Auditory evoked phosphenes in optic nerve disease

Area of Science:

• Ophthalmology
• Neurology

Background:

• Optic neuropathy can manifest with diverse and unusual sensory symptoms.
• Phosphenes, or visual disturbances of light flashes, are typically associated with retinal or optic nerve dysfunction.

Purpose of the Study:

• To describe a unique case series of optic neuropathy patients experiencing sound-evoked phosphenes.
• To investigate the characteristics and potential management of this specific visual phenomenon.

Main Methods:

• Case series describing five patients with optic neuropathy (four vascular, one demyelinating).
• Detailed patient interviews focusing on the nature, triggers, and impact of visual symptoms.
• Observation of symptom presentation and response to pharmacological intervention.

Main Results:

• All five patients reported bright light flashes (phosphenes) in affected eyes.
• Phosphenes were consistently evoked by sudden, unexpected sounds.
• Eye movement alone did not trigger the phosphenes.
• The symptom interfered with sleep in all patients.
• Phenytoin, an anticonvulsant, reduced phosphene frequency and intensity in one patient.

Conclusions:

• Sound-evoked phosphenes can be an unusual symptom in patients with optic neuropathy.
• This phenomenon highlights a potential link between auditory stimuli and visual pathways in certain neuropathic conditions.
• Further research is warranted to understand the underlying mechanisms and explore therapeutic options for sound-evoked phosphenes.