New information on the physiopathology and treatment of orbital volumes pathologies is described: 1) In post-enucleation or evisceration socket syndrome placing of synthetic material (HA-TCP) directly in the intraconal orbital fat can correct most of the symptoms. However the best approach is to prevent orbital volume deficiencies during first surgery using an implant large enough to allow a future prosthesis of a volume less than 2 mL. New procedures for placing the implant after enucleation or evisceration are described. 2) In proptosis related to Graves' orbitopathy relative indications are given for orbital decompression by removal of fat or bone.