Purchase this article with an account.
K.P. Kolostyak, F.N. Ross–Cisneros, A.A. Sadun; The Search for Wilbrand's Knee . Invest. Ophthalmol. Vis. Sci. 2006;47(13):801.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To determine the physical presence of Wilbrand's knee thought to be a human anatomic configuration in the optic chiasm which would explain the existence of junctional scotomas. Wilbrand's early work has been challenged by Horton as an artifact secondary to traction from optic nerve atrophy.
One normal adult human optic chiasm stored in 10% neutral buffered formalin was embedded in paraffin in the horizontal plane. Cross–sectional profiles of each nerve were also embedded. Sections were cut at 4 µm on a microtome and stained by Bielschowski and Bodian methods as well as immunostaining of neurofilaments. The sections were visualized using light microscopic methods. Since this patient had no prior ocular pathology, there was no optic atrophy to confound the results.
The optic nerves were, as expected, without atrophy. The optic chiasmal retinal ganglion cell fibers were well visualized, including the decussating nasal fibers. These decussating fibers did not bend anteriorly before joining the contralateral optic track. In short, Wilbrand's knee was not appreciated.
This study supports the recent work of J. Horton and his contention that previous histologic descriptions of Wilbrand's knee were subject to an artifact created by the longstanding atrophy from prior ocular enucleation puroposely chosen by Wilbrand as part tof his track tracing methodology. This atrophy in one optic nerve led to the bending of fibers decussating from the contralateral optic nerve.
This PDF is available to Subscribers Only