Among the various mechanisms the authors think most common is tangentional traction force by the vitreal cortex immediately anterior to the foveal area, preceding a vitreous detachment. A discussion follows on the pros and cons of abstention or treatment.for fear of the latter produces a drop of visual acuity. As regards the criteria for surgical indication these are the following: 1) Presence of macular hole, stages 3 or 4 of Gass' classification. 2) Uni or bilateral affection. 3) Time of evolution less than 12 months. 4) Visual acuity under 20. 5) Metamophosia or central scotoma. 6) Detached halo around the hole. 7) Absence of previous history of cystic macular oedema, diabetic retinopathy, exhudative senile macular degeneration or other maculopathies. In order to adequately evaluate these patients the clinical study should include, macular biomicroscopy, successive retinographies, angiofluoresceingraphy, scanning laser ophthalmoscope scotometry and ocular tension control. The operation is performed under local (retro) plus a sedative, vitrectomy under AVI visual control, dissection of the posterior hyaloid by means of a special cannula, excision of the dissected hyaloid by means of the vitreotomas, study of the peripheral retina, fluid-air exchange, introduction of autologous serum, SF 6 , post-operative dorsal decubitus at least 1 hour. During the night the patient should rest in prone or lateral decubitus and after that maintain the prone decubitus for 24 hours; after that this position should be kept 4 hours twice a day, avoiding dorsal decubitus for the risk of cataract. The results in 21 cases (24 eyes) are tabulated. The best results were obtained with small holes and whose duration had been under 6 months.