In the long-term, does an on-axis incision cause significantly lower surgically induced astigmatism than an off-axis incision?

Session Details

Session Title: Cataract Surgery Outcomes / Femto

Session Date/Time: Monday 15/09/2014 | 08:00-10:30

Paper Time: 09:39

Venue: Auditorium

First Author: : S.Perera UK

Co Author(s): :    H. Ali              

Abstract Details

Purpose:

Cataract incisions affect the corneal curvature and placing the incision on the steeper axis (on axis) has shown to reduce surgically induced astigmatism (SIA). Most of these studies have short term follow up. Corneal curvature has been shown to change with time. This study aims to ascertain if in the long term, an on axis incisions cause less SIA than an off axis incision.

Setting:

Hospital Practice

Methods:

30 consecutive patients who had cataract surgery by the same surgeon, and had automated corneal keratometry done by the IOL Master device both pre and post operatively 1-7 years (mean 4yr.) following the cataract procedure was included in the study. The same surgical technique was used for all eyes with a 2.75mm. primary clear corneal incision placed centred on the horizontal axis and enlarged to 3.00mm for lens insertion. Eyes with the steeper axis between 75-105 degrees were considered to be off axis while those between 0-15 and 165-180 degrees were considered as on axis. SIA was calculated using the vector analysis method from the pre operative and post-operative K readings.

Results:

The mean SIA in the on axis group was 0.567D (SD0.32) with a range of (0.18-1.03D) while that of the off axis group was 0.635D (SD0.34). range (0.11-0.95D) The difference of 0.068D in the SIA seen between the two groups was not statistically significant. (p>0.05) The range of SIA was also similar in the two groups.

Conclusions:

This study suggest that in the long term no statistically significant difference is seen in SIA between on axis and off axis incisions.

Financial Interest:

NONE