Comparison of visual outcomes with implantation of trifocal versus bifocal intraocular lens after phacoemulsification: a Meta-analysis

AIM: To compare a trifocal intraocular lens (IOL) and a bifocal IOL implantation in improving visual function after cataract surgery. METHODS: Eligible literatures were systematically searched through EMBASE and PubMed databases. The inclusion criteria were prospective comparative clinical trials on cataract surgery comparing trifocal IOL with bifocal IOL implantation that assessed visual acuity, contrast sensitivity and subjective vision quality. The effects were computed as standardized mean differences and pooled using fixed-effect or random-effect models. RESULTS: Four prospective randomized controlled trials (RCTs) and five cohorts provided data were included by a systematic review, comprising 265 eyes implanted with trifocal IOLs and 264 eyes implanted with bifocal IOLs. Monocular distance visual acuity (VA) showed a statistically significant but small difference that favored trifocal IOLs (MD=-0.06; 95% CI, -0.10 to -0.02; Z=2.90, P=0.004 for uncorrected distance VA, and MD=-0.02; 95% CI, -0.03 to -0.00; Z=2.02, P=0.04 for corrected distance VA), but the data did not suggest that the effect of trifocal IOL implantation would clinically outperform bifocal IOL implantation. There was no significant difference in monocular near VA (MD=-0.01; 95% CI, -0.07 to 0.04; Z=0.42, P=0.68 for distance-corrected near VA, and MD=-0.01; 95% CI, -0.06 to 0.03; Z=0.55, P=0.58 for corrected near VA) or refraction between two groups. Contrast sensitivity and subjective visual quality had no conclusive results. CONCLUSION: All results indicate that trifocal IOL and bifocal IOL had similar levels of monocular distance and near VA.