YAG Laser Treats Symptomatic Vitreous Floaters

Ricki Lewis, PhD

October 20, 2017

YAG laser vitreolysis effectively treated symptomatic vitreous floaters, according to a report published in the September issue of JAMA Ophthalmology.

Posterior vitreous detachment occurs in 65% of patients aged 65 years or older. It may be associated with accumulation of fibrous tissue into a Weiss ring, which hovers above the optic nerve and casts shadows onto the retina, producing large floaters in the visual field.

Management options for patients whose floaters affect quality of life are observation and education, single-incision pars plana vitrectomy, or YAG laser vitreolysis. However, only a few ophthalmologists worldwide perform YAG vitreolysis, and studies are limited.

Chirag P. Shah, MD, MPH, and Jeffrey S. Heier, MD, both from Ophthalmic Consultants of Boston, Massachusetts, conducted a masked, sham-controlled randomized clinical trial at their center that included 52 patients (35 women and 17 men), followed from March 25, 2015, through August 3, 2016. Thirty-six patients received YAG laser vitreolysis to the eye with the most floaters, and 16 underwent sham vitreolysis.

Before treatment, patients had Weiss ring floaters resulting from posterior vitreous detachment documented with B-scan, optical coherence tomography, and clinical observation, for at least 6 months; reported symptoms as debilitating; and had Weiss rings at least 3 mm from the retina and 5 mm from the posterior lens capsule of the crystalline lens. For the treated group, mean duration of symptomatic floaters was 6.7 years, and for the sham group, it was 5.0 years. Laser power began at 3 mJ and was raised until gas bubbles formed, indicating vaporization of the Weiss ring.

Clinical examinations evaluated participants after surgery at 1 week and 1, 3, and 6 months. Primary outcomes at 6 months included subjective percentage improvement and results of three evaluations: a 10-point visual disturbance score, a 5-level qualitative scale, and the National Eye Institute's Visual Functioning Questionnaire.

"The YAG group self-reported significantly greater improvement (54%) compared with sham controls (9%) (difference, 45%; 95% [confidence interval (CI)], 25%-64%; P < .001)," the authors write. The treated group also reported greater improvement in the 10-point visual disturbance score (3.2) compared with the sham group (0.13; difference, −3.0; 95% CI, −4.3 to −1.7; P < .001). The observation that some sham-treated patients reported improvement suggests a placebo effect or resolution of symptoms with time, according to the authors.

For the 5-level qualitative scale, 19 of the 36 treated patients (53%) reported symptoms significantly or completely better compared with none among the sham group (difference, 53%; 95% CI, 36%-69%; P < .001).

The treated group also did better on the National Eye Institute's Visual Functioning Questionnaire, reporting significantly improved general vision (69.4 vs 53.1; P = .04) and peripheral vision (94.4 vs 82.8; P = .04) and fewer role difficulties (93.1 vs 75.8; P < .001) and dependency on others (98.8 vs 93.2; P = .03) than the sham group at 6 months.

No significant adverse events were reported. "The YAG group reported numerous improvements 6 months after treatment, including in near and distance activities and mental health," the researchers report.

Limitations of the study are small sample size and short follow-up period.

"Our study was the first randomized controlled trial which included a select group of patients with symptomatic Weiss ring floaters from a posterior vitreous detachment. We reported a broad range of satisfaction after YAG vitreolysis, ranging from 0% to 100%," Dr Shah told Medscape Medical News.

In an accompanying invited commentary, Jennifer I. Lim, MD, the Marion H. Schenk Chair and professor of ophthalmology and director of the retina service at the University of Illinois at Chicago, cautions that the study does not demonstrate safety of the procedure. "Longer term follow-up is needed to determine whether there is an increased risk of retinal tear," she told Medscape Medical News.

Dr Lim added that YAG laser vitreolysis for the treatment of Weiss rings is not widely used. "If people were to use this treatment, then they would best apply the same inclusion criteria as was used in this study: symptomatic Weiss rings. At this time, I do not advocate this treatment until further work is performed."

Dr Shah agreed. "We need at least one large multicentered clinical trial powered to determine the rates of known adverse effects of YAG vitreolysis, such as retinal detachment, cataract formation, glaucoma, and retinal damage. The evolution of YAG vitreolysis has been unusual, with no clinical trial data preceding the performance of this procedure by ophthalmologists. The lack of data, coupled with the commercialization of the procedure, has led to the controversy surrounding YAG vitreolysis. More studies will help us better understand this procedure."

The authors have disclosed no relevant financial relationships. Dr Lim reported receiving funding for teaching a vitrectomy wet laboratory from Alcon.

JAMA Ophthalmol. 2017;135:918-923. Article abstract, Commentary extract

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