Analysis of Miscorrection after Implantation of the Toric Intraocular Lens

ABSTRACT

PURPOSE: To evaluate the efficacy and stability of AcrySof Toric intraocular lens (IOL) implants and to analyze the miscorrection that resulted after implantation. METHODS: This retrospective study included 422 eyes of 348 patients who underwent cataract surgery with implantation of the AcrySof toric IOL between December 2011 and June 2013. We evaluated uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), keratometry and refraction preoperatively and 3 months postoperatively. The axis of implanted AcrySof Toric IOL was measured using the KR-1W aberrometer before mydriasis. At 3 months postoperatively, patients with a residual cylindrical power of 0.50 diopters (D) or more, and having an IOL rotation of 10 degrees (degrees) or more were considered having miscorrection. RESULTS: UCVA (log MAR) improved from 0.58 +/- 0.35 to 0.18 +/- 0.26. Preoperative corneal astigmatism was 1.46 +/- 0.72 D and postoperative refractive cylindrical power was 0.45 +/- 0.30 D. The postoperative miscorrection was 50.5% in the T3 group, 35.7% in the T4 group, and 27.2% in the T5 group. The incidence of overcorrection was significantly higher in the T3 group than in the T4 and T5 group. In eyes with with-the-rule (WTR) astigmatism, overcorrection was found in 36.4% (32/88 eyes), while in eyes with against-the-rule (ATR) astigmatism, undercorrection was found in 37.6% of cases (44/117 eyes). There were five cases of IOL rotation at 3 months postoperatively. CONCLUSIONS: AcrySof Toric IOL was effective in correcting corneal astigmatism and had good rotational stability. However, the incidence of miscorrection, especially for overcorrection, was higher with lower power toric IOL. Patients with WTR astigmatism tend to have overcorrection, while those with ATR show a tendency toward undercorrection, suggesting that these changes considered at the time of cataract surgery.