Visual Quality Differences between Multifocal Intraocular Lenses with Near Additions of +3.00 and +2.50 Diopters

Abstract

Objective: To compare the visual quality of multifocal intraocular lenses (IOLs) with near additions of +3.00 and +2.50 Diopters (D). Methods: In this prospective clinical study, patients from the Eye Hospital, Wenzhou Medical University during May 2014 to December 2015 undergoing phacoemulsification were divided into two groups according to the type of multifocal IOLs used. The control group (24 patients, 32 eyes) received +3.00 D multifocal IOLs, and the trial group (28 patients, 33 eyes) received +2.50 D multifocal IOLs. Parameters including visual acuity, refraction, defocus curves, contrast sensitivity, objective optical quality, and a quality of life questionnaire were measured three months after surgery. Datas were analyzed using independent t tests and chi-square tests. Results: For the control and trial groups, the best corrected distance visual acuity (LogMAR) was 0.03±0.06 and 0.05±0.07 respectively (t=-1.179, P=0.228). The distance corrected intermediate visual acuity at 80 cm was 0.32±0.17 and 0.25±0.11 respectively (t=2.761, P=0.017). The distance corrected near visual acuity at 33 cm was 0.22±0.11 and 0.31±0.20 respectively (t=-4.188, P=0.019). The defocus curves of each group had two peaks. However, the curve between the two peaks of the trial group was smoother than the control group. The visual acuity of the trial group was better than the control group at the -1.50 D defocus level (t=2.103, P=0.038) and worse than the control group at -3.00, -3.50, and -4.00 D defocus levels (t=-3.183, -2.678, -3.33, P < 0.01). There were also no significant differences in contrast sensitivity at any spatial frequency under different lighting conditions. There were no significant differences in the modulated transfer function cut-off values or the objective scattering index values between the two groups. Finally, there were no significant differences in the overall satisfaction, independent spectacles ratio, or glare and halo between the two groups. Conclusions: There were no significant differences between the two multifocal IOLs at distance visual acuity, visual quality, overall satisfaction, or independent spectacles ratio. However, +2.50 D multifocal IOLs provided better intermediate vision and worse near vision than +3.00 D multifocal IOLs. Key words: phacoemulsification; visual quality; multifocal intraocular lenses