Accuracy of ocular biometry and intraocular lens power calculation using optical low coherence reflectometry

Session Details

Session Title: Cat Surgery Equipment/inst/OVD

Session Date/Time: Tuesday 16/09/2014 | 16:30-18:00

Paper Time: 17:37

Venue: Boulevard B

First Author: : K.Yoon SOUTH KOREA

Co Author(s): :    T. Lee              

Abstract Details

Purpose:

To compare ocular biometry measured by optical low coherence reflectometry (Lenstar®) with that measured by current clinical instruments, evaluate the accuracy of refractive outcomes after cataract surgery and investigate the factors influencing intraocular lens (IOL) power calculation using Lenstar® with and without formula optimization.

Setting:

Department of Ophthalmology, Chonnam National University Hospital, Gwangju, Korea

Methods:

A total of 100 eyes in 86 patients who received cataract surgery were included in this study. Corneal curvature was measured with manual keratometer, automated keratometer and Lenstar®, and axial length was measured with A-scan and Lenstar®. Mean absolute error (MAE) that subtract predictive refraction from postoperative refraction was compared between automated and manual keratometers with A-scan and Lenstar® with and without formula optimization. The factors affecting the accuracy of IOL power calculation by Lenstar® with and without formula optimization were analyzed.

Results:

The corneal power did not differ among instruments, whereas the axial length measurements were significantly longer in Lenstar® than in A-scan (23.37±1.13 vs. 23.20±1.13 mm; p<0.01). No significant differences were observed in MAE between the instruments. The percentage of MAE within 0.5D was higher in Lenstar® with optimization (62.7%) than without optimization (46.2%) (p=0.02). Without formula optimization, the MAE was larger in long or short axial lengths compared with normal axial lengths (p=0.03), while it was larger in low corneal powers when the formula was optimized (p=0.03).

Conclusions:

Optimizing IOL constants for Lenstar® biometry substantially improve refractive outcomes. The axial length may influence the accuracy of refractive outcomes using Lenstar® without formula optimization, and the corneal curvature affect the refractive accuracy using Lenstar® with formula optimization.

Financial Interest:

NONE