Wilbrand's knee: does it exist?
OBJECTIVE
In 1904, Hermann Wilbrand reported that nasal ON fibers form a loop into the contralateral ON, subsequently referred to as Wilbrand's knee. He had further theorized that a lesion affecting Wilbrand's knee would develop a distinct visual field defect characterized by an ipsilateral central scotoma with a contralateral superotemporal visual field defect. We present clinical evidence that disputes the existence of Wilbrand's knee.


METHODS
A retrospective analysis of 3 patients whose ONs were divided at the ON-chiasm junction is presented. Two patients had an ONS meningioma and the other patient had sarcoidosis of the ON. Resection of the lesion and the ON up to the nerve-chiasm junction was done to prevent the disease from extending into the OC and the contralateral ON. The patients had detailed neuro-ophthalmologic evaluations preoperatively and postoperatively.


RESULTS
After the resection of the ON at the ON-chiasm junction in the 3 patients, junctional scotoma could not be detected by visual perimetry.


CONCLUSIONS
No clinical perimetric evidence was found to support the existence of Wilbrand's knee in the anterior visual pathway.
Lee
Joung H
JH
Department of Neurosurgery, The Cleveland Clinic Foundation, Cleveland, OH 44195, USA. leej@ccf.org
Tobias
Samuel
S
Kwon
Jeong-Taik
JT
Sade
Burak
B
Kosmorsky
Gregory
G
D000328:Adult; D001284:Atrophy / Q000473:pathology / Q000503:physiopathology; D001369:Axons / Q000502:physiology / Q000648:ultrastructure; D018450:Disease Progression; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008579:Meningioma / Q000150:complications / Q000473:pathology / Q000503:physiopathology; D008875:Middle Aged; D019635:Neurosurgical Procedures; D009897:Optic Chiasm / Q000473:pathology* / Q000503:physiopathology*; D009900:Optic Nerve / Q000033:anatomy & histology / Q000473:pathology* / Q000503:physiopathology*; D019574:Optic Nerve Neoplasms / Q000150:complications / Q000473:pathology / Q000503:physiopathology; D012189:Retrospective Studies; D012507:Sarcoidosis / Q000150:complications / Q000473:pathology / Q000503:physiopathology; D012607:Scotoma / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D016896:Treatment Outcome; D015354:Vision, Low / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*