Optic Perineuritis Due to Tuberculosis

A 30-year-old man experienced subacute peripheral visual field loss with preserved central vision in his right eye. He was diagnosed with optic perineuritis due to tuberculosis. Optic perineuritis is an uncommon disorder and, at times, can be difficult to distinguish from optic neuritis. The differentiation can have significant impact on diagnostic testing and patient management.

Photo Essay Section Editors: Melissa W. Ko, MD Dean M. Cestari, MD Optic Perineuritis Due to Tuberculosis William B. Yates, MD, Simon Nothling, MD, Mitchell Lawlor, PhD, MD FIG. 1. Automated visual field testing of the right eye reveals peripheral constriction. Abstract: A 30-year-old man experienced subacute peripheral visual field loss with preserved central vision in his right eye. He was diagnosed with optic perineuritis due to tuberculosis. Optic perineuritis is an uncommon disorder and, at times, can be difficult to distinguish from optic neuritis. The differentiation can have significant impact on diagnostic testing and patient management. Journal of Neuro-Ophthalmology 2019;39:257-259 doi: 10.1097/WNO.0000000000000717 © 2018 by North American Neuro-Ophthalmology Society A 30-year-old man reported a 4-week history of reduced peripheral vision in his right eye associated with a dull ache with eye movement. Originally from Malaysia, he had lived in Australia for 14 years, with travel back to Malaysia twice during this time. He worked in the health care sector as a sleep scientist. Systems review was negative including absence of cough, rash, or joint pain. He took no medications regularly. Visual acuity was 20/20 in each eye, without dyschromatopsia, but a right relative Save Sight Institute (WBY, ML), Discipline of Ophthalmology, Faculty of Medicine and Health, University of Sydney, Sydney, Australia; Sydney Eye Hospital (WBY, ML), Sydney, Australia; and Retina & Macula Specialists (SN), Hurstville, Australia. The authors report no conflicts of interest. Address correspondence to William B. Yates, MD, Sydney Eye Hospital, 8 Macquarie Street, Sydney, Australia; E-mail: [e-mail] Yates et al: J Neuro-Ophthalmol 2019; 39: 257-259 afferent pupillary defect (RAPD) was present. There was no evidence of anterior chamber cells, flare or vitritis in either eye. Visual field testing (Humphrey 30-2) revealed peripheral field loss in the right eye (Fig. 1) with a normal field in the left eye. The right optic disc was swollen, but the remainder of the right fundus was normal, as was the left fundus (Fig. 2). MRI of the brain and orbits revealed enhancement of the orbital portion of the right optic nerve sheath (Fig. 3). Complete blood count and inflammatory markers were normal. The clinical and neuroimaging findings raised concern for granulomatous disease, and the decision was made to perform computed tomography of the chest. This revealed tree-in-bud/nodular opacities predominantly in the right apex suggestive of active tuberculosis (Fig. 4) (1). The patient underwent bronchoscopy and lavage, and bronchial acid fast bacilli culture revealed growth of Mycobacterium tuberculosis. The patient was negative for HIV and hepatitis B and C. He was prescribed isoniazid 300 mg/day, rifampicin 600 mg/day, and pyrazinamide 1750 mg/day. He also was treated with oral prednisolone (1 mg/kg) until his visual field showed significant improvement. The patient was discharged with public health precautions including aerosol droplet protection and directly observed therapy. Visual field testing 6 weeks later revealed resolution of the peripheral field loss and almost complete regression of right optic disc edema. 257 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Photo Essay FIG. 2. The right fundus demonstrates optic disc edema, whereas the left is normal in appearance. FIG. 3. Postcontrast coronal (A) and axial (B) MRI shows enhancement of the right optic nerve and its sheath. Optic perineuritis may be difficult to distinguish from optic neuritis (Table 1). Both are characterized by altered visual function and pain on eye movement. Patients with optic perineuritis may FIG. 4. Computed tomography of the chest reveals multiple areas of centrilobular nodules with a branching pattern suggestive of endobronchial tuberculosis. 258 present with preserved or near-normal visual acuity, as in our patient. The visual loss of optic perineuritis tends to be progressive over weeks compared with optic neuritis, which has a more acute course. Neuroimaging is essential in making the correct diagnosis. Contrast-enhanced MRI in optic perineuritis shows optic nerve enhancement and nerve sheath enhancement. The sheath enhancement external to the nerve appears on axial views as "tramtracks," whereas on coronal views, it may appear as a "doughnut" (2). In patients with optic perineuritis, treatment with systemic corticosteroid is essential to regain vision. By contrast, the final visual outcome in patients with demyelination associated optic neuritis is not altered with the use of corticosteroids (3). There is limited literature regarding the etiology of optic perineuritis. Although idiopathic inflammation is the most common cause (2), there are cases of optic perineuritis due to Behcet disease, sarcoidosis, Crohn disease, granulomatosis with polyangiitis, and syphilis (4-6). We are aware of only one other case report of optic perineuritis associated with tuberculosis. Ryu and Kim (7) described a 39-year-old Korean woman who reported abnormal vision in her right eye associated with pain on eye movement. Although acuity was 20/20 bilaterally, there was a right RAPD, a superior visual field deficit and right optic disc edema. MRI demonstrated enhancement of the posterior sclera Yates et al: J Neuro-Ophthalmol 2019; 39: 257-259 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Photo Essay TABLE 1. Features distinguishing optic perineuritis from optic neuritis Feature Visual loss Time course Etiology Optic Perineuritis Optic Neuritis Often paracentral, arcuate, or peripheral Subacute presentation over weeks to months Idiopathic orbital inflammatory disease Systemic lupus erythematosus Granulomatous disease including sarcoidosis, tuberculosis, and Crohn disease Neuroimaging Perineural enhancement including "tramtracks" on axial view or "doughnut sign" on coronal scan Treatment Dramatic response to corticosteroids; may relapse once steroids discontinued Usually central Sudden presentation, often days Demyelination-typical Autoimmune-neuromyelitis optica, chronic relapsing inflammatory optic neuritis Parainfectious-viral infection, immunization Infectious-bartonella, syphilis, cryptococcal meningitis, and herpes zoster Noninfectious-systemic lupus erythematosus, polyarteritis nodosa Optic nerve may appear normal or abnormal. Features include focal hyperintensity on T2 sequences and/or contrast enhancement on fatsuppressed T1 sequences With long-term follow-up, corticosteroids of no proven efficacy Adapted from (2). and optic nerve sheath of the right eye. Chest radiographs and laboratory studies were consistent with Mycobacterium tuberculosis, and treatment with antitubercular medications and methylprednisolone led to full recovery of vision. Our case represents an atypical presentation of tuberculosis in a patient who has lived in a high resource country for a number of years with no recent travel to an area endemic for tuberculosis. It also highlights the variety of potential causes of optic perineuritis. STATEMENT OF AUTHORSHIP Category 1: a. conception and design: W. B. Yates and M. Lawlor; b. acquisition of data: S. Nothing and W. B. Yates; c. analysis and interpretation of data: M. Lawlor and W. B. Yates. Category 2: a. drafting the manuscript: W. B. Yates, M. Lawlor, and S. Nothing; b. revising it for intellectual content: M. Lawlor. Category 3: a. final approval of the completed manuscript: all authors. Yates et al: J Neuro-Ophthalmol 2019; 39: 257-259 REFERENCES 1. Rossi SE, Franquet T, Volpacchio M, Gimenez A, Aguilar G. Tree-in-bud pattern at thin-section CT of the lungs: radiologicpathologic overview. Radiographics. 2005;25:789-801. 2. Purvin V, Kawasaki A, Jacobson D. Optic perineuritis: clinical and radiographic features. Arch Ophthalmol. 2001;119:1299-1306. 3. Optic Neuritis Study Group. Visual function 15 years after optic neuritisOphthalmology. 2008;115:1079-1082. 4. Lai C, Sun Y, Wang J, Purvin VA, He Y, Yang Q, Jing Y, Yin H, Zhu J. Optic perineuritis in Behcet disease. J Neuroophthalmol. 2015;35:342-347. 5. O'Connell K, Marnane M, McGuigan C. Bilateral ocular perineuritis as the presenting feature of acute syphilis infection. J Neurol. 2012;259:191-192. 6. McClelland C, Zaveri M, Walsh R, Fleisher J, Galetta S. 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