By injecting dyes into both unfixed and formalin-fixed specimens J. Worst (1977) discovered and described pouch-like entities, which he named “cisterns''. He classified cisterns into three groups in the antero-posterior direction: circulus cisternalis retrociliaris, circulus cisternalis equatorialis, and circulus cisternalis petaliformis.
The bursa premacularis was first described by J. Worst in 1975 as a pear-like pouch located in front of the macular area.
The cisterna preoptica is a small pouch located in front of the optic nerve head, in the area previously referred to as the prepapillary area of Martegiani (1814).
