Electrophysiologic responses were tested in a series of 20 patients undergoing vitrectomy for recent rhegmatogenous retinal detachment. Patients required intraocular tamponade using either liquid silicone (10 patients mostly with giant tears) or 20% SF6-air mixture (10 patients with posterior retinal breaks or associated vitreous haemorrhage). Similar responses were obtained in both the silicone and the gas-tamponaded eyes; these showed progressive recovery and electroretinogram throughout the 6-month follow-up period. The recovery was accelerated by either absorption of the gas bubble or by the removal of liquid silicone.