Evaluation of a new device to treat negative dysphotopsia

Purpose: To evaluate the efficacy and safety of Negative Dysphotopsia (ND) Ring implantation for treating and preventing ND. Setting: Multicentric tertiary eye hospitals. Design: Prospective interventional cohort study. Methods: 22 patients with ND were enrolled. Eyes with other ocular structural pathologies (corneal, macular, optic nerve head, retinal, neuro-ophthalmological) were excluded. In 15 eyes, the ring was implanted to treat ND (therapeutic group), and in 7 eyes, it was implanted during cataract surgery of the fellow eye as a prophylactic measure (prophylactic group) to prevent the occurrence of ND. Preoperative evaluation included video recording of the patients' complaints aside complete eye examination. Postoperatively, patients were interviewed to confirm resolution of complaints related to ND. The intraoperative difficulties and postoperative adverse events were recorded. A minimum follow-up of 1 year was completed for all eyes. Results: In the therapeutic group, 14 of 15 eyes (93.3%) patients reported complete resolution of ND on the first postoperative day while 1 patient reported persistence of a smaller and lighter temporal shadow. No ND was reported by any patient in any of the 7 eyes treated prophylactically. No significant adverse intraoperative event was recorded; however, vitreous upthrust was noted in 2 of 22 eyes (9.0%). No permanent drop in visual acuity was recorded in the therapeutic group. Conclusions: ND Ring implantation was an easy, safe, and effective approach for both treating and preventing ND.