A 74-year-old woman is brought to the emergency department for evaluation of sudden vision loss in her left eye that began 2 hours ago. For the past 3 weeks, she has experienced persistent left-sided headaches and pain in her jaw while chewing her food. She also reports generalized malaise and aching in her shoulders and hips that is worse in the morning. On physical examination, her visual acuity is 20/20 in the right eye and light perception only in the left eye. There is a prominent, tender, non-pulsatile cord-like structure on her left temple. Funduscopic examination of the left eye reveals a chalky-white, swollen optic disc. Laboratory studies show an erythrocyte sedimentation rate (ESR) of 105 mm/h and a C-reactive protein (CRP) of 12 mg/L (N: <3.0).
Which of the following is the most appropriate next step in the management of this patient?
The correct answer is:
A) High-dose intravenous methylprednisolone
This patient is presenting with arteritic anterior ischemic Optic neuropathy (AAION) caused by giant cell arteritis (GCA), also known as temporal arteritis. This is a medical emergency. The clinical picture is classic with an elderly patient with new-onset headache, jaw claudication, and symptoms of polymyalgia rheumatica, including aching in the shoulders and hips. The vision loss in GCA is often profound and can become bilateral if not treated immediately. The funduscopic finding of a "chalky-white" swollen optic disc is highly suggestive of AAION. When a patient presents with vision loss and high clinical suspicion for GCA, the most appropriate next step is high-dose intravenous methylprednisolone to protect the remaining vision and prevent involvement of the contralateral eye.
Answer choice B: Low-dose oral prednisone, is incorrect. While oral prednisone is the treatment for isolated polymyalgia rheumatica, it is insufficient for GCA with ocular involvement. Patients with visual symptoms require immediate IV steroids followed by high-dose oral steroids.
Answer choice C: MRI of the brain and orbits, is incorrect. While an MRI might show enhancement of the optic nerve or scalp ischemia, GCA is a clinical and laboratory diagnosis. Imaging would only delay the initiation of sight-saving corticosteroids.
Answer choice D: Temporal artery biopsy, is incorrect. A temporal artery biopsy is the gold-standard test to confirm the diagnosis of GCA. However, it should never delay the initiation of corticosteroid therapy. The biopsy can still show characteristic giant cells and internal elastic lamina fragmentation even after several days of steroid treatment.
Answer choice E: Topical latanoprost, is incorrect. This is a prostaglandin analog used to treat open-angle glaucoma by increasing aqueous outflow. It has no role in the management of ischemic optic neuropathy or systemic vasculitis.
Key Learning Point
Giant cell arteritis (GCA) is a systemic vasculitis that can lead to permanent blindness via arteritic anterior ischemic optic neuropathy (AAION). In patients presenting with sudden vision loss, elevated inflammatory markers, and systemic symptoms such as headache and jaw claudication, immediate high-dose intravenous corticosteroids must be administered before waiting for the results of a temporal artery biopsy.
