AIM: To evaluate the retinal image of two types of aspheric diffractive multifocal intraocular lens(IOL).

METHODS: Retrospective cohort study. Totally 155 cases of simple cataract who received phacoemulsification combined with IOLs implantation from October 2017 to October 2019. They were divided into three groups according to the types of IOL: Aspheric Bifocal Diffractive Group: 54 patients(54 eyes); Aspheric Trifocal Diffractive Group: 54 patients(54 eyes); Aspheric Monofocal Group: 47 patients(47 eyes). All patients were evaluated postoperatively at 6mo. Double-pass visual quality analysis system was used to evaluate OSI, MTF cutoff, Strehl Ratio, OV 100%, OV 20% and OV 9% respectively. Uncorrected distance visual acuity(5m), uncorrected intermediate visual acuity(80cm), uncorrected near visual acuity(40cm), corrected distance visual acuity, distance-corrected intermediate visual acuity, distance-corrected near visual acuity were measured and compared among three groups. Visual function-14 was also assessed.

RESULTS:Both of bifocal and trifocal groups had similar MTF cutoff(P=0.445), OV 100%, OV 20% and OV 9%(OV 100%: P=0.974; OV20%: P=0.713; OV 9%: P=0.947). Monofocal group had better MTF cutoff(P=0.007), OV 100%(P=0.001), OV 20%(P=0.002)and OV 9%(P=0.011)than bifocal. Besides, monofocal group had better MTF cutoff(P=0.043), OV 100%(P=0.012), OV 20%(P=0.043)and OV 9%(P=0.029)than trifocal group. There was no difference among all groups in uncorrected distance visual acuity and corrected distance visual acuity(P=0.054, 0.180). There was difference in distance-corrected intermediate(H=91.292, P<0.01)and distance-corrected near visual acuity(H=91.292, P<0.01). Uncorrected intermediate visual acuity was better in trifocal group than bifocal(P<0.01)and monofocal group(P<0.01). Distance-corrected intermediate visual acuity was better in trifocal group than bifocal(P<0.01)and monofocal group(P<0.01). Both of bifocal and trifocal groups have similar uncorrected near visual acuity(P=0.428)and distance-corrected near visual acuity(P=0.519), which was better than monofocal group(P<0.01). In terms of VF-14, score in bifocal and trifocal groups are significantly higher than the monofocal group(P<0.01). There was no difference in bifocal and trifocal groups(P=0.055).

CONCLUSION: Bfocal and trifocal diffractive IOL can provide similar retinal image. Trifocal IOL can provide better itermediate visual acuity.