Assessing the astigmatism-reducing effect of toric intraocular lenses in eyes with low astigmatism: randomized masked bilateral comparison.

PURPOSE: To evaluate the astigmatism-reducing effect of toric intraocular lenses (IOLs) for low amounts of corneal astigmatism.

SETTING

Hanusch Hospital, Vienna, Austria.

DESIGN

Randomized, masked, controlled trial with bilateral comparison.

METHODS

Patients scheduled for bilateral cataract surgery and a corneal astigmatism in both eyes between 0.75 diopters (D) and 1.5 D were included in this study. The first eye was randomized to receive either a toric IOL or a nontoric IOL, and the contralateral eye received the other type of IOL. At the follow-up visits, optical biometry, corneal measurements with tomography and topography, autorefraction, subjective refraction, corrected and uncorrected distance visual acuity (CDVA/UDVA) with ETDRS charts and a questionnaire were performed.

RESULTS

58 eyes were included in the study. Postoperative median UDVA was 0.00 (logMAR) in the toric eyes and 0.10 in the nontoric eyes ( P = .03). The median CDVA was 0.00 in both groups ( P = .60). Median residual astigmatism determined by subjective refraction and autorefraction in the toric eyes was 0.25 D and 0.50 D, respectively ( P = .04), and 0.50 D and 1.00 D in the nontoric eyes, respectively ( P < .001).

CONCLUSIONS

The use of a toric IOL appears to be appropriate from a threshold value of approximately 0.75 D preoperative corneal astigmatism. Further studies in a larger patient population are needed to confirm these results.