BACKGROUND: Non-arteritic ischemic optic neuropathy (NAION) is a result of small vessel disease that leads to a sudden decrease in the arteriolar pressure-perfusion ratio. In the eye, the vessels involved are the short-posterior ciliary arteries. When the perfusion of these arteries is decreased, neuronal cell death occurs, which results in profound vision loss. The onset of vision loss is commonly unilateral with NAION, but in extremely rare cases concurrent bilateral vision loss can occur.
CASE REPORT(S). A 56 year old white male presented to the emergency room with a sudden onset of painless central vision loss OD. Visual acuities were 20/60- PHNI OD and 20/20 OS. Humphrey visual fields (30-2 sita fast) showed superior altitudinal defects in both eyes with OD>OS. Dilated fundus exam revealed small and crowded optic discs with inferior edema and pallor OU. A thorough review of the patient's medical history showed a recent history of hypotension, which was likely due to multiple hypertensive medications used to treat his peripheral cellulitis. His blood pressure on the date of the examination was 83/66. The patient was diagnosed with bilateral non-arteritic ischemic optic neuropathy secondary to medically induced systemic hypotension.
CONCLUSIONS. Non-arteritic ischemic optic neuropathy is a condition in which the short posterior ciliary arteries prevent adequate perfusion of blood to the optic nerve. Simultaneous bilateral onset is extremely rare and typically occurs with serious systemic vascular disease or acute hypotensive events, including hemorrhage, shock, and surgery.