Limited Effect of Laser Treatment on Eye Floaters

SAN DIEGO — Laser treatment for eye floaters fell short of expectations, as the intervention improved patient-perceived floater burden but not intraocular pressure (IOP) or visual acuity, a retrospective study showed.

Following as many as four Nd:YAG-laser vitreolysis procedures, mean IOP actually increased slightly from 14.2 to 15.3 mm Hg and the logMAR (minimum angle of resolution) declined from 0.14 at baseline to 0.1. Patients’ perception of floater burden decreased from 8.25 to 5.25 on a scale of 1-10.

A majority of patients reported either mild or no overall improvement at the end of treatment. Individual vision factors affected by floaters also did not change or worsened slightly, reported Francesca A. Kahale, MD, of Mass General Brigham in Boston, during the American Society of Cataract and Refractive Surgery meeting.

“Even though it was only partially effective, there was a significant decrease in patient-reported floaters lasting beyond 6 months after laser treatment,” said Kahale. “So, it could be worth offering vitreolysis as a safe first-time treatment for burdensome floaters. Definitely discuss the risks and benefits with patients, especially with respect to setting realistic expectations.”

A small subgroup of patients with floaters probably does respond to laser vitreolysis, but that subgroup has yet to be identified, said Jerry Sebag, MD, of the University of California Los Angeles and Doheny Eye Institute in Pasadena, during a discussion that followed the presentation.

“To date, there have been no definitive studies showing efficacy of YAG laser vitreolysis,” he said. “In several attempts to review the literature and find any evidence, they’ve all failed. The National Institute of Standards and Excellence in the United Kingdom has banned, as of October of last year, the use of YAG vitreolysis to treat floaters except as part of an IRB-approved clinical research protocol and only if performed by specialists.”

Floaters are a common entoptic phenomena associated with vitreous opacities, Kahale noted in her introduction to the study. They are highly prevalent and associated with advanced age, myopia, and diabetes. Recent studies have suggested that floaters are more bothersome to patients than previously recognized. Current treatment options include observation and patient education, YAG laser vitreolysis, and pars plana vitrectomy.

To continue investigation of laser vitreolysis for floaters, Kahale and colleagues reviewed records of patients who had been evaluated for presence of chronic floaters and symptomatic opacities for more than 6 months and floater location greater than 2 mm from the retina and greater than 5 mm from the lens.

The chart review focused on visual acuity, IOP, and treatment details. Additionally, patients completed a satisfaction questionnaire at least 6 months after completing treatment for floaters. Data analysis included 20 patients who completed the satisfaction questionnaire. The primary outcomes were change in IOP, change in distance visual acuity, and burden of floaters.

Baseline characteristics showed that the patients had an extended history of floaters, as more than 90% reported a symptom duration of at least 2 years. Most patients had multiple dispersed small floaters or at least one large floater and multiple small ones, all centrally located.

The most commonly reported vision disruptions associated with floaters were near vision (74%), distance vision (52%), and bright light (48%). Activities most often affected by floaters were reading, driving, and working on a computer (25-30%). A majority of patients (60%) said they could perform all regular activities.

The patients received an average of 2.27 laser treatments. Most patients reported mild or moderate discomfort during the procedures (mean of 3.46 on a scale of 1-10).

The results showed that laser vitreolysis had no significant effect on IOP (P=0.39) or distance visual acuity (P=0.63). The pre- to post-treatment difference in patient-perceived impact on floater burden did achieve statistical significance (P<0.0001).

When asked to rate the improvement in floaters from baseline, 35% of patients said they had partial or significant improvement, and 9% had complete resolution. A majority (52%) of patients reported no or mild improvement, while 4% said the condition had worsened. For individual aspects of vision affected by floaters, patients noted no change in dim light vision or color vision and modest improvement in near vision, distant vision, and bright light.

Despite the mixed results with laser treatment, three fourths of the patients said they would recommend laser vitreolysis to a friend.