Electrophysiological assessment of nutritional optic neuropathy: a case report.

PURPOSE: To report an unexpectedly asymmetric, progressive nutritional optic neuropathy associated with vitamin A deficient optic canal hyperostosis in a 15-year-old female with a long history of a restricted diet. METHODS: We performed comprehensive ophthalmic assessments in a fifteen-year-old female with a long history of restricted eating who presented with suspected nutritional optic neuropathy, predominantly affecting the right eye vision. RESULTS: A review of computerised tomography and magnetic resonance imaging revealed bilateral optic canal hyperostosis likely associated with vitamin A deficiency. Electrodiagnostic tests and optical coherence tomography provided structure-function evidence of bilateral retinal ganglion cell dysfunction and notably revealed severe loss of temporal fibres in the left eye which showed cecocentral scotoma but normal visual acuity. Although selective damage of the papillomacular bundle has been well-documented in nutritional and toxic optic neuropathies, compressive optic canal hyperostosis secondary to nutritional deficiency has been rarely reported. CONCLUSIONS: Nutritional deficiencies are increasing in high-income countries and may be linked to the rise of gastrointestinal disorders, strict vegan and vegetarian diets and avoidant restrictive food intake disorder (ARFID) associated with conditions such as depression and autism spectrum syndrome (ASD). Our findings highlight the value of electrodiagnostic testing alongside imaging in complex nutritional optic neuropathies to help monitor, guide treatment and preserve remaining sight in a child.

Visual electrophysiology in the assessment of toxicity and deficiency states affecting the visual system.

Visual disturbance or visual failure due to toxicity of an ingested substance or a severe nutritional deficiency can present significant challenges for diagnosis and management, for instance, where an adverse reaction to a prescribed medicine is suspected. Objective assessment of visual function is important, particularly where structural changes in the retina or optic nerve have not yet occurred, as there may be a window of opportunity to mitigate or reverse visual loss. This paper reviews a number of clinical presentations where visual electrophysiological assessment has an important role in early diagnosis or management alongside clinical assessment and ocular imaging modalities. We highlight the importance of vitamin A deficiency as an easily detected marker for severe combined micronutrient deficiency.