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Objectives: To describe the hallucinations occurring as a result of a macular hole in each eye and to investigate the neural basis. Methods: Psychophysical observations including sketches of the hallucinations calibrated for size. Results: All the hallucinations were of the geometric (patterned) type and lasted for only a few days. Conclusions: The observations can be explained on the basis of a “deafferentation” model, which is described in some detail. It is proposed that the hallucinations result from activation of the “blobs” of area V1 and the “stripes” of area V2 in the visual cortex. A theory is proposed to account for the disappearance of the hallucinations by a “filling in” mechanism.

To characterise the clinical findings and natural history of anterior visual pathway compression by dolichoectatic intracranial vessels.A retrospective case review of patients evaluated in an outpatient neuro-ophthalmology clinic.10 patients with this condition were identified. Dolichoectatic compression was confirmed by magnetic resonance scanning in all patients. The average age at presentation was 70.6 years and eight of the 10 were female. The carotid artery was involved in seven patients and the basilar in three. Patterns of visual loss varied depending on the site of compression. The most common pattern in patients with optic neuropathy was nasal field loss. In most patients visual loss showed little progression over time. Over an average follow up interval of 2.8 years, progressive visual loss was documented in only three cases. In one of these, neurosurgical intervention was undertaken with subsequent improvement of vision.Visual loss resulting from compression of the visual pathways by dolichoectatic arteries is usually mild and only slowly progressive. Most patients are elderly, with other forms of vascular disease. Conservative management is thus usually appropriate in this disorder. In occasional cases with more rapid progression, surgical intervention may be beneficial.