Axis difference between corneal and internal astigmatism to consider for toric intraocular lenses

Session Details

Session Title: Interactive Free Paper Session: Pseudophakic IOLs/ Toric

Session Date/Time: Monday 15/09/2014 | 16:30-18:30

Paper Time: 16:36

Venue: Capital Hall B

First Author: : J.Song SOUTH KOREA

Co Author(s): :    Y. Eom   H. Kim           

Abstract Details

Purpose:

To evaluate the axis difference between corneal and internal astigmatism in patients with cataract because if the axis of corneal astigmatism is opposite to the axis of internal astigmatism, the amount of refractive astigmatism will increase after cataract surgery due to disappearance of the neutralizing effect of the crystalline lens on corneal astigmatism.

Setting:

Retrospective cross-sectional study.

Methods:

One hundred eighty patients (180 eyes) who underwent cataract surgery by a single surgeon were enrolled. Preoperative refractive, corneal, and internal astigmatism were measured using a wavefront analyzer and retrospectively analyzed. On-axis was defined as an axis difference between the corneal and internal astigmatism of 180°±10°. Opposite-axis was defined as an axis difference between the corneal and internal astigmatism of 90°±10°. The remaining cases were defined as oblique-axis.

Results:

Corneal and internal astigmatic vectors showed a tendency to have the opposite direction. An on-axis difference was seen in 10.0% of patients (18 eyes), oblique-axis in 69.4% of patients (125 eyes), and opposite-axis in 20.6% of patients (37 eyes). Of all eyes, 10.0% had an opposite-axis difference with more than 1.00 D of both corneal and internal astigmatism. The proportion of eyes with an opposite axis difference with both corneal and internal astigmatism of greater than 1.00 D (42.9%) was higher than that of eyes with an opposite axis difference with corneal or internal astigmatism of less than or equal to 1.00 D (13.8%) (P<.001).

Conclusions:

10.0% of all eyes with cataract had an opposite-axis difference with more than 1.00 D of both corneal and internal astigmatism. In these cases, surgical techniques to reduce corneal astigmatism such as a toric IOL should be recommended to increase patient satisfaction.

Financial Interest:

NONE