Transcript Femtosecond Laser-Assisted Astigmatic Keratotomy (FSAK)

Femtosecond Laser-Assisted Astigmatic
Keratotomy for Naturally Occurring
Astigmatism
Ashkan M. Abbey, BA, Takeshi Ide, MD, PhD, George D.
Kymionis, MD, PhD, Sonia H. Yoo, MD
Sonia H. Yoo, MD has received honoraria from AMO, Carl Zeiss
Meditec, and Alcon.
Purpose
To evaluate the results of femtosecond laserassisted astigmatic keratotomy (FSAK) for
naturally occurring high astigmatism.
Methods


Two arcuate incisions on the steepest meridians of the cornea were
performed using an IntraLase® femtosecond laser in a consecutive series of 9
patients (13 eyes) with naturally occurring high astigmatism.
Methods
• The femtosecond laser settings were determined
using a modified Lindstrom nomogram.
• Age: 32 to 86 years (54.46 ± 17.50 years)
• Follow-up: 5 to 13 months (Mean 9.8 months)
• A retrospective review evaluated femtosecond
laser settings, uncorrected visual acuity (UCVA),
best spectacle corrected visual acuity (BSCVA),
manifest refraction, and corneal topography.
FSAK Nomogram
UCVA
• Improved in 12 out of 13 eyes (92.3%)
• Pre-FSAK UCVA: 20/25 or worse in all eyes
(range from count fingers to 20/25)
• Latest Follow-up Post-FSAK: All 13 eyes 20/60
or better (range from 20/60 to 20/20)
BSCVA
• Unchanged or improved in 10 eyes (76.9%)
• Pre-FSAK BSCVA: 20/40 or better in all eyes
(range from 20/40 to 20/20)
• Latest Follow-up Post-FSAK: All 13 eyes 20/30
or better (range from 20/30 to 20/20)
UCVA and BSCVA
Astigmatism Change
∆
P
• Manifest cylinder decreased by more than 3 D in
10 out of 13 eyes (76.9%)
• Induced axis change was less than 30 degrees in 9
eyes (69.2%)
• Corneal cylinder decreased by more than 3.00 D
in 9 eyes (69.2%)
Doubled-Angle Plots
Preoperative
Postoperative
Regression Analysis: Preoperative Cylinder in
Keratoplasty Mode Eyes
12.00
y = 1.025x + 2.6846
R² = 0.9497
Change in Corneal Cylinder (D)
10.00
8.00
6.00
4.00
R=0.975, P=0.001
2.00
0.00
0
1
2
3
4
5
Preoperative Cylinder (D)
6
7
8
Conclusions
• FSAK in patients with naturally occurring high
astigmatism appears to be a safe and effective
technique for the reduction of astigmatism.
• The femtosecond laser is able to perform
uniform corneal incisions with precision and a
high degree of predictability.