Semaglutide-linked vision loss may involve hidden optic nerve spots and long-term dehydration

A 1.9 L decline in total body water was observed over 7 weeks in a patient with semaglutide-associated non-arteritic anterior ischaemic optic neuropathy.

• A 28-year-old man with type 2 diabetes developed right non-arteritic anterior ischaemic optic neuropathy 4-5 months after starting semaglutide.
• Multimodal imaging confirmed the diagnosis of non-arteritic anterior ischaemic optic neuropathy and identified bilateral buried optic disc drusen.
• The affected eye was shorter in length compared to the fellow eye, which was highly myopic and longer.
• Preserved fat mass and a stable extracellular-to-total-body-water (ECW/TBW) ratio were noted despite the decline in total body water.
• A hypothesis-generating 'two-hit' model is proposed, suggesting that anatomical susceptibility and sustained hypohydration may together trigger non-arteritic anterior ischaemic optic neuropathy.
• Heightened clinical awareness may be warranted, and prospective studies are needed to further explore these associations.

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