Date of Award
Master of Science in Biomedical Engineering - (M.S.)
Biomedical Engineering Committee
Andrew Ulrich Meyer
David S. Kristol
Edward Joseph Haupt
No one knows why Primary Open Angle Glaucoma sufferers can detect their glaucoma induced blindspots by monocularly fixating on a mark in the center of a screen of television snow. An attempt was made to determine which of two pathways from retina to lateral geniculate nucleus is more involved in the detection of the blindspots. Previous studies demonstrated that the large diameter axon, magno cellular pathway is maximally stimulated by 30 Hertz high contrast black-white patterns. The small diameter axon, parvo cellular pathway is known from past research to be maximally stimulated by 12 Hertz red-green counterphase patterns. It was found that patients when viewing a black-white noise presentation (snow) could more accurately determine glaucoma induced blindspots than when viewing a 5 Hertz red-green counterphase pattern. The possible presence of visual pathway fiber damage in the patients was indicated by subnormal results from a spatial frequency test that utilized a neutral density filtered Visitech Chart.
Favis, Rey, "Slow, red-green counterphase (PARVO) and fast, black-white MAGNO) snow in the detection of scotomata in primary open-angle glaucoma" (1992). Theses. 2253.