Comparison of Early Experience With Intraoperative Wavefront Aberrometry IOL Power Calculations in Laser-Assisted Versus Conventional Cataract Surgery

Friday, April 25, 2014
KIOSKS (Boston Convention and Exhibition Center)
Robert J. Weinstock, MD, Eye Institute of West Florida, Largo, FL, USA
Douglas W. Wald Larchmont, NY, USA

Narrative Responses:

Purpose
To compare the preoperative IOL calculations with intraoperative IOL power measurements made by ORA on eyes pretreated with a femtosecond laser and those that were not.

Methods
This was a retrospective study of aphakic intraoperative wavefront IOL power calculations in eyes that underwent conventional cataract surgery (n=45) and laser assisted cataract surgery with either a B+L Victus or LenSx femtosecond laser (n=53).  Each eye had a postoperative target of plano and received a B+L MI60L lens.    Preoperative IOL calculations were compared to ORA measurements.

Results
The mean difference between preoperative and intraoperative IOL calculations in the femtosecond group was -0.37D ±0.53D (p=0.013).  For the conventional surgery group there was a mean difference of -0.1D ±0.67D (p= ­0.32).  Postoperative manifest refraction showed the mean spherical equivalence of the femto group to be -0.251 D ± 0.39D and the non-femto group to be -0.248 D ± 0.41D (p=0.48).  Using the implanted power, the ORA suggested power, and the POMR, the mean postoperative spherical equivalences were -0.66D +/- 0.62D in the femto group and  -0.47D +/- 0.60D for the non-femto group (p=0.058).

Conclusion
Preoperative and intraoperative IOL calculation may differ significantly when the eyes are pretreated with a femtosecond laser.  Relying heavily on intraoperative measurements for lens selection may lead to a higher rate of postoperative myopia in femtosecond laser assisted cataract surgery if variables are not controlled.