Impact of central corneal astigmatism on postoperative visual outcomes in patients undergoing trifocal intraocular lens implantation

To investigate the impact of central corneal astigmatism on postoperative visual outcomes in patients with trifocal intraocular lens (IOL) implantation. This retrospective study included 278 eyes of 278 patients who underwent uneventful cataract surgery with implantation of the trifocal IOL (AT LISA tri 839MP). Patients were divided into two groups according to the total corneal refractive power (TCRP) in 3 mm zone centered on the corneal apex: low astigmatism group, TCRP ≤ 0.75 diopter (D); high astigmatism group, TCRP > 0.75D. Postoperative evaluations were conducted at 3 months after surgery, including visual acuity, defocus curves, contrast sensitivity (CS), and objective and subjective visual quality. The low astigmatism group exhibited significantly better uncorrected near and intermediate visual acuity than the high astigmatism group (both P < 0.05). Significantly higher percentages of eyes in the low astigmatism group achieved uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) of 0.00 logMAR or better compared to the high astigmatism group (UDVA: 67% vs. 54%, CDVA: 76% vs. 64%, both P < 0.05). Defocus curves revealed that the low astigmatism group showed better visual acuity at defocus levels of + 0.5D, 0D, -0.5D, -3.0D, and − 3.5D than the high astigmatism group (all P < 0.05). Moreover, the high astigmatism group showed significantly poorer CS, greater higher-order aberrations, and more symptoms of blurred vision and diplopia. Percentages of spectacle independence and patient satisfaction did not differ between groups. In eyes with central corneal astigmatism above 0.75D, suboptimal postoperative visual outcomes may be obtained after trifocal IOL implantation.