The Neuro-Ophthalmology of Tuberculosis

Tuberculosis (TB) is a global health concern and central nervous system (CNS) TB leads to high mortality and morbidity. CNS TB can manifest as tubercular meningitis, tuberculoma, myelitis, and arachnoiditis. Neuro-ophthalmological involvement by TB can lead to permanent blindness, ocular nerve palsies and gaze restriction. Visual impairment is a dreaded complication of tubercular meningitis (TBM), which can result from visual pathway involvement at different levels with varying pathogenesis. Efferent pathway involvement includes cranial nerve palsies and disorders of gaze. The purpose of this review is to outline the various neuro-ophthalmological manifestations of TB along with a description of their unique pathogenesis and management. Optochiasmatic arachnoiditis and tuberculomas are the most common causes of vision loss followed by chronic papilloedema. Abducens nerve palsy is the most commonly seen ocular nerve palsy in TBM. Gaze palsies with deficits in saccades and pursuits can occur due to brainstem tuberculomas. Corticosteroids are the cornerstone in the management of paradoxical reactions, but other immunomodulators such as thalidomide and infliximab are being explored. Toxic optic neuropathy caused by ethambutol necessitates careful monitoring and immediate drug discontinuation. Cerebrospinal fluid diversion through ventriculo-peritoneal shunting may be required in patients with hydrocephalus in stage I and II of TBM to prevent visual impairment. Early diagnosis and prompt management are crucial to prevent permanent disability. Prevention strategies, public health initiatives, regular follow-up and timely intervention are essential in reducing the burden of CNS TB and its neuro-ophthalmological complications.

Case Report: Late Sequela of a Muslinoma Involving the Optic Chiasm

An 84-year-old woman presented with 3 months of vertical binocular diplopia and difficulty reading at near. She had a history of bilateral ophthalmic artery aneurysm repair involving use of muslin in the 1990s. The patient then developed bitemporal hemianopsia secondary to muslin-induced inflammation ("muslinoma") extending to the optic chiasm, which required surgical decompression. She had a persistent bitemporal hemianopsia but was stable for two decades after surgery. In 2017, the patient re-presented with double vision. Exam showed a non-paretic diplopia due to a small angle comitant right hypertropia attributed to the retinal hemi-field slide. Repeat imaging showed no new aneurysm or recurrent muslinoma. This case had originally been reported two decades ago and represents the longest duration of recurrent symptoms from muslin-related optochiasmatic arachnoiditis in the English language ophthalmic literature. Clinicians should be aware of the potential of delayed and recurrent symptoms or signs years or even decades after muslin wrapping of aneurysms.