Orbital Apex Syndrome Secondary to Herpes Zoster Ophthalmicus: A Case of Irreversible Optic Nerve Damage.

Herpes zoster ophthalmicus (HZO) arises because of the reactivation of latent varicella-zoster virus (VZV) infection in the trigeminal nerve ganglion and typically presents with ocular manifestations. However, infrequent neurological complications can also be seen. Rarely occurring, orbital apex syndrome presents itself as a severe complication of HZO, characterized by the involvement of multiple cranial nerves and vascular structures within the orbital apex. A 70-year-old male patient being followed for HZO developed orbital apex syndrome after 14 days of treatment, resulting in ophthalmoplegia, vision loss, and significant morbidity. Clinical diagnosis was confirmed by magnetic resonance imaging of the orbit. The treatment involved a combination of systemic steroid and antiviral therapy, resulting in a favorable resolution of ophthalmoplegia within six months. However, optic-neuropathy-induced vision loss was irreparable. Early recognition, antiviral therapy, and multidisciplinary management are crucial in preventing permanent visual impairment and neurological deficits associated with this uncommon complication.