Thyroid-Associated Optic Neuropathy: A Case Report of Optic Neuritis Due to Autoimmune Hypothyroidism

Optic neuritis is an uncommon complication of autoimmune hypothyroidism, which is often referred to as thyroid-associated optic neuropathy (TAON).

The case features a 22-year-old Somali woman who had no previous medical conditions. She had sudden vision loss, mainly in her right eye. This was accompanied by joint discomfort, muscular weakness, headaches, and weariness. The clinical examination showed complete absence of light perception in the right eye and there was a relative afferent pupillary deficit, and the thyroid function tests indicated severe hypothyroidism with significantly high levels of thyroid-stimulating hormone (TSH) and low levels of free Triiodothyronine (T3) and Thyroxine (T4). The diagnosis of autoimmune hypothyroidism was confirmed by the presence of positive anti-thyroid peroxidase (anti-TPO) and anti-thyroglobulin antibodies. Treatment was promptly initiated with high-dose corticosteroids (methylprednisolone) and levothyroxine replacement medication. Subsequently, her field of vision and visual acuity, when corrected with the best possible lenses, showed a considerable improvement. Further assessments demonstrated the restoration of normal thyroid function and the complete remission of symptoms related to ocular neuritis, with no further instances of recurrence.

The present case emphasizes the crucial need of promptly identifying and handling TAON in order to achieve positive visual results. This highlights the need of taking into account autoimmune hypothyroidism as a potential cause of ocular neuritis. Additional study is necessary to clarify the exact pathophysiological pathways that link autoimmune hypothyroidism to inflammation of the optic nerve, as well as to investigate the most effective therapy strategies.