Is Cataract Extraction A Factor Influencing Posterior Corneal Astigmatism In Patients With Preoperative Total Corneal Astigmatism Above 1,5 D?

The objective is to determine the impact of cataract surgery on the  astigmatism power of the posterior surface of the cornea (PCA) in patients with preoperative total corneal astigmatism above 1,5D and check how the type of astigmatism affects the power of PCA.

The study included 104 eyes of 75 patients undergoing cataract surgery with simultaneous implantation of a toric lens at the Ophthalmology Clinic of the 4th Military Hospital of Wrocław in 2020-2023.

 The basic condition for inclusion in the study was the presence of regular corneal astigmatism >1.5D.  All patients underwent optical biometrics using the IOLMaster700 device and corneal topography using the Pentacam device before and 3 months after the procedure. All patients underwent an uncomplicated cataract extraction by the same surgeon, with a 2.2mm width incision on 100°axis and two 1.2mm side ports.Calculations were made using the R programming language (version 4.3, Vienna, Austria). The level of significance was p<0.05.

The average preoperative power of the PCA was: for WTR astigmatism −0.68 ± 0.20 D (range from −0.3 to −1.20 D), ATR −0.16 ± 0.09 D (range from −0.00 to −0.30 D), oblique −0.54 ± 0.12 D (range from −0.3 to −0.7 D).The average postoperative power of the PCA was: for WTR astigmatism −0.66 ± 0.20 D (range from −0.3 to −1.2 D), ATR −0.18 ± 0.12 D (range from −0.0 to −0.4 D), oblique −0.52 ± 0.12 D (range from −0.2 to −0.7 D). WTR astigmatism was present in 66.3% of patients, oblique in 25.0% and ATR in 8.7%.  

1.The obtained correlations do not allow cataract removal with a 2.2 mm incision and two 1.2 mm side incisions to be considered a factor influencing the strength of the posterior corneal astigmatism in patients with preoperative total corneal astigmatism above 1,5D.

2.The posterior corneal astigmatism assumes the highest values ​​in patients with with-the-rule-astigmatism, intermediate in oblique, and the lowest in the against-the-rule (p<0.05)