METHODS: Retrospective study. Totally 112 patients(130 eyes)were diagnosed with vitreous opacity were included and treated with laser vitreous ablation in our hospital from May 2018 to January 2020. All patients were performed the laser treatment for vitreous ablation and divided into groups A and B by different laser types. Group A(60 patients, 70 eyes)underwent Ultra Q:YAG vitreous ablation, and group B(52 patients, 60 eyes)underwent traditional Nd:YAG laser treatment. Then, we divided subgroups by the morphology of vitreous floaters. Subgroup A1(45 patients, 52 eyes)and subgroup B1(30 patients, 38 eyes)both with the morphology of Weiss ring, floccule and dense membrane; Subgroup A2(15 patients, 18 eyes)and subgroup B2(22 patients, 22 eyes)with the morphology of filiform and mesh. We observed the difference of frequency and visual improvement by patients compared to baseline.

RESULTS: BCVA: There was no significant difference between groups A1 and A2, groups B1 and B2, group A and group B at baseline(P>0.05). After treatment, there were statistically significant differences in BCVA between group A and group B at 2wk and 1mo. There were statistically significant differences between group A1 and group A2 at 1, 6 and 12mo(P=0.019, 0.042, <0.001). The effect of the laser treatment was significantly different between the two groups, group A was better than group B(P=0.006), group A1 was significantly better than that in group A2(P<0.001). Compared to traditional Nd:YAG laser, Ultra Q:YAG laser requires less frequency of laser treatment(P<0.001), and had no significant relationship with vitreous opacity(P>0.05).

CONCLUSION: Ultra Q:YAG is easier to operate, safer and has better subjective symptom improvement than traditional Nd:YAG laser treatment of vitreous floaters, especially for the patients with Weiss ring, floccule and dense membrane.