To the Editor.
—In the January Archives (1983;101:94-97) Sossi and Anderson reported the results of an experiment on the mechanism of damage to cat optic nerve by intraocular pressure elevation of four hours, using the degree of axonal transport block as a measure of axonal injury. In some animals, BP was artificially lowered or raised to produce a wide range of tested IOP and mean BP. They sought to determine whether axonal injury is more closely correlated with absolute IOP (suggesting a mechanical effect) or more closely matches the perfusion pressure (mean BP—IOP), a result that would support the idea that the damage was vascular in cause.I admire both the care with which the experiment was performed and the large number of eyes studied; however, I reexamined the data given in the Figure and came to different conclusions from those drawn by the authors. First, I plotted
Quigley HA. Experimental Glaucoma Damage Mechanism. Arch Ophthalmol. 1983;101(8):1301-1302. doi:10.1001/archopht.1983.01040020303031