A 26-year-old woman comes to the office due to blurry vision in her left eye. She first noticed a "smudge" in the center of her left vision 2 days ago. The patient had been using the computer more than normal to study for an examination and thought that this might be the cause. She ceased using the computer, but the smudge gradually enlarged to involve almost the entire left visual field. She also reports that colors appear "washed out." The patient has mild left ocular discomfort with eye movement. She has no chronic medical problems. Temperature is 36.7 C (98 F), blood pressure is 124/82 mm Hg, and pulse is 78/min. Visual acuity is 20/200 in the left eye and 20/20 in the right. When light is moved from the right eye to the left, the left pupil dilates. Muscle strength, deep tendon reflexes, and sensation are normal. Funduscopic examination is unremarkable. Which of the following is the most likely diagnosis?
Optic neuritis | |
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This patient likely has optic neuritis, an inflammatory demyelination of the optic nerve. Optic neuritis is thought to be immune-mediated and is most commonly seen in women age 20-40. Symptoms develop acutely and usually include monocular vision loss, pain with eye movement, and "washed-out" color vision. Examination typically reveals an afferent pupillary defect (paradoxical pupillary dilation of the affected eye with the swinging-flashlight test) and central scotoma. Funduscopy is usually normal as inflammation occurs behind the optic nerve head.
Optic neuritis is strongly associated with multiple sclerosis and is frequently the heralding symptom of this condition. As such, patients are typically evaluated with MRI of the orbits and the brain to look for other areas of inflammation.
(Choice A) Acute anterior uveitis is usually painful and causes a red eye, blurry vision, and photophobia. Central scotoma, afferent pupillary defect, and color vision abnormalities would be atypical.
(Choice B) Central retinal artery occlusion primarily affects elderly patients and causes acute, severe, and painless monocular vision loss. Funduscopy abnormalities (eg, retinal whitening, cherry red spot) are almost always present.
(Choice C) Cortical blindness is the result of damage to the cerebral visual pathways and usually causes total or partial vision loss with normal pupil and funduscopic findings.
(Choice D) Macular degeneration is a painless, progressive loss of central vision that typically occurs in older patients, especially those with vascular risk factors. Both eyes are often affected, and funduscopic abnormalities (eg, drusen [yellow deposits]) are prominent.
(Choice E) Open-angle glaucoma is usually characterized by gradual painless peripheral vision loss. Funduscopy typically demonstrates optic disc enlargement with an increased cup:disc ratio.
(Choice G) Patients with retinal detachment usually see floaters or flashes of light and lose peripheral vision first.
Educational objective:
Optic neuritis is usually characterized by the acute onset of monocular vision loss with central scotoma, afferent pupillary defect, changes in color perception, and pain with eye movement. There is a strong association between optic neuritis and multiple sclerosis.