[Changes in retinal electrical response due to different size of experimental retinal detachment]

To investigate the influence of the size of detachment to function of the detached retina, transretinal ERG (TR-ERG) was recorded from experimentally detached retina. Retinal detachment 4 or 8 mm in diameter was made by injecting sodium hyaluronate in the subretinal space. The TR-ERG was recorded for two hours from the detached retina by a double barreled microelectrode of which a longer tip entered into the subretinal space of the detached retina while a shorter one remained in the vitreous. Vitreal ERG (VERG) was simultaneously recorded between the shorter electrode and a scleral electrode. The b-wave amplitude of the TR-ERG recorded from the retina with 4 mm detachment decreased two hours after detachment, whereas the b-wave recorded from the retina with 8 mm detachment remarkably decreased 30 min after detachment and was stable up to two hours. There were no significant differences in amplitudes of VERG b-waves between 4 and 8 mm detachments during the experimental course. Less extensively detached retina maintained its function to a greater degree than the largely detached retina. The volume of the subretinal space may influence the viability of the detached retina by changing the concentration of nutrients.