Converting intraocular lens power from bag to sulcus

Session Details

Session Title: Cataract Surgery Outcomes. IOL Power Calculations

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

Paper Time: 17:10

Venue: Room 1

First Author: : N.Reus THE NETHERLANDS

Co Author(s): :                        

Abstract Details

Purpose:

To describe and analyze a general formula for calculating the power of an intraocular lens (IOL) to be implanted in the ciliary sulcus with a (complicated) cataract operation based on the power of the IOL planned for implantation in the capsular bag.

Setting:

Amphia Hospital, Department of Ophthalmology, Breda, the Netherlands

Methods:

The effective lens positions of a single-piece IOL (ZCB00) in the capsular bag and a multi-piece IOL (ZA9003) in the ciliary sulcus (0.5 mm anterior to the capsular bag) were calculated based on their optimized A constants. With Gaussian thin lens optics, a formula was constructed to convert the power of a given single-piece IOL in the bag to the power of a multi-piece IOL in the sulcus. We then evaluated the refractive outcome of 11 cataract operations complicated by a posterior capsule rupture with implantation of a multi-piece IOL in the ciliary sulcus without optic capture.

Results:

The average power of the multi-piece IOL implanted in the sulcus was 21.7 ± 1.9 D (19.0 to 26.0). The average prediction error was slightly myopic: 0.7 D (0.16 to 1.33). The average ± SD power of a single-piece IOL to be implanted in the bag for the given post-op refraction was 23.1 ± 1.8 D. The difference between implantation in the sulcus versus in the bag was -1.4 D (-0.8 to -2.0). The difference in calculated change in IOL power when converting from bag to sulcus based on the general formula and the measured change in IOL power based on the 11 patients was not statistically significantly different (t test, P = 0.39).

Conclusions:

A general formula was presented to convert the power of any type of single-piece IOL in the capsular bag to any type of multi-piece IOL in the ciliary sulcus based on their effective lens positions. These values correspond well to those found in eyes with a posterior capsule tear with implantation of a multi-piece IOL in the sulcus.

Financial Interest:

NONE