NEWS & EVENTS
Retinal Review, Issue 79
Authored by Danielle Strauss, MD
A 58 year-old woman was sent to OMNI for the evaluation of possible “papilledema.” She had a past medical history of hypertension, hyperlipidemia, and hypothyroidism. Her active medications included levothyroxine, simvastatin, and Lisinopril. On presentation, her Va cc was 20/20 OD and 20/25 OS, however she had an APD in the left eye. Anterior segment examination was unremarkable, except early NS changes in her lenses. The following are wide-field color fundus photos of her retinas.
Here is a magnified view of her optic nerves:
Examination of the optic nerves revealed a sharp pink nerve in the right eye with a 0.15 cup. In the left eye, however, there was segmental hyperemia of the optic nerve head with evidence of peripapillary splinter hemorrhages. Given the clinical examination, it was clear the patient did not have papilledema. By definition, papilledema is bilateral optic disc swelling due to increased intracranial pressure. In this case, the swelling was unilateral. It was associated with splinter hemorrhages and the patient had good visual acuity. Upon further questioning, the patient denied visual loss, peripheral scotoma or headaches. This finding had been found incidentally. She also denied pain while chewing, scalp sensitivity or muscle pain.
A Humphrey Visual Field test was performed in the office and showed the following:
The HVF 24-2 in the left eye showed superior altitudinal field loss.
Given the findings, the clinical picture was consistent with non-arteritic ischemic optic neuropathy (NAION). NAION commonly presents as unilateral painless vision loss. Anterior ischemic optic neuropathy can either be arteritic or non-arteritic, and by definition is an ischemic event to the anterior 1mm of the optic nerve head. 95% of patients with NAION are Caucasian. Risk factors include “disc at risk” (ie crowded disc or small cup to disc ratio), optic disc drusen, sleep apnea, nocturnal hypotension, or use of sildenafil. Generally, patients do not have accompanying pain or headache. Presenting visual acuity can range widely. Based on data from the IONDT trial, 49% of patients will present with vision better than 20/64. And 66% of patients will have vision better than 20/200. Patients may have an APD, and may have color vision loss. HVF will show a field defect that relates to the extent of the optic nerve damage.
In the acute phase of NAION, optic nerve edema will be present and will be accompanied by peripapillary splinter hemorrhages 2/3 of the time. The edema may be diffuse or segmental. There is no evidence-based- proven effective medical or surgical treatment for NAION. The use of aspirin or other anti-platelet agents was not shown to be effective in one study. If the patient has a history of hypertension, they should be advised not to take the medication before bed, to avoid nocturnal hypotension.
The visual prognosis with NAION is generally good with 50% of patient regaining vision of 20/30 or better. Over the course of 8 weeks, the optic nerve swelling resolves, and visual improvement occurs over the course of 3-6 months.
In this case, the patient’s vision remained 20/20, however, on serial HVF her scotoma persists. On 6 month follow up she has optic nerve head pallor. See photo below.