From the Guidelines
Thiamine deficiency can cause severe ocular manifestations, including optic neuropathy, which is a critical component of Wernicke-Korsakoff encephalopathy, as noted in the espen micronutrient guideline 1. The eye findings associated with thiamine deficiency are primarily related to the neurological symptoms of the condition, which can range from mental changes and cognitive deficits to more severe conditions like Wernicke-Korsakoff encephalopathy. Key ocular manifestations include:
- Nystagmus
- Ophthalmoplegia, especially lateral rectus palsy
- Conjugate gaze palsies
- Optic neuropathy with decreased visual acuity
- Pupillary abnormalities
- Retinal hemorrhages
- Papilledema in severe cases
These ocular manifestations are critical components of Wernicke's encephalopathy, characterized by the triad of ocular abnormalities, ataxia, and confusion. The treatment of thiamine deficiency, particularly in the context of Wernicke's encephalopathy, requires immediate administration of thiamine. According to the espen micronutrient guideline 1, the recommended dose for high suspicion or proven deficiency, including Wernicke encephalopathy, is 500 mg IV three times a day.
The immediate initiation of thiamine therapy is crucial, as thiamine reserves can be depleted as early as 20 days of inadequate oral intake, and early treatment can prevent long-term neurological damage, including ocular manifestations 1. In cases of suspected thiamine deficiency, especially with risk factors such as prolonged vomiting, rapid weight loss, or alcohol abuse, immediate oral or intravenous thiamine treatment should be initiated without delay, pending test results, as emphasized in the british obesity and metabolic surgery society guidelines 1.
Given the potential for severe consequences from untreated or late-treated thiamine deficiency, education on the risks and importance of early treatment is essential for both patients and clinicians, as highlighted in the guidelines 1 and 1. The maintenance dose after initial treatment can be adjusted based on the clinical response and the presence of any underlying conditions that may affect thiamine metabolism or absorption.
From the Research
Eye Findings with Thiamine Deficiency
- Ophthalmoparesis, horizontal nystagmus, and decreased gain of the horizontal vestibulo-ocular reflex (VOR) are common eye findings in thiamine deficiency 2
- Bilateral symmetric vestibular loss has also been observed in patients with thiamine deficiency 2
- Thiamine deficiency can cause optic neuropathy, leading to visual complaints 3
- Ocular motor abnormalities, such as oculomotor disturbances, can occur in thiamine deficiency 4, 2
- These eye findings can be present in the early pre-encephalopathy stage of thiamine deficiency and may respond to timely treatment with parenteral thiamine 2
Diagnosis and Treatment
- Diagnosis of thiamine deficiency is primarily clinical, with complementary tests used to support the diagnosis and rule out other causes of similar symptoms 5
- Treatment with parenteral thiamine should be started early in patients with compatible symptoms, without waiting to confirm the diagnosis 5
- The optimal dose of thiamine for treatment and prevention of Wernicke-Korsakoff syndrome is not well established, but high doses may not be necessary 4
Clinical Presentation
- Thiamine deficiency can present with a range of symptoms, including loss of appetite, dizziness, tachycardia, and urinary bladder retention 3
- Confusion or delirium is part of the classic triad of Wernicke encephalopathy, a condition caused by thiamine deficiency 3
- Severe concomitant infections, including sepsis of unknown origin, can occur in patients with thiamine deficiency 3