From the Guidelines
When evaluating unilateral vision loss that returns, a thorough workup is essential to identify the underlying cause and prevent recurrence, starting with a detailed medical and ocular history, including specific questions about symptoms of diplopia, vision loss, and details on the nature and timing of the trauma, as recommended by the American Academy of Ophthalmology 1. The workup should include a comprehensive eye examination, with attention to vision testing, refraction, pupillary examination, IOP measurement, confrontational visual field testing, slit-lamp examination, and a dilated or undilated fundus examination, to rule out any globe injury or sight-threatening injury 1. Some key points to consider in the workup include:
- A detailed sensorimotor exam should be performed, with attention to versions, ductions, saccades, pursuit, vergence, and near reflex, along with alignment in multiple gaze positions with attention to primary and secondary deviations 1
- Imaging studies, such as carotid ultrasound and brain MRI with contrast, may be necessary to evaluate for structural lesions or stenosis, as suggested by the American College of Radiology 1
- Specialized tests, such as optical coherence tomography, fluorescein angiography, and visual field testing, may be considered to assess retinal structure, retinal circulation, and map any persistent defects
- The urgency of this workup is high, as transient vision loss may precede permanent vision loss or stroke, and common causes include amaurosis fugax from carotid emboli, migraine with aura, giant cell arteritis in older patients, retinal vascular occlusions, and optic neuritis, each requiring specific management approaches 1.
From the Research
Unilateral Vision Loss
- Unilateral vision loss can be caused by various conditions, including optic neuritis, ischemic optic neuropathy, and traumatic optic neuropathy 2
- Optic neuritis is a demyelinating condition that features color desaturation, relative afferent pupillary defect, and pain with extraocular muscle movements, and is often treated with high-dose steroids 3
Diagnostic Approach
- A thorough history and examination are essential in guiding further tests for unilateral vision loss 4
- Common and dangerous conditions causing sudden vision loss include acute angle-closure glaucoma, retinal detachment, retinal artery occlusion, giant cell arteritis, and optic neuritis 3
- Diagnostic tests such as visual field testing, optical coherence tomography, and magnetic resonance imaging may be necessary to determine the underlying cause of vision loss
Treatment
- The treatment of optic neuritis typically involves high-dose steroids, with the goal of speeding up visual recovery 2, 5
- However, the use of steroids in ischemic and traumatic optic neuropathies is highly controversial, and the evidence for their efficacy is limited 2
- In cases of giant cell arteritis, immediate initiation of empiric steroids is necessary to prevent vision loss in the unaffected eye 3