Influence of with-the-rule and against-the-rule astigmatism on visual acuity in eyes after monofocal intraocular lens implantation

Poster Details

First Author: T.Hiraoka JAPAN

Co Author(s):    T. Yamamoto   S. Beheregaray   F. Okamoto   T. Oshika     

Abstract Details

Purpose:

To investigate the influence of with-the-rule (WTR) and against-the-rule (ATR) astigmatism on visual acuity in eyes after monofocal intraocular lens (IOL) implantation.

Setting:

University of Tsukuba

Methods:

Forty-five eyes of 39 patients (age; 51-86 years), who underwent phacoemulsification and aspiration with monofocal aspheric IOL implantation for cataract and showed postoperative spherical equivalent refractive error within ± 0.5 diopter (D) and refractive astigmatism ? 0.5 D, were included in this study. These eyes were divided into two groups such as with-the-rule (WTR) and against-the-rule (ATR) astigmatism groups (26 vs. 19 eyes, respectively). Astigmatism was defined as WTR when the steep meridian was 90 ± 30 degrees and ATR when the steep meridian was 180 ± 30 degrees. Eyes with oblique astigmatism were excluded from the study. Age, spherical equivalent refractive error, amount of astigmatism, pupil size, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and ocular wavefront aberration were compared between the two groups. Correlations between UDVA and other parameters were also examined in each group.

Results:

UDVA was 0.14 ± 0.22 logMAR (mean ± SD) in the ATR group and 0.34 ± 0.24 logMAR in the WTR group, showing a significant difference between the groups (p = 0.0065). There were no significant differences in age, spherical equivalent refractive error, amount of astigmatism, pupil size, CDVA, and higher-order aberrations between the groups. UDVA was significantly correlated with the amount of astigmatism (r = -0.500, p = 0.0100) in the ATR group, but not in the WTR group. No other parameters including higher-order aberrations showed no significant correlations with UDVA in both groups.

Conclusions:

After monofocal IOL implantation, UDVA in eyes with ATR astigmatism was worse than that with WTR astigmatism. UDVA was significantly influenced by the amount of astigmatism in eyes with ATR astigmatism. Higher-order aberrations did not affect UDVA and CDVA regardless of the axes of astigmatism. FINANCIAL DISCLOSURE?: No