[Biomicroscopic findings of premacular posterior vitreous]

The presence of vitreous gel in front of the macular area is still controversial. In order to understand the anatomy of the premacular vitreous, the posterior vitreous was observed biomicroscopically and slit-lamp photographs were taken in 100 eyes without posterior vitreous detachment. We defined the premacular vitreous as the lacuna seen when optically empty space, a demarcated oval shaped dark area without Tyndall phenomenon, was observed in front of the macula. Although the premacular vitreous showed liquefaction, the Tyndall-phenomenon, indicating the presence of formed vitreous gel, was observed in most cases. Premacular lacuna was observed in 3 cases with high myopia, and in one case with vitreoretinal degeneration syndrome. The bursa premacularis or premacular precortical vitreous pocket observed in autopsy eyes could barely be observed in living eyes.