Comparison of the keratometry measurements, magnitude and axis of astigmatism between a new image-guided system for surgical planning and an optical biometer in patients undergoing cataract surgery

Session Details

Session Title: Cataract Surgery Equipment. Cataract Surgery Outcomes

Session Date/Time: Monday 07/09/2015 | 16:30-18:30

Paper Time: 17:16

Venue: Main Auditorium

First Author: : S.Lane FRANCE

Co Author(s): :    P. Crozafon   S. Slade   R. Cionni   K. Solomon           

Abstract Details

Purpose:

To determine lack of agreement between Verion and LenStar with respect to keratometry measurements, magnitude of astigmatism and axis of astigmatism.

Setting:

Multi-center study at surgical sites in the United States and Europe. Slade & Baker Vision Center The Eye Institute of Utah Carolina Eye Care

Methods:

This is an open-label, prospective, observational, non-randomized, multi-center study involving 393 eyes of 277 astigmatic cataract patients. Pre-operative steep K, flat k, mean k, magnitude of astigmatism and axis of astigmatism for patients with cylinder greater than and equal to 0.75D were measured with the LenStar and with the Verion. Corneal topography axis measurement was also taken. The axis reading taken from the Verion and LenStar was compared with the measurements from the corneal topographer.

Results:

The mean absolute difference between the Verion and LenStar magnitude of astigmatism was 0.20 ± 0.21 [95% confidence interval (CI) = 0.182, 0.224]. This is within a within the preset clinical margin of ±0.25D. The mean absolute difference between Verion and LenStar axis of astigmatism was 6.1 ± 10.7 [95% CI = 5.0, 7.2] which is within the preset clinical margin of 10 degrees. The mean absolute difference between the Verion and LenStar mean k was 0.33± 0.31 [95% CI = 0.299, 0.360]. The corneal curvature is not within the preset clinical margin of ±0.25D.

Conclusions:

There is agreement between Verion and LenStar in magnitude and axis of astigmatism which allows users to readily use these data from Verion for astigmatism management. There is lack of agreement on the keratometry readings which suggests that re-optimization of the A-constant is recommended when using the K value from the Verion to achieve target refraction. .

Financial Interest:

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