J Korean Ophthalmol Soc.  2015 Nov;56(11):1712-1719. 10.3341/jkos.2015.56.11.1712.

The Change in Corneal Astigmatism after Cataract Surgery in Patients with Small Amount of Astigmatism

• Yang HJ
• Park YL
• Kim HS

• KMID: 2214179
• DOI: http://doi.org/10.3341/jkos.2015.56.11.1712

Abstract

PURPOSE
To analyze the change in posterior corneal astigmatism and total corneal astigmatism in patients with anterior corneal astigmatism less than 1.0 diopter (D).
METHODS
In the present study we evaluated 52 eyes with anterior corneal astigmatism less than 1.0 D. Patients were divided into 2 groups according to steep axis: Group 1 included 33 eyes with within-the-rule (WTR) astigmatism and Group 2 included 19 eyes with against-the-rule (ATR) astigmatism. Anterior, posterior and total corneal astigmatism were measured using Scheimpflug imaging (Pentacam(R)).
RESULTS
In Group 1, preoperative anterior astigmatism, posterior astigmatism and total astigmatism were 0.55 +/- 0.44 D, 0.31 +/- 0.14 D and 0.30 +/- 0.72 D, respectively. At postoperative 2 months, anterior astigmatism, posterior astigmatism and total astigmatism were 0.51 +/- 0.67 D, 0.31 +/- 0.15 D and 0.35 +/- 0.81 D, respectively. There was no statistically significant difference between preoperative and postoperative anterior, posterior and total corneal astigmatism in Group 1. In Group 2, preoperative anterior astigmatism, posterior astigmatism and total astigmatism were -0.48 +/- 0.46 D, 0.26 +/- 0.09 D and -0.51 +/- 0.65 D, respectively. At postoperative 2 months, anterior astigmatism, posterior astigmatism and total astigmatism were -0.17 +/- 0.68 D, 0.25 +/- 0.13 D and -0.30 +/- 0.55 D, respectively. There was no statistically significant difference between preoperative and postoperative anterior, posterior and total corneal astigmatism in the 2 groups. There was no statistical correlation between preoperative posterior corneal astigmatism and postoperative 2 months total corneal astigmatism. After vector analysis, surgically induced astigmatism (SIA) of the anterior and total astigmatism in Group 1 were 0.03 D @ 30degrees and 0.07 D @ 74degrees, respectively, and in Group 2 were 0.27 D @ 100degrees and 0.36 D @ 86degrees, respectively.
CONCLUSIONS
In patients with preoperative total corneal astigmatism less than 1.0 D, posterior corneal astigmatism had a small effect on postoperative total corneal astigmatism.

Keyword

Pentacam; Posterior corneal astigmatism; Total corneal astigmatism

MeSH Terms

Astigmatism*
Axis, Cervical Vertebra
Cataract*
Humans

Figure

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  Figure 1. Double-angle plots of surgically induced astigmatism (SIA) of anterior corneal astigmatism (SIA-A) and total corneal as-tigmatism (SIA-T) in (A) WTR group and (B) ATR group. WTR = within-the-rule; ATR = against-the-rule.

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  Figure 2. Correlation analysis between preoperative anterior astigmatism and posterior astigmatism in (A) total group, (B) WTR group and (C) ATR group. WTR = within-the-rule; ATR = against-the-rule.

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  Figure 3. Correlation analysis between preoperative posterior astigmatism and postoperative total astigmatism in (A) WTR group and (B) ATR group. WTR = within-the-rule; ATR = against-the-rule.

Reference

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