Comparison of medium and long term visual quality between regional refractive multifocal intraocular lens implantation and unifocal intraocular lens implantation

Objective

To observe the clinical effect of medium and long term visual quality after regional refractive multifocal intraocular lens (MIOL) implantation and compared with that of single focal intraocular lens (SMOL) implantation.

Methods

A cohort study was conducted with 108 patients (141 eyes) who had undergone MIOL and SIOL implantation in First Affiliated Hospital of Zhengzhou University from August 2016 to August 2017.According to the implanted IOL, the patients were divided into the MIOL group (55 patients 76 eyes) and the SIOL group (53 patients 65 eyes). At 2 years after operation, the parameters of uncorrected far, intermediate and near vision, as well as corrected distant vision were assessed; the spherical equivalen was checked; the defocus curve of the operation eye was drawn; the high order aberrations (HOAs), Strehl ratio and modulation transfer function (MTF) were measured by i-Trace visual quality analyzer; contrast sensitivity of eyes was evaluated by a CSV-1000 contrast sensitivity instrument; visual quality between the two groups was compared by using the Chinese version of the American questionnaire on quality of Life after MIOL.This study was approved by the Ethics Committee of the First Affiliated Hospital of Zhengzhou University.Written informed consent was obtained from each patient prior to any medical examination.

Results

The uncorrected intermediate and near visual acuity in the MIOL group was better than that in the SIOL group, with statistically significant difference(both at P<0.05). Two years after operation, the average defocus curve showed that there were two peaks at 0.0 D and -3.0 D in the MIOL group, and formed a wide platform between 0.0 and -3.0 D, and the downward trend was gentle.Under the pupil diameter of 5 mm, HOAs, coma, trefoil and secondary astigmatism in the MIOL group were higher than those in the SIOL group (all at P<0.05). Strehl ratio in the MIOL group was significantly lower than that in the SIOL group, with statistically significant difference (P<0.05). Under the pupil diameter of 5 mm, MTF values of spatial frequencies of 5, 10, 15, 20, 25 and 30 c/d in the MIOL group were slightly lower than those in the SIOL group, without statistically significant differences (all at P>0.05). There was no significant difference in contrast sensitivity (3, 6, 12 and 18 c/d) between the two groups under photopic or mesopic conditions and with or without glare (all at P>0.05). The proportion of glasses removed in the MIOL group was 98.18%, which was significantly higher than that in the SIOL group (52.83%) by questionnaire (χ²=30.37, P<0.01). The incidence of visual interference symptoms, such as glare and halo was 7.27% (4/55) in the MIOL group and 1.89% (1/53) in the SIOL group, respectively, with no statistically significant difference (χ²=0.76, P=0.382). The satisfaction scores of vision at near distance vision, medium distance vision and overall visual acuity in the MIOL group were higher than that in the SIOL group, with statistically significant differences (all at P<0.05).

Conclusions

Compared with SIOL implantation, regional refraction MIOL implantation can provide better and more stable mediate and near vision, a better contrast sensitivity, a lower incidence of optical interference and a higher postoperative satisfaction.

Multifocal intraocular lenses; Lens implantation, intraocular; Wavefront aberration; Modulation transfer function; Contrast sensitivity