Case Report: Nutritional and Toxic Optic Neuropathy: A Diagnostic Dilemma

Abstract

SIGNIFICANCE Nutritional and toxic optic neuropathies are rare disorders characterized by visual impairment due to optic nerve damage by a toxin, usually with coexisting nutritional deficiencies. Its pathophysiology is still unclear, and multiple mechanisms implicated act synergistically to bring about this condition. The decline in its incidence and its confusing clinical appearance make diagnosing nutritional and toxic optic neuropathies challenging. PURPOSE This is an observational clinical case report of an atypical clinical case of a nutritional and toxic optic neuropathy with a subacute presentation and papilledema at the time of diagnosis. The patient provided written informed consent for medical information and images to be published. CASE REPORT A 47-year-old man presented with progressive, painless bilateral decrease in central vision over 15 days. The patient had a long-standing history of alcohol abuse and was a heavy smoker. The examination revealed dyschromatopsia, 20/400 visual acuity on both eyes, and no relative afferent pupillary defect. Funduscopy revealed bilateral papilledema. A visual field test showed generalized depression with centrocecal involvement in the left eye. Laboratory studies evidenced decreased vitamin B12/B1 and red blood cell folate levels, increased acute phase reactants, hypertransaminasemia, and macrocytic anemia. Serologies and methanol in urine were negative. After the discontinuation of tobacco use and alcohol accompanied by vitamin supplementation, our patient's visual field, visual acuity, and papilledema improved remarkably. After 5 months, visual acuity and funduscopy were normal. CONCLUSIONS Although some hallmark signs were visible in this case, its subacute presentation and the presence of papilledema at diagnosis caused some diagnostic uncertainty. Nutritional and toxic optic neuropathy is a rare and challenging diagnosis because of a lack of biomarkers. Eye care clinicians should consider nutritional and toxic optic neuropathies to prevent severe and irreversible visual damage resulting from underdiagnosis and mismanagement.

Micronutrient Deficiencies Presenting with Optic Disc Swelling Associated with or without Intracranial Hypertension: A Systematic Review

“…We identified 11 cases of vitamin B12 deficiency presenting with optic disc swelling, which were all caused by poor intake and none from malabsorption ( Table 3 and Table S7 ) [ 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 ]. Due to the exclusion criteria of this review, none of these cases were severely anaemic (defined as haemoglobin ≤8.0 g/dL) [ 13 ].…”

Visual electrophysiology in the assessment of toxicity and deficiency states affecting the visual system

“…Although the onset of toxic-nutritional optic neuropathy is usually insidious with few fundoscopic signs, transient optic disc swelling and telangiectases, and peripapillary haemorrhages sometimes occur [ 83 ], prompting comparisons with methanol and ethambutol optic neuropathy and Leber hereditary optic neuropathy (LHON).…”

Neuropatia óptica carencial - relato de caso

“…As alterações de disco óptico incluem edema leve, hiperemia moderada, hemorragia, com palidez de disco temporal e afinamento da camada de fibras nervosas do feixe papilomacular e, tardiamente, atrofia óptica 4 . O reflexo pupilar fotomotor pode estar levemente reduzido 5 . Este padrão assemelha-se a neuropatia hereditária de Leber e à óptica tóxica 6 .…”