Abstract: Objective  To observe the efficacy of YAG laser vitreolysis on vitreous Weiss ring. Design Retrospective case series. Participants 192 patients (218 eyes) complained of floaters because of vitreous floaters (Weiss ring) second to posterior vitreous detachment during the period of October 2004 to July 2013 in Xiamen Eye Center. Methods All the 218 eyes underwent Nd:YAG laser vitreolysis for vitreous Weiss ring and were followed up 3 to 36 months, average 12±3 months. Preoperative visual acuity, intraocular pressure, three mirror examination, slit lamp photography, eye B-mode ultrasound, panoramic laser photography, autofluorescence examination and fundus fluorescein angiography were performed to determine the location and size of Weiss ring in vitreous. According to the size, the Weiss rings were divided into grand central (＞4 mm, 19 eyes), central (2~4 mm, 80 eyes), small ring(<2 mm, 119 eyes), and all were treated by Nd:YAG laser (ZEISS, VISULAS YAGII or YAGIII, the single pulse mode, energy 5~10 mJ). The therapeutic effects were observed and evaluated according to the smyptoms completely disappeared, improved, or invalid. Main Outcome Measures  Effective rate, improving rate, complicatins. Results Individual patients with single treatment of total energy from 56 mJ to 2136 mJ, the average was (961 ± 354) mJ. A single treatment time: 4~31 minutes, average (18 ± 5.2) minutes. 166 eyes were treated once, twice in 35 eyes, and 3 times in 17 eyes. Symptoms disappeared completely in 182 eyes (83.49%)，in which the effective rate was 94.12 in the small ring, 77.50% in the central ring, and 42.11% in the grand central ring; improved in 32 eyes (14.68%), invalid in 4 eyes (1.83%). No direct laser damages such as induced vision or visual field damage, damage of lens, intraocular pressure increasing, retinal vascular lesions, RPE autofluorescence damage etc were appeared. Conclusion For the Weiss ring caused by vitreous floaters, in strictly selected indications, Nd:YAG laser vitreolysis therapy is a relatively safe and simple, fast means, especially in the small floater.

Key words: posterior detachment of vitreous；Weiss ring, floaters, Nd: YAG laser