The aim of the surgery is to reduce and stabilize the macular oedema. The surgery has to be atraumatic and complete, with a big rhexis including the whole macular area, to the optic center in nasal, the vascular arcades and the temporal vascular raphe.

An uncomplete/only partial removal, particularly in temporal, will induce bad post-operative results, that are the origin of the often heard criticism about the technique.