The aim of this study was to evaluate the clinical outcomes of asymmetric segmented refractive multifocal intraocular lens (IOL) and trifocal diffractive IOL for presbyopia correction.

Retrospective cohort study. 57 patients (57 eyes) with age-related cataract diagnosed at the Cataract Center of Aier Eye Hospital in Chengdu from November 2016 to June 2018 who undergoing phacoemulsification combined with IOL implantation were selected as study subjects. There were 28 male patients (28 eyes) and 29 female patients (29 eyes) with the average age of (63.3±5.5) years-old. They were divided into two groups according to the type of IOL implanted: the regional refraction group and the diffraction trifocal group. The uncorrected distance visual acuity (UDVA), uncorrected Intermediate visual acuity (UIVA), uncorrected near visual acuity (UNVA), best corrected distance visual acuity (BCDVA) of naked eye were measured and recorded. Optical quality analysis system Ⅱ(OQAS Ⅱ) was used to evaluate the visual quality, including the objective scatter index (OSI), modulation transfer function cut off (MTF cutoff), strehl ratio (SR) and contrast vision. The score was based on the VF-14 scale, and the rate of near deoscopy, adverse visual disturbance and quality of life were investigated by questionnaire. The measurement data are expressed by mean±standard deviation. Age, ocular axis, corneal astigmatism, implantation of IOL diopter, preoperative UDVA, preoperative BCDVA, postoperative OSI, MTF cutoff, SR, and VF-14 scores of two groups patients were analyzed by independent sample t test. The median and quartile interval was used for UDVA, UIVA, UNVA, BCDVA and contrast visual acuity. Three months after the operation, the analysis of UDVA, UIVA, UNVA, BCDVA, contrast vision in two groups of patients was performed by Mann-Whitney U test.

The spherical diopter after surgery in asymmetric segmented refractive group and trifocal diffractive group was -0.75 D to + 0.50 D and -0.50 D to+ 1.00 D and the cylindrical diopter was 0.00 D to -0.75 D and 0.00 D to -1.00 D, respectively. There is no significant difference in the proportion of spherical diopters between -0.50 D to+ 0.50 D and cylindrical diopters between -0.75 D to-1.00 D in two groups (χ²=0.000, 0.459; P>0.05). Postoperative UDVA, UIVA, UNVA and BCDVA in segmented refractive group were 0.10(0.00, 0.10), 0.20(0.20, 0.20), 0.20(0.10 , 0.20), 0.00(0.00, 0.10); and those of trifocal diffractive group were 0.05(0.00, 0.10), 0.20(0.10, 0.20), 0.10(0.10, 0.20), 0.00(0.00, 0.05), respectively. There was no significant difference in UDVA, UNVA, BCDVA between two groups at 3 months after surgery (Z=-0.169, -1.265, -1.410; P>0.05). Trifocal diffractive group had better UIVA than asymmetric segmented refractive group (Z=-2.708, P<0.05). Postoperative OSI, MTF cutoff, SR in segmented refractive group was (1.9±0.7), (24.755±7.751) c/deg, (0.126±0.029) and in trifocal diffractive group was (1.6±0.7), (35.813±9.984) c/deg, (0.195±0.083). There was no statistically difference in OSI between two groups (t=1.959, P>0.05), and there were significant statistical differences in MTF cutoff and SR (t=-5.419, -4.822; P<0.05). OV 100%, OV 20%, and OV 9% in segmented refractive group was 0.70(0.60, 0.90), 0.50(0.40, 0.60), 0.30 (0.20, 0.30) and those of the trifocal diffractive group was 1.20(0.95, 1.50), 0.70(0.60, 0.90), 0.50(030, 0.70) with significant statistical difference between them(Z=-4.882, -4.829, -3.676; P<0.05). VF-14 scores of segmented refractive group and trifocal diffractive group were (94.39±4.74) and (96.86±3.63) with non-significant difference between them (t=-0.075, P>0.05). No difference was found between two groups in near-distance spectacle independence rate and incidence of glare (χ²=0.181, 0.002; P>0.05). But statistical difference was found in the incidence of halo between segmented refractive group (3.57%) and trifocal diffractive group (27.59%) (χ²=4.505, P<0.05).

The two presbyopia-corrected IOLs could provide good full range of clear vision for patients with age-related cataracts. Both of them have good predictability of refractive power. Trifocal diffractive IOL had a better objective retinal image quality.