Interference with visual pathways is usually not caused by intracranial aneurysms. Aneurysms of the anterior communicating artery rarely produce visual symptoms and signs in spite of their proximity to the visual pathways. The reason may be that these aneurysms rupture and present with subarachnoid hemorrhage before becoming large enough to exert significant pressure on the chiasm or optic nerves. The visual symptoms would be presented as visual field defect or impaired vision. These can be explained as the result of direct compression of the optic pathways, ischemic changes in the visual pathways caused by severe vasospasm after subarachnoid hemorrhage, or intraocular pathology such as retinal hemorrhage. 2 cases of anterior communicating artery aneurysms associated with visual symptoms are presented with a brief review of literatures.
Aneurysm ; Arteries ; Intracranial Aneurysm* ; Optic Nerve ; Pathology ; Retinal Hemorrhage ; Rupture ; Subarachnoid Hemorrhage ; Visual Fields ; Visual Pathways

OBJECTIVES: To investigate the characteristics and objective assessment method of visual field defects caused by optic chiasm and its posterior visual pathway injury. METHODS: Typical cases of visual field defects caused by injuries to the optic chiasm, optic tracts, optic radiations, and visual cortex were selected. Visual field examinations, visual evoked potential (VEP) and multifocal visual evolved potential (mfVEP) measurements, craniocerebral CT/MRI, and retinal optical coherence tomography (OCT) were performed, respectively, and the aforementioned visual electrophysiological and neuroimaging indicators were analyzed comprehensively. RESULTS: The electrophysiological manifestations of visual field defects caused by optic chiasm injuries were bitemporal hemianopsia mfVEP abnormalities. The visual field defects caused by optic tract, optic radiation, and visual cortex injuries were all manifested homonymous hemianopsia mfVEP abnormalities contralateral to the lesion. Mild relative afferent pupil disorder (RAPD) and characteristic optic nerve atrophy were observed in hemianopsia patients with optic tract injuries, but not in patients with optic radiation or visual cortex injuries. Neuroimaging could provide morphological evidence of damages to the optic chiasm and its posterior visual pathway. CONCLUSIONS Visual field defects caused by optic chiasm, optic tract, optic radiation, and visual cortex injuries have their respective characteristics. The combined application of mfVEP and static visual field measurements, in combination with neuroimaging, can maximize the assessment of the location and degree of visual pathway damage, providing an effective scheme for the identification of such injuries.
Humans ; Optic Chiasm/pathology* ; Visual Pathways/pathology* ; Visual Fields ; Evoked Potentials, Visual ; Random Amplified Polymorphic DNA Technique ; Hemianopsia/complications* ; Vision Disorders/pathology* ; Optic Nerve Injuries/diagnostic imaging* ; Brain Injuries, Traumatic/diagnostic imaging*

This report presents a rare example of a bilateral congenital anophthalmos and an agenesis of the optic pathways. The MR imaging studies revealed that the eyeballs, optic nerves, optic chiasm, optic tracts and optic radiation were absent. The chromosomal examination was normal. Mild mental retardation was also observed. Apart from the rarity of the anophthalmos and the total absence of the optic pathways, no etiologic reason for this pathology could be detected, which makes this case more significant.
Abnormalities, Multiple/diagnosis ; Adult ; Anophthalmos/*complications ; Female ; Humans ; Magnetic Resonance Imaging ; Mental Retardation/complications ; Optic Chiasm/abnormalities ; Optic Nerve/abnormalities ; Visual Pathways/*abnormalities/pathology

BACKGROUNDWith conventional imaging methods only the morphous of the visual nerve fiber bundles can be demonstrated, while the earlier period functional changes can not be demonstrated. We hypothesized that diffusion tensor imaging (DTI) would demonstrated the whole optic never fiber bundle and visual pathway and the earlier period functional changes. The purpose of the present study was to evaluate the application of DTI technique in the demonstration of the whole optic never fiber bundle and visual pathway, and the influence of orbital tumors on them.

METHODSGE 1.5 T signa HD MR System, and the software package DTV2 were adopted. The total 45 subjects were enrolled, including 15 volunteers and 30 patients. All patients had ocular proptosis from minor to major. Seven patients had visual acuity decrescence.

RESULTSThe nerve fiber bundles, e.g. optic chiasma, optic tract and optic radiation in posterior visual pathway were well demonstrated in all cases. Wherein, the intact whole visual pathway fiber bundles were clearly revealed in 10 volunteers and 17 patients, and optic nerve was not wholly revealed in the rest of the subjects. Shift of optic nerve caused by compression and partial deformation were seen in 7 patients with orbital tumor. In 6 of 7 patients, DTI displayed significant abscise and deformation of visual nerve. Chi-square test indicated significant correlation between visual acuity decrescence and DTI visual nerve non-display.

CONCLUSIONSVisual nerve fiber bundles and the whole visual pathway were visualized in most of patients with DTI. It might be an effective method of providing imaging evidence for visual nerve fiber earlier period functional changes, and laid a foundation for the study in other cranial nerves.

Adult ; Aged ; Diffusion Magnetic Resonance Imaging ; methods ; Exophthalmos ; pathology ; Female ; Humans ; Male ; Middle Aged ; Optic Chiasm ; anatomy & histology ; pathology ; Optic Nerve ; anatomy & histology ; pathology ; Visual Pathways ; anatomy & histology ; pathology ; Young Adult

OBJECTIVETo investigate the association of microsurgical anatomy and growth of pituitary tumors with the recovery of visual pathway, and describe the intraoperative protection of the pituitary stalk and visual pathway.

METHODSA total of 113 patients undergoing pituitary tumor surgery were retrospectively analyzed, including 102 with visual disorder and 106 with pituitary dysfunction with the tumor size ranging from 1.9 to 6.8 cm. All the operations were performed via a transpterygoid approach or transfrontal approach.

RESULTSRadical resection of the tumors was performed in 86 cases, subtotal resection in 21 cases, and partial resection in 5 cases. After operation, 133 eyes showed vision improvement (77.8%), 29 showed no vision changes (17%) and 9 had deteriorated vision. Two patients died due to hypothalamic disorder and multiple organ failure.

CONCLUSIONThe arachnoid barrier between the pituitary tumor and visual pathway is an important structure for visual pathway protection during operation. Total separation of the tumor from the visual pathway allows total removal of the tumor. The preoperative localization and intraoperative identification of the pituitary stalk are critical for pituitary stalk protection.

Adenoma ; pathology ; surgery ; Adolescent ; Adult ; Aged ; Child ; Child, Preschool ; Female ; Humans ; Intraoperative Complications ; prevention & control ; Male ; Microsurgery ; adverse effects ; methods ; Middle Aged ; Neurosurgical Procedures ; methods ; Pituitary Gland ; pathology ; Pituitary Neoplasms ; pathology ; surgery ; Retrospective Studies ; Treatment Outcome ; Visual Pathways ; pathology ; Young Adult