Woman undergoes LASIK with Zyoptix

Age adjustment is not necessary with this system, surgeon says.

Issue: March 15, 2005

ByMark E. Johnston, MD, FRCSC

Case History: A 27-year-old female physician assistant presented for routine LASIK. Wavefront measurement was done after application of 0.5% tropicamide, and the full wavefront correction was used for laser ablation. Results at 2 months after surgery are reported.

Preoperative:

Manifest refraction: –2.25 20/20
Wavefront phoropter predicted refraction at 3.5 mm: –1.67 –0.25 × 142
System: Bausch & Lomb Zyoptix

Postoperative:

Uncorrected visual acuity: 20/15
Manifest refraction: Plano
Wavefront phoropter predicted refraction at 3.5 mm: +0.54 –0.18 × 6
Higher-order Zernike RMS for 5.5 mm: Reduced from 0.48 µm preop to 0.38 µm postop
Vertical coma: Reduced from –0.27 preop to +0.12 postop
Horizontal coma: Minimal increase from –0.06 to –0.12
Spherical aberration: Reduced from –0.27 to +0.07

Discussion: With other laser systems, we have traditionally made an age adjustment. We have not found this necessary with the Zyoptix. Based on an average preoperative spherical equivalent of –2.74 and average age of 35 years, our average postoperative manifest spherical equivalent is –0.10 (standard deviation 0.36). Regression analysis of our results showed that the average outcome in diopters is –0.03 (0.02 × age). This gives an average outcome of –0.07 for a 20-year-old patient and –0.12 for a 45-year-old patient.

chart
A 3-D view of the preoperative wavefront.

Images: Johnston ME

chart
A 3-D view of the postoperative wavefront.

For Your Information:

Mark E. Johnston, MD, FRCSC, can be reached at Nebraska Laser Eye Associates, 825 North 90th St., Omaha NE 68114; 402-397-2010; fax: 402-397-8439; e-mail: johnston@nebraskaeye.com. Dr. Johnston has no financial interest in Bausch & Lomb.