I am researching the numbers of devices used to detect glaucoma which
are in operation both nationally in the U.S. and globally and, if
possible, the numbers sold each year. In particular, I am interested
in the numbers for Heidelberg Engineering's HRT II, Zeiss's OCT3, and a
device called GDx (I have not yet found the manufacturer for this
device). If you can either find this information or point me toward a
resource that would sell it to me, I would be most grateful.