Prediction accuracy of intraoperative aberrometry compared to pre-operative biometry formulas for intraocular lens power selection

Session Details

Session Title: Cataract
Session Date/Time: Saturday 16/02/2019 | 08:30-11:00
Paper Time: 08:36
Venue: Hall Trianti

First Author: J.Ma CANADA
Co Author(s): S. El-Defrawy  J. Lloyd  A. Rai           

Abstract Details

Purpose:

Evolution of intraocular lens (IOL) power prediction formulas and development of new technologies have led to improved refractive outcomes in modern cataract surgery. Given recent advances, there is a parallel increase in patient expectations regarding refractive outcomes and achieving spectacle independence is a major determinant of patient satisfaction. Intraoperative aberrometry is a new development which measures the refractive power of an aphakic eye intraoperatively to predict the residual refractive error expected for certain IOL powers. This study aims to compare the accuracy of intraoperative aberrometry with seven formulas based on pre-operative biometry for predicting IOL power.

Setting:

All participants underwent cataract surgery with one of three surgeons at Kensington Vision & Research Centre, affiliated with the University of Toronto.

Methods:

Consecutive, retrospective case series of 49 eyes undergoing cataract extraction with monofocal and trifocal IOL implantation without previous PRK/LASIK. For each eye, an IOL power was selected based on pre-operative biometry measurements from the IOLMaster 500. The spherical equivalent (SE) was predicted pre-operatively with the Barrett Universal II, SRKT, Holladay I, Holladay II, Haigis, HofferQ, and Hill-RBF formulas and intraoperatively with wavefront aberrometry. For each formula, the 1 month post-operative SE was compared with the predicted SE to determine the prediction error. The proportion of eyes with a post-operative SE within 0.5D of the refractive target was also calculated.

Results:

The analysis included 34 eyes. Formulas with the lowest mean prediction error were intraoperative aberrometry (0.27D), Hill-RBF (0.30D), Haigis (0.31D), Barrett Universal II (0.31D), Holladay II (0.36D), Holladay I (0.38D), SRKT (0.38D), and HofferQ (0.42D). Formulas with the highest proportion of eyes within 0.5D of the refractive target were intraoperative aberrometry (85%), Barrett Universal II (85%), Hill-RBF (82%), Holladay II (79%), Haigis (79%), SRKT (74%), Holladay I (71%), and HofferQ (68%). In 56% of eyes, intraoperative aberrometry recommended a different IOL power than the surgeon previously chose. In 29% of eyes, the IOL power implanted differed from the pre-operative choice.

Conclusions:

Based on preliminary results, intraoperative aberrometry has a lower mean prediction error than pre-operative biometry formulas. Intraoperative aberrometry and the Barrett Universal II formula were equally effective at achieving a post-operative spherical equivalent within 0.5D of the refractive target. Data collection is ongoing and we hope to establish statistical significance with further results and larger sample sizes.

Financial Disclosure:

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