Comparison of bilateral implantation of an extended depth of focus lenses and a blend approach of extended depth of focus lenses and bifocal lenses in cataract patients

Abstract

Background: To compare the visual outcomes, spectacle independent rate and stereopsis in patients who underwent bilateral implantation of extended depth of focus (EDOF) intraocular lens (IOL), or a blend approach of EDOF and bifocal IOL.

Methods: A total of 60 cataract patients, who were scheduled for phacoemulsification and intraocular lens implantation in both eyes in West China Hospital of Sichuan University, were enrolled and divided into Micro monovision group(-0.5D~-1.0D), Non-micro monovision group (< 0.5D) with Symfony IOL, and Mixed group with Symfony and ZMB00 IOLs. Three months postoperatively, we compared the visual acuity, modulation transfer function (MTF), defocus curve, stereopsis, spectacle independence, and photic phenomena among the three groups.

Results: Compared to the Non-micro monovision group (UNVA: 0.07 ± 0.04), Micro monovision group (UNVA: 0.00 ± 0.07, P < 0.001) and Mixed group (UNVA: -0.02 ± 0.06, P < 0.001) showed improvement in binocular uncorrected near visual acuity (UNVA). Additionally, Mixed group exhibited lower MTF10 (MTF10: 0.38 ± 0.24) and point spread function (PSF: 0.192 ± 0.269) results in their non-dominant eye compared to both Micro monovision group (MTF10: 0.56 ± 0.21, P = 0.027; PSF: 0.417 ± 0.282, P = 0.034) and Non-micro monovision group (MTF10: 0.55 ± 0.19, P = 0.038; PSF: 0.408 ± 0.285, P = 0.003). Spectacle independence for near vision were higher in both the Micro monovision (45%) and Mixed (55%) group compared to the Non-micro monovision group (40%). The Mixed group also reported higher incidence of photic phenomena (25%). However, there were no significant differences in stereoscopic function among the three groups.

Conclusion: Both micro monovision and mix-and-match methods can help patients to obtain better visual outcomes at different distances. Mix-and-match method has better near visual acuity, while micro monovision method has better intermediate visual acuity. Non-micro monovision methods will affect patients' near vision outcomes. Binocularly implanted EDOF IOL has better contrast sensitivity.

Clinical trial registration: Registration date:11/07/2023.

Trial registration number: ChiCTR2300073433.

Trial registry: West China Hospital of Sichuan University retrospectively registered.

Keywords: Blend; Cataract; Micro monovision; Presbyopia corrected intraocular lens.

Fig. 1

Three months post-op defocus curves (A: micro monovision group, B: non-micro monovision group, C: mixed group, D: Comparison of bilateral defocus curve)