Predictability of different strategies to consider total corneal astigmatism in cataract surgery with a toric intraocular lens

Session Details

Session Title: Toric IOL Calculations & Alignment

Session Date/Time: Sunday 23/09/2018 | 08:00-10:00

Paper Time: 08:12

Venue: Room A5

First Author: : T.Ferreira PORTUGAL

Co Author(s): :    F. Ribeiro   P. Ribeiro   J. O'Neill              

Abstract Details

Purpose:

To assess the prediction error in cylindrical power calculation of a toric intraocular lens (IOL) (Precizon Toric, Ophtec BV) in cataract surgery using four different calculation strategies.

Setting:

Hospital da Luz, Lisbon, Portugal.

Methods:

Spherical IOL power was calculated using the Barrett Universal II formula. The cylindrical power was calculated in the online Ophtec calculator (group 1); Total Corneal Refractive Power (TCRP) of a Scheimpflug camera (Pentacam HR, OCULUS Optikgeräte GmbH) (group 2); Total Corneal Astigmatism of a color-LED topographer (Cassini, i-Optics) (group 3) or Barrett toric calculator (group 4). In each of the groups 2 to 4, 20 eyes were included in a prospective randomized fashion. Group 1 was a historical control group of 51 eyes. The mean absolute prediction error (MAE) in cylindrical power calculation was analyzed using Alpins method.

Results:

The MAE in predicted toric IOL cylindrical power was reduced from 0.56 D (0.26 – 1.09) in group 1 to 0.48 D (0.20 – 1.10) in group 2, 0.18 D (0.05 – 0.34) in group 3 and 0.14 D (0.04 – 0.21) in group 4. There were no statistically significant differences between groups 1 and 2 (p = 0.109) and between groups 3 and 4 (p = 0.099). The percentage of eyes within 0.50 D of MAE in predicted cylindrical power was 54% in group 1, 57% in group 2, 71% in group 3 and 74% in group 4.

Conclusions:

Using color-LED topography TCA data or the Barrett toric calculator significantly reduces the absolute error in cylindrical power calculation when implanting a toric IOL, with both methods showing similar results. Using one of these calculation methods improves clinical results with toric IOLs.

Financial Disclosure:

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