Threshold limit of postoperative astigmatism for patient satisfaction after refractive lens exchange and multifocal intraocular lens implantation

Purpose: To determine the degree of tolerance toward different magnitudes of residual refractive astigmatism and corneal astigmatism and the angles of corneal astigmatism after implantation of an asymmetric multifocal intraocular lens (IOL).

Setting: Cathedral Eye Clinic, Belfast, United Kingdom.

Design: Retrospective comparative case series.

Methods: The study enrolled patients having refractive lens exchange and implantation of a Lentis Mplus LS-312 MF30 IOL. Uncorrected (UDVA) and corrected distance visual acuities, uncorrected near and intermediate visual acuities, and quality-of-vision questionnaires were evaluated. Groups were categorized based on the magnitude of refractive astigmatism and corneal residual astigmatism. Refractive astigmatism of less than 0.50 diopter (D) and more than 0.50 D and corneal astigmatism of 0.50 D or less, 0.51 to 0.75 D, 0.76 to 1.00 D, and more than 1.00 D were categorized.

Results: The study comprised 117 patients (234 eyes). There was a significant difference in UDVA (P = .003), refractive sphere (P = .001), and defocus equivalent (P ≤ .001) between the residual refractive astigmatism groups; however, there was no difference in quality of vision (P = .28). The same was found for corneal astigmatism with UDVA (P ≤ .001) and quality of vision (P = .16). The angle of corneal astigmatism in relation to IOL placement did not statistically affect postoperative outcomes.

Conclusions: The IOL appeared to subjectively tolerate residual astigmatism well despite a statistically significant difference in UDVA with higher magnitudes of residual astigmatism. The angle of residual corneal astigmatism in relation to IOL placement did not have a significant effect on postoperative outcomes.

Financial disclosure: None of the authors has a financial or proprietary interest in any material or method mentioned.