A 54-year-old woman was referred for evaluation of decreased vision. She reports blurry vision in the left eye for one month. Specifically, she says there are gray blotches moving in the superior part of her visual field, and her vision comes and goes when the blotch moves down into the center of vision.
Besides low myopia, her past ocular history is unremarkable as is her medical history. On exam, her BSCVA is 20/20 OD and variable, ranging from 20/20 to 20/70 OS. Pupillary exam, extraocular motility, confrontation visual fields, and IOP are all normal. Anterior segment exam is normal. Examination of the posterior pole shows the following optic nerve appearance:
What abnormal finding is shown in the image above?
Optic nerve head edema OS with blurred disc margins 360 degrees, loss of the optic cup, and an intraretinal flame hemorrhage at the inferior edge of the disc.
What is the differential diagnosis?
The DDx includes anterior ischemic optic neuropathy (AION), optic neuritis, papillitis, neuroretinitis, and other forms of optic neuropathy (compressive, traumatic, infiltrative/infectious).
What additional history would you obtain to narrow the diagnosis?
It is important to ask about symptoms of giant cell arteritis (i.e., headache, temporal area pain, scalp tenderness, jaw claudication, fever and weight loss) and other neurologic symptoms. Although the patient denies any significant past medical history, she should be questioned specifically about risk factors for nonarteritic AION (i.e., vasculopathic disorders such as hypertension and diabetes, hypercholesterolemia, smoking) as well as any history of head or eye trauma, or any history of cancer, autoimmune, infectious, or thyroid disease?
Additional information: Upon further questioning, the patient has not experienced any symptoms of GCA and a neurologic review of symptoms is negative. She has no history of systemic disease and takes no medication. She recently had an annual physical exam with her internist and her blood pressure and blood glucose levels are normal.
How would you treat this patient?
Despite the lack of history and slightly young age of the patient for arteritic AION, GCA must still be ruled out with stat lab tests (ESR and CRP). Because blood is being drawn, additional tests to order include CBC with differential, fasting blood glucose, ANA, and VDRL/FTA-ABS.
Additional information: The patient’s blood work was negative. The ESR was 8 and the CRP was normal.
What would you do next?
The next management step is to obtain neuroimaging and visual field tests.
Additional information: The patient underwent an MRI of the brain and orbits with gadolinium and fat suppression, which was normal. Visual field testing demonstrated a central scotoma OS.
What is the diagnosis?
The patient has presumed nonarteritic AION.
What is the treatment?
NAION has no treatment. The patient was referred to a neurophthalmologist and has since developed a relative afferent pupillary defect and optic disc pallor OS.
Discussion: This case demonstrates an atypical presentation of NAION and the importance of a careful history and exam. The suspicion of AION requires prompt management to determine whether it is arteritic so that treatment with steroids can be initiated to prevent visual loss in the fellow eye. If GCA is presumed despite normal lab results, then temporal artery biopsy is usually performed, but treatment with steroids should not be delayed.