Vector analysis of astigmatic changes after cataract surgery with implantation of a new toric multifocal intraocular lens.

Objective: To analyze the astigmatic changes after cataract surgery with the implantation of a new toric multifocal intraocular lens (IOL) using the Alpins vector method.

Methods: Vissum-Instituto de Oftalmológico de Alicante, Alicante, Spain. Methods: Prospective case series. Methods: After cataract surgery with implantation of an AT Lisa 909M toric multifocal IOL, the visual, refractive, corneal topographic, internal astigmatism, defocus curves, and contrast sensitivity outcomes were evaluated over 6 months. Refractive astigmatic changes (target astigmatism [TIA]; surgically induced astigmatism [SIA]; difference vector; magnitude of error; flattening effect; torque) were analyzed using the Alpins vectorial method.

Results: The study enrolled 23 eyes (12 patients). Postoperatively, there was a significant reduction in refractive cylinder (P < .01) with an associated visual improvement for near (P = .03) and distance (P=.01). The magnitude of SIA vector was significantly larger than the TIA 3 months postoperatively (P = .03). The mean magnitude of the difference vector was 0.67 diopter (D) ± 0.51 (SD) at 6 months. The mean magnitude of error remained positive and close to zero over the entire follow-up (P ≥ .19). The mean magnitude of torque vector was 0.49 ± 0.54 D at 6 months. Significant positive correlation was found between the magnitude of torque and the difference vector (r ≥ 0.70, P<.01).

Conclusions: The new toric IOL restored distance and near visual function with excellent predictability in eyes with moderate to high corneal astigmatism having cataract surgery.