Progressive changes in corneal aberrations in a randomized, controlled study comparing limbal relaxing incisions and toric intraocular lens implantation for correction of astigmatism between 0.75 and 2.5 diopters during standard cataract surgery

Session Details

Session Title: Cataract II
Session Date/Time: Saturday 27/02/2016 | 08:30-11:00
Paper Time: 10:42
Venue: Trianti Room
First Author: : K.Bedi UK
Co Author(s): :    C. Offer   D. Horney   L. Bromilow   F. Winterflood   C. Henein   M. Nanavaty

Abstract Details

Purpose:

To assess the progressive changes in anterior and posterior corneal aberrations after limbal relaxing incisions (LRIs) and toric intraocular lens implantation (tIOL), for the correction of astigmatism between 0.75 diopters and 2.5 diopters during cataract surgery (UKCRN ID: 16848).

Setting:

Data was collected from 33 to 38 patients, depending on the month of visit, at the Sussex Eye Hospital (Brighton & Sussex University Hospitals NHS Trust, United Kingdom).

Methods:

In this prospective, randomized controlled study patients received either LRIs or tIOL implantation. During the preoperative, 1 and 6-month visits, patients underwent assessments with Scheimpflug corneal tomography (Pentacam®, Oculus, Germany). At least 3 measurements were taken of the eye by a single researcher and the best scan was saved for the analysis. The data on anterior and posterior Zernikes polymomials upto 5th order was exported to the Microsoft Excel Spreadsheet (Microsoft Office 2011, USA). Aberrations were compared between each visit using ANOVA test and aberrations between LRI and tIOL groups were compared at each visit using an unpaired t-test.

Results:

Over the three visits, the anterior corneal oblique (ACO) trefoil changed for both (LRI:0.022±0.123μm, -0.162±0.381μm, -0.154±0.317μm; p=0.01, tIOL:0.034±0.171μm, -0.200±0.236μm, -0.114±0.205μm;p<0.01). The ACO quadrufoil (0.020±0.096μm, -0.123±0.266μm, -0.066±0.207μm;p=0.01) and oblique secondary trefoil (0.014±0.033μm, -0.018±0.039μm, -0.011±0.038μm;p=0.001) changed in the LRI group. In the tIOL group, the ACO astigmatism changed (0.084±0.737μm, 0.606±0.752μm, 0.434±0.743μm;p=0.023). Spherical (p=0.043) and vertical quadrufoil (p=0.04) anterior corneal aberrations was greater with the LRI group at 6-months whereas, oblique astigmatism was more with tIOL group (p=0.06) at 1-month. The posterior cornea showed less horizontal tilt in the LRI groups at 1 and 6-months (p=0.019) and horizontal coma less at 1-month (p=0.016).

Conclusions:

LRIs reduced anterior oblique astigmatism transiently up to 1-month, this is followed by changes in anterior corneal oblique quadrufoil and oblique secondary trefoil over 6-months. Posterior corneal aberrations remained consistently stable in each group with the LRI induced showing less horizontal tilt compared to tIOL group.

Financial Disclosure:

NONE