Toric IOL improves distance visual acuity, reduces refractive cylinder at 1 month postop

J Cataract Refract Surg. 2011;37(6):1038-1049.

Implantation of a toric IOL improved distance vision despite a slight undercorrection of refractive cylinder related to misalignment of astigmatic correction, a study found.

"Astigmatism is a vectorial variable and thus has an associated magnitude and axis. The vectorial character of astigmatism should be considered for precise, complete analysis of astigmatic changes after cataract surgery with toric IOL implantation," the study authors said.

The prospective study included 27 eyes of 21 patients with visually significant cataract and refractive astigmatism of 1.75 D or more. Mean patient age was 70.05 years.

Fourteen right eyes and 13 left eyes were implanted with AcrySof toric IOLs (Alcon). The Alpins vectorial method was used to assess targeted-induced astigmatism and surgically induced astigmatism. Difference vector, magnitude of error, flattening effect and torque were also evaluated.

Patients were examined preoperatively and at 1 day and 1, 3 and 6 months postoperatively.

Study results showed statistically significant improvements in uncorrected distance visual acuity and corrected distance visual acuity and a significant reduction in refractive cylinder at 1 month (all P < .01).

Mean magnitude of the targeted-induced astigmatism was 2.80 D, and mean magnitude of the surgically induced astigmatism was slightly lower at all follow-up points. Normally, surgically induced astigmatism and targeted-induced astigmatism are equal after toric IOL insertion.