Effect Of Toric Intraocular Lenses In Eyes With Low Astigmatism

This study investigates the effectiveness of toric intraocular lenses (IOLs) in patients with low corneal astigmatism. It compares the astigmatism-reducing effect of a toric IOL with a non-toric IOL in the same patient with low to moderate corneal astigmatism (0.75 D and 1.5D).

Vienna Institute for Research in Ocular Surgery (VIROS), a Karl-Landsteiner-Institute, Hanusch Hospital, Vienna.

Patients scheduled for bilateral cataract surgery with bilateral corneal astigmatism between 0.75 and 1.5 diopters were included in the study. The first eye to be operated was randomly assigned to receive a toric or a non-toric IOL, and the other eye received the opposite IOL type. Study examinations were performed preoperatively and 6 months after surgery. The examinations included optical biometry, corneal tomography and topography, subjective refraction and autorefraction, best-corrected/uncorrected visual acuity and a questionnaire.

A total of 58 eyes of 29 patients were included in the study. The postoperative median uncorrected distance visual acuity in the toric eyes was 1.0 (Snellen) and in the non-toric eyes was 0.8 (p=0.030). The median best-corrected distance visual acuity was 1.0 in both groups (p=0.598). Median subjective- and auto-refractive corneal astigmatism in the toric eyes were 0.25 D and 0.5 D, respectively, and in the non-toric eyes were 0.5 D and 1.0 D, respectively (p=0.035 and p<0.001).

Toric IOL in eyes with low to moderate amounts of corneal astigmatism showed a significantly better postoperative uncorrected visual acuity as well as subjective and autorefractive postoperative astigmatism.