Posters

Correcting small astigmatism during cataract surgery and toric IOL

Poster Details

First Author: M.Molnarova SLOVAKIA

Co Author(s):    M. Duranova   M. Zelnikova   L. Ducova              

Abstract Details

Purpose:

The purpose of refractive cataract surgery is to achieve the patient’s independence from glasses. About 50% of cataract patients have astigmatism approx. 1.0D. During cataract surgery we often have to correct small astigmatism (between 0.75D and 1.5D). Possible solutions are toric intraocular lense (IOL) implantation, limbal relaxing incisions (LRIs) or a combination of both. We conducted a prospective study during which we followed correction and stabilization of primary small astigmatism (up to 1.5D) through toric IOL implantation and analyzed the causes of persistent residual astigmatism after surgery.

Setting:

Ophthalmology center VIKOM, s.r.o., 1. zilinske ocne centrum, Vysokoskolakov 31, 010 08 Zilina, Slovakia

Methods:

We evaluated 38 eyes with cataract and primary astigmatism between 0.75D and 1.5D. Average age was 59.9 years, average follow-up time was 6.1 months. In all cases we provided phacoemulsification cataract surgery with implantation of toric IOL AcrySof IQ T2 and T3. We calculated lense power using Lenstar and cylinder power and axis using an electronic calculator. Before surgery we marked the cylinder axis on limbus using an axial scale on a slit lamp. We examined UCVA and BCVA using a Snellen chart. We measured the power and the axis of postoperative astigmatism using an automatic refractometer and Pentacam analysis.

Results:

We achieved UCVA 1.0 — 0.8 in 79% of eyes and UCVA less than 0.8 in 21% of eyes. UCVA improved from average 0.3 before surgery to average 0.86. Astigmatism was reduced from average 1.4D to average 0.23D. We achieved desired reduction of astigmatism in 34(89.5%) eyes, we found unwanted residual astigmatism in 4(10.5%) eyes. Causes of residual astigmatism were: postoperative axis rotation more than 5 degrees in 2(5.25%) eyes and undercorrection of astigmatism due to non-inclusion of posterior corneal surface curving in the calculator in 2(5.25%) eyes. UCVA less than 0.8 were due to: DME, VMTsy, amblyopia, residual astigmatism.

Conclusions:

The results of our prospective study show that implantation of toric IOL during cataract surgery is a pertinent method for correcting primary small astigmatism yielding highly predictable results. 36(94.75%) of patients are very satisfied with the result. In 2(5.25%) patients we plan follow-up laser correction, last 2(5.25%) eyes we will monitor. Preciseness of results depends on (i) the correctness of the calculation of the power and the axis of the toric IOL, which includes posterior corneal surface curving, and (ii) the preciseness of both centration of the IOL and positioning of the astigmatism axis during surgery.

Financial Disclosure:

NONE