New preventative approach for negative dysphotopsia

PURPOSE: To evaluate whether positioning the intraocular lens (IOL) to decrease the entry of inferotemporal light would decrease the incidence of negative dysphotopsia. SETTING: Private practices, Boston and Chelmsford, Massachusetts, USA. DESIGN: Prospective randomized case study. METHODS: Patients had cataract surgery with implantation of either a silicone IOL inferotemporally or vertically (randomly assigned) or a 1-piece acrylic IOL with the optic haptic junction inferotemporally or vertically (randomly assigned). Other patients received acrylic IOLs bilaterally and inferotemporally without randomization. Patients were asked about negative dysphotopsia symptoms postoperatively. Data were analyzed using the z test and a chi-square test for comparing the incidence of negative dysphotopsia between the 3 groups. RESULTS: The study comprised 305 patients (418 eyes). A silicone IOL was implanted inferotemporally in 39 eyes and vertically in 60 eyes. An acrylic IOL was implanted with the optic haptic junction inferotemporally in 163 eyes and with the junction vertical in 114 eyes. Forty-two eyes had bilateral inferotemporal implantation of an acrylic IOL. For the acrylic IOL on the first postoperative day, the incidence of negative dysphotopsia was smaller for the inferotemporal IOL orientation (6%) than in the control group (14%) (P = .026). The rate of persistent negative dysphotopsia decreased in both groups over time, and the difference 1 month after surgery was no longer statistically significant. The negative dysphotopsia rate for the silicone IOL was 0%. CONCLUSIONS: Positioning the optic haptic junction of an acrylic IOL inferotemporally resulted in a 2.3-fold decrease in the incidence of negative dysphotopsia after cataract surgery. When implanted in the vertical position, Acrylic IOLs seemed to lead to a higher incidence of negative dysphotopsia than silicone IOLs. (C) 2016 ASCRS and ESCRS