Diagnostic intraoperative optical coherence tomography (OCT) for the prediction of postoperative intraocular lens position during femtosecond refractive laser-assisted cataract surgery (ReLACS)

Session Details

Session Title: Femto Cataract II

Session Date/Time: Monday 15/09/2014 | 14:30-16:30

Paper Time: 15:32

Venue: Boulevard B

First Author: : J.Ma CANADA

Co Author(s): :    A. Zhu   C. Law           

Abstract Details

Purpose:

To predict intraocular lens position from the use of algorithm derived OCT data obtained intraoperatively during femtosecond ReLACS procedures to potentially improve post-operative refraction.

Setting:

University Affiliated Private Practice

Methods:

A retrospective review of 52 eyes that had undergone femtosecond ReLACS was performed to improve refractive outcomes. Intraoperative biometric OCT data was obtained from the ReLACS device and this was compared to ocular biometry measured pre-operatively and post-operatively. Correlation coefficients, t-tests and Bland Altman plots were performed between different methods of testing. Algorithm derived OCT data was compared to Scheimpflug imaging measured and manually validated intraocular lens position (iLP) post-operatively at > 1month post-op. Theoretical anterior chamber depth (ACD) estimates of effective lens position (ELP) were calculated based on pre-operative biometry and this was compared both to the iLP and algorithm derived OCT data.

Results:

Average post-operative follow-up was obtained at approximately 2mo (avg. 79d). The average iLP measured by Scheimpflug imaging and manually validated by direct visualization was 5.18mm (SD: 0.29). The average estimate of iLP with aOCT data was 5.02mm (SD 0.36) with a correlation coefficient of r=0.50. In comparison, the average estimate of iLP with a theoretical ACD based on pre-operative axial length, pre-operative ACD, lens thickness, keratometry and refraction was 5.41 (SD:0.49) with a r=0.39. The average pachymetry, pre-operative ACD, and lens thickness as estimated by algorithm derived OCT data had correlation coefficients of r=0.872, r=0.910 and r=0.942 respectively in comparison to values obtained by optical low coherence reflectometry, with p<0.01 for all metrics.

Conclusions:

Algorithm derived intraoperative OCT preformed at the time of ReLACS can provide an accurate estimate of iLP as well as other biometric parameters that is at least as good if not better than theoretically calculated estimates of ELP based on pre-operative biometry. Further refinements in this algorithm can potentially result in more accurate post-operative refractive outcomes.

Financial Interest:

One or more of the authors... receives consulting fees, retainer, or contract payments from a company producing, developing or supplying the product or procedure presented, One or more of the authors... receives consulting fees, retainer, or contract payments from a competing company