[Floating membranes]

Floating membranes are epiretinal membranes that spontaneously detach from the retina and float in the vitreous cavity.

We studied a series of nine patients with a spontaneous separation of a premacular membrane. The majority of these detached membranes were secondary to vitreomacular traction syndrome. In four patients, the presence of peripheral retinal tears treated in the past by laser photocoagulation were found. None of the patients had complete vitreoretinal detachment before progressing to floating membranes.

The separation of the membrane from the macular area occurred at the time of posterior vitreous detachment. The appearance of a bulky intravitreous floating body attached to the posterior vitreous cortex sometimes proved to be very awkward for vision, resulting in a vitrectomy in four patients for ablation of this large floating body. In five patients who were not operated, the presence of the membrane in the vitreous cavity was not responsible for significant functional disorders.

The epimacular membranes concerned in this series were not very symptomatic before their detachment. They seemed to be integrated within the context of vitreomacular traction syndrome. The most invalidating cases that required surgery were those where the separation of the vitreous cortex remained incomplete, leaving an opaque membrane floating with a little mobility in front of the macular area (three out of four cases).

The spontaneous detachment of a premacular membrane is an event that is quite seldom observed and generally follows the spontaneously favorable progression of vitreomacular traction syndrome.