Comparative Study Evaluating Refractive and Visual Outcome of 3 Commercially Available Toric IOLs in Asian Eyes
Purpose
To evaluate the refractive and visual outcomes of consecutive eyes that were randomized to one of three commercially available toric intraocular lenses for correction of pre-existing corneal astigmatism during routine cataract surgery between the 1st of June 2011 and the 31st of December 2012.
Methods
The experimental design was a single institution single surgeon randomized interventional case series. Consecutive patients with topographic corneal astigmatism between 1.5 diopters (D) and 6.5 diopters (D) were randomized for implantation to one of three commercially available toric intraocular lenses after clear cornea phacoemulsification. The lenses included the Alcon Acrysof IQ toric lens, the AMO Tecnis toric lens and the Bausch and Lomb enVista Toric lens. Preoperative IOL calculations were performed by laser interference biometry. Appropriate IOL-torus alignment was determined by intraoperative marking with the patient in upright position. Refraction and uncorrected distance (UDVA) and corrected distance visual acuities were measured 1 day, 1 week, and 1 and 3 months postoperatively and compared between groups.
Results
Overall 28 eyes from 26 patients were included. 19 of these eyes underwent implantation of the Alcon toric lens, while 6 had the AMO lens and 3 had the B&L lens implanted. The mean refractive astigmatism decreased from -3.93D ± 1.80(SD) (range -1.50 to -9.00D) to -0.82 ± 0.82(SD) (range 0 to -3.0D). The predicted residual astigmatism was -0.49D ± 0.82(SD) (range -0.07 to -3.73D). Patients achieved a mean UDVA of 0.33 ± 0.21(SD) (logMAR range 0.1 – 1.0) at 3 months post-op. Between groups, the difference between predicted and actual residual astigmatism at 3 months post-op for Alcon lens, AMO lens and B&L lens were -0.21D ± 0.74(SD), -0.57D ± 0.70(SD) and -0.14D ± 0.51(SD) respectively. There was no statistically significant difference in accuracy between the different lenses used.
Conclusion
All three toric intraocular lenses achieved predictable refractive outcomes and satisfactory visual outcomes. A larger sample size in this ongoing project will aid to identifying smaller differences in accuracy between the lenses.