude of astigmatism (up to 5D), which may not be correctable with glasses or contact lenses (38%)1

A number of corneal techniques have been described to address this problem including astigmatic keratotomy (AK)

The precision and accuracy of arcuate incisions in AK have significantly improved with the incorporation of femtosecond laser technology

Recent case reports have shown that femtosecond laser-assisted intrastromal astigmatic keratotomy (FISAK) is efficacious in the management of astigmatism in PKP patients2 1. Cleary, C et al. (2013) Cornea 32:54-622. Viswanathan, D (2013) JCRS 39:1916-20

Purpose

The purpose of this study is to report the outcomes of the correction of astigmatism with femtosecond laser-assisted intrastromal astigmatic keratotomy (FISAK) in patients with previous PKP

Methods

Prospective non-randomized interventional case series Inclusion criteria:

• Patients who had significant astigmatism following PKP• Complete suture removal at least 1 month prior to the procedure• Contact lens intolerance• Stable refraction

Paired intrastromal arcuate incisions were created with a femtosecond laser (IntraLase™; AMO)

Multiple postoperative visits were scheduled during the 6-month follow up period

Methods

• At each study visit, data as outlined were recorded: uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), slit lamp microscopy, IOP, manifest refraction, corneal topography, and anterior segment OCT

• The primary outcomes of the study were postoperative UCVA and BCVA

• The secondary outcomes were the reduction of refractive and topographic cylinder

• Intra-operative and postoperative complications were also documented

Results - DemographicsAge Eye UCVA BCVA Sphere (D) Cylinder (D) Topographic

Astigmatism (D)

1 24 OS 20/100 20/20 -3.50 4.50 6.2

2 71 OD 20/200 20/30 -11.25 8.00 4.9

3 69 OS 20/60 20/25 -3.00 5.25 4.5

4 40 OD 20/40 20/25 -5.75 5.00 5.1

5 33 OS 20/50 20/15 -5.75 6.00 5.8

6 75 OD 20/150 20/25 -6.50 7.00 7.1

7 69 OD 20/50 20/25 -1.00 5.00 4.3

8 87 OD 20/80 20/25 -6.00 4.00 3.5

9 87 OS 20/150 20/40 -8.25 5.00 5.6

10 55 OS 20/250 20/30 -12.25 8.00 12.0

Results

Ten patients were recruited (M:F = 6:4)

No serious adverse events were reported

At the 6-month follow up: Improvements in both mean UCVA and

mean BCVA were recorded A statistically significant decrease in mean refractive

sphere was observed: -5.67 + 3.00 D -4.33 + 3.44 D (P=0.01)

Results

For mean refractive cylinder: At the 1-month follow-up, mean

refractive cylinder reduced from: 5.52 + 1.27 D 3.55 + 1.90 D (P<0.001)

At the 6-month follow-up, the reduction in mean refractive cylinder continued: 5.52 + 1.27 D 2.67 + 1.61 D (P<0.001)

Results

1 2 3 4 5 6 7 8 9 100.001.002.003.004.005.006.007.008.009.00

Reductions in Mean Refractive Cylinders

PreopMonth 1Month 3Month 6

Diopters

Patients

Results

For mean topographic cylinder: At the 1-month follow-up, it decreased

from: 5.22 + 1.08 D 4.37 + 2.42 D (P<0.001)

At the 6-month follow-up, it continued to decrease: 5.22 + 1.08D 3.23 + 1.22 D (P<0.001)

There were no statistically significant changes in other topographic measurements

Results

1 2 3 4 5 6 7 8 9 100.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

Reductions in Mean Topographic Cylinders

PreopMonth 1Month 3Month 6

Diopters

Patients

Conclusions

FISAK is a precise, effective, and safe technique in the treatment of high magnitude of corneal astigmatism in post PKP patients

A statistically significant reduction in mean refractive sphere was observed 6 months post FISAK

Significant improvements in both refractive and topographic cylinders were noted early postop, which continued to decrease at the 6-month follow-up

Intrastromal incisions provide a rapid postoperative recovery and an excellent safety profile