By Lauren Patty, MD
Contributing Editor
A 51 year old Caucasian male trumpet player with obstructive sleep apnea on CPAP presented to Doheny Eye Institute complaining of painless darkening of vision OS > OD for 2 mos, with rapid onset. During creation of a right forearm AV fistula for hemodialysis 4 mos prior to his visit, he began having a large amount of edema of his right hand, both arms, neck, and face. He was told by an outside ophthalmologist that his decreased vision was secondary to macular edema from fluid buildup, and when the fistula was tied off his vision improved OD > OS but remained decreased in both eyes. His exam was significant for decreased vision, brightness sense, and color plates in both eyes and a positive rAPD in the left eye. Dilated fundus exam showed diffuse optic nerve pallor OU with 3+ atrophy OD and 4+ atrophy OS. A superior altitudinal defect on Humphrey visual field was evident in the right eye and generalized depression with increased density of superior losses in the left. Given the patient’s history and clinical findings, a diagnosis of ischemic optic neuropathy was made in both eyes, posterior in the left eye but likely more anterior in the right.
Ischemic optic neuropathy results from a critical loss of blood flow to the retinal ganglion cell axons and surrounding glial tissue and can be divided into anterior and posterior types. A review of the blood supply of the optic nerve is critical to the understanding of this disease process, and a brief discussion of clinical findings and management follows. As this patient had the additional interesting risk factors of being on chronic hemodialysis, having obstructive sleep apnea, and playing a high resistance wind instrument, the pathogenesis of ischemic optic neuropathy in this particular case is examined along with a review of pertinent literature.