In six human volunteers, serial electroretinograms (ERGs) were performed over five minutes at intraocular pressure artificially elevated with a suction cup. Compared to the base line ERG, there was no decrease in b-wave amplitude unless intraocular pressures approached or exceeded diastolic ophthalmic artery pressure, as determined by suction cup ophthalmodynamometry. Although reduced severely, the b-wave was not completely obliterated within five minutes, even at intraocular pressures above the mean ophthalmic artery pressure and in some cases above systolic artery pressure.
Sipperley J, Anderson DR, Hamasaki D. Short-Term Effect of Intraocular Pressure Elevation on the Human Electroretinogram. Arch Ophthalmol. 1973;90(5):358-360. doi:10.1001/archopht.1973.01000050360004