Comparing Intraoperative Wavefront Aberrometry With Different IOL Power Calculation Methods in Patients With Prior Myopic Refractive Surgery

Monday, April 28, 2014: 3:11 PM
Room 150 (Boston Convention and Exhibition Center)
Anthony Farah, MD, Wills Eye Hospital, Philadelphia, PA, USA
Mark Blecher, MD, Philadelphia Eye Associates, Philadelphia, PA, USA
Jeffrey F. McMahon, BS, Jefferson Medical College, Philadelphia, PA, USA
Robert S. Bailey Jr., MD, Wills Eye Hospital, Philadelphia, PA, USA
Sagun J. Pendse, MD, Wills Eye Hospital, Langhorne, PA, USA

Narrative Responses:

Purpose
To evaluate three different surgeons method of calculating pre-operative IOL power in post-refractive patients and to compare each method to intraoperative wavefront aberrometry.

Methods
A retrospective study of 24 eyes was conducted analyzing the refractive outcomes in patients having undergone cataract surgery. All patients had a history of prior myopic refractive surgery. 

Surgeon 1 selected IOL power predicted by the ASCRS website with no historical data. Surgeon 2 selected IOL power predicted by the ASCRS website with historical data. Surgeon 3 selected IOL power based on average keratometry readings from Orbscan topography which were plugged into the Holladay 2 formula.

Post-operative spherical equivalent was then used to determine the accuracy of intraoperative wavefront aberrometry versus the pre-operative method chosen by each surgeon.

Results
*Preliminary

Average difference between pre-operative IOL power and ORA suggested IOL power 

Surgeon 1: 0.50D 

Surgeon 2: 0.67D

Surgeon 3: 1.14D

ORA Accuracy: Difference between predicted Spherical Equivalent of Implanted IOL and Post-Operative Spherical Equivalent 

Surgeon 1 (n=5)                              

Within 0.25D: 40%

Within 0.50D: 60%

Within 0.75D: 80%

Within 1.0D: 80%

Surgeon 2 (n=12)

Within 0.25D: 33%

Within 0.50D: 67%

Within 0.75D: 83%

Within 1.0D: 100%

Surgeon 3 (n=7)

Within 0.25D: 0%

Within 0.50D: 0%

Within 0.75D: 14%

Within 1.0D: 43%

*data for pre-operative methods pending

Conclusion
*Final conclusion pending

Preliminary conclusions: Surgeon 1 and 2's method for selecting pre-operative IOL power (ASCRS website) more closely correlates with the IOL power suggested by the ORA than Surgeon 3's pre-operative method. Surgeon 1 and 2's method may be more accurate in predicting post-operative spherical equivalent.