Posters

Correction of astigmatism during cataract surgery by incision techniques (as limbal relaxing incision and arcuate keratotomy) versus general applicability of nomograms (particularly Lindstrom’s nomogram)

Poster Details

First Author: M.Královcová CZECH REPUBLIC

Co Author(s):    J. Vacha                    

Abstract Details

Purpose:

The research of the effectiveness of incision techniques (limbal relaxing incision (hereinafter LRI) and arcuate keratotomy (hereinafter AK)) on correction of astigmatism performed during cataract surgery. Our question is if incision techniques could be performed in larger scale than indicated by nomograms, and thus the nomograms, in particular Lindstrom’s nomogram, are generally applicable in today’s cataract surgery.

Setting:

We observed 42 eyes of 41 patients in Regional hospital Pribram from October 2012 to February 2015, who undertook an ordinary cataract surgery (phacoemulsification + posterior chamber intraocular lens implantation) and simultaneously an additional correction of astigmatism by inexpensive and easy available incision techniques performed in accordance with Lindstrom’s nomogram.

Methods:

According to the rate of astigmatism,1 or 2 LRIs were performed; moreover by the astigmatism over 2,0 cyl., 2 AKs were also performed, and thus in 7 mm optical zone and in 60° arc straddling the steep axis. Measuring of astigmatism took place before the surgery and then in three intervals after it. Astigmatism was measured by IOL Master, auto refractometer and we tested the best corrected visual acuity as well. The depth of incision was determined 80% of pachymetry value which was ascertained by anterior segment optical coherence tomography. The assistant for positioning of incision was used for accuracy.

Results:

The research revealed that astigmatism measured in 3 months after the surgery declined to 40% or less in comparison with the pre-operative figures by only 17% of patients. By majority (66%) of patients the decrease of astigmatism amounts to 40-80% of pre-operative figures. Specifically for patients who undertook correction of astigmatism by 2 LRIs and 2 AKs, the residual astigmatism declined to the same scale of 40-80% of pre-operative figures by even 83% of them. To patients with the astigmatism over 2,5 cyl., we implanted toric IOLs.

Conclusions:

The results put a question regarding the general applicability of nomograms (particularly Lindstrom’s) in today’s cataract-refractive surgery. For the optimization of post-operative corneal astigmatism, we suggest performing of incision techniques also by lower rates of pre-operative astigmatism compared to Lindstrom’s nomogram and/or deepening of the incision up to 90% of ascertained pachymetry value. However, all these suggestions will be subject to our further studies.

Financial Disclosure:

NONE