Comparison of tolerance to induced astigmatism in pseudophakic eyes implanted with dual-technology diffractive IOL and enhanced monofocal IOL.

Abstract

Purpose: To compare the effect of induced astigmatism and defocus on visual performance in patients with a dominant eye implanted with a dual-technology diffractive intraocular lens (IOL) or an enhanced monofocal IOL.

Methods: This non-randomized cohort study included 35 patients in each group. Group 1 underwent phacoemulsification and received the Tecnis Synergy IOL in the dominant eye. Group 2 received the Tecnis Eyhance IOL. All surgeries were performed using a 2.2 mm clear corneal incision. Patients were evaluated 16 weeks postoperatively. Astigmatic tolerance was assessed by measuring monocular distance visual acuity (DVA) using negative cylindrical (CYL) lenses of varying powers and axes on a defocus curve.

Results: There were no significant differences in overall induced astigmatism between groups. However, Group 1 showed significantly better DVA with against-the-rule (ATR) astigmatism (90°) than with-the-rule (WTR, 180°) using 1.50 D CYL (P < 0.05). Additionally, Group 1 outperformed Group 2 at 1.00 D and 1.50 D ATR under -1.00 D defocus (P < 0.05). These findings were both statistically and clinically relevant, indicating that residual ATR astigmatism may be better tolerated by patients with a dual-technology diffractive IOL, resulting in improved performance for near and intermediate tasks.

Conclusion: The Tecnis Synergy IOL demonstrated superior tolerance to ATR astigmatism compared to the Tecnis Eyhance IOL, especially at higher cylindrical powers under -1.00 D defocus. These results highlight the relevance of astigmatic tolerance in IOL selection for spectacle independence, particularly in patients with ATR astigmatism. Findings are specific to these IOLs and should not be generalized to other premium lenses.