Clinical observation on visual quality in patients implanted with monofocal and multifocal aspheric intraocular lenses

Abstract

To evaluate the visual quality in patients implanted with aspheric diffractive multifocal intraocular lens. Prospective nonrandomized controlled study. One hundred cataract eyes in 50 patients were included. Patients received AcrySof IQ ReSTOR IOL (SN6AD3) or AcrySof IQ IOL (SN60WF) implantation. The follow up period was 6 months. The mean of uncorrected distance visual acuity (UCDVA), best corrected distance visual acuity (BCDVA), uncorrected near visual acuity (UCNVA), best distance-corrected near visual acuity (BCNVA) and intermediate uncorrected visual acuity in patients with SN6AD3 and SN60WF was compared preoperatively and postoperatively in all patients. Photopic and mesopic contrast sensitivity function with and without glare were tested at 6 months after operation. Aberrations were recorded postoperatively. Subjective outcomes were assessed by VF-14 questionnaire. The chi-square test was applied to compare categorical variables and the paired-samples t test was used to compare the measure data. Postoperatively, there were no significant differences between groups in spherical equivalent (SE) (t = 0.233, P = 0.876), UCDVA (t = 1.018, P = 0.265) or BCNVA (t = 0.679, P = 0.501). The BCDVA in the monofocal IOL group was better than that in the multifocal IOL group (t = 2.388, P = 0.021). UCNVA improved remarkably after the implantation of multifocal IOL (t = 11.311, P = 0.000). The intermediate UCVA in the monofocal IOL eyes was butter than that in the multifocal IOL at 60 cm (t = 2.414, P = 0.020). The total aberration (F = 5.169, P = 0.041), total low grade (F = 4.973, P = 0.036) and total high grade total aberrations (F = 4.640, P = 0.048) were higher in the multifocal IOL group. There was no difference between these two groups in the defocus (F = 0.862, P = 0.358), astigmatism (F = 3.893, P = 0.052), spherical aberration (F = 1.743, P = 0.055), coma (F = 2.724, P = 0.105) and trefoil (F = 3.014, P = 0.109). Contrast sensitivity in eyes with multifocal IOL was lower than that in eyes with monofocal IOL, especially under mesopic conditions without glare at 6 c/d (t = 2.16, P = 0.041) at 3 c/d (t = 2.329, P = 0.029) and 6 c/d under mesopic conditions with glare (t = 2.087, P = 0.048). Most patients were satisfied with their IOL implantation. Percentage of patients wearing spectacle for distance vision were less than 4% in all groups. Percentage in patients wearing spectacle for near vision in SN60WF and SN6AD3 groups was 60% and 16%, respectively. Percentage of overall spectacle wear was 64% and 24% in patients wearing SN60WF and SN6AD3, respectively. On the questionnaire, patients in multifocal IOL group complained with double vision, trouble in night vision and halo; while patients in monofocal IOL group noted more about near blur. Compared with monofocal lenses, multifocal IOL provide greater depth of focus so that better near vision, higher percentage of spectacle independence and satisfactory visual function, are obtained but the contrast sensitivity decreases slightly.