Acute Bilateral Visual Loss Related to Orthostatic Hypotension
A 50-year-old man was referred to us due to decreased visual acuity in both eyes. The patient had spondylolisthesis and had undergone a lumbar laminectomy three months prior to these symptoms. After the operation, he had been bed-ridden in the supine position. The day before the visit, the patient had sat up for the first time and experienced momentary dizziness, nausea and facial pallor. Blood pressure decreased from 135 / 85 mmHg to 90 / 60 mmHg. A few hours later, the patient complained of blurred vision in both eyes. The next day, we measured a best-corrected visual acuity (BCVA) of 0.3 in both eyes. The pupillary light reflex was decreased in both eyes. Fundus examination revealed optic disc edema in both eyes and a peripapillary flame-shaped hemorrhage in the left eye (). The Humphrey visual field test demonstrated generally decreased sensitivity in both eyes. Fluorescein angiography showed definite delayed dye filling of both of the optic discs. Contrast-enhanced orbital magnetic resonance imaging did not show remarkable findings, and there was no retrobulbar pain. The patient had iron deficiency anemia, and his hemoglobin level was 10.5 g/dL. He also had benign prostate hypertrophy and was prescribed tamsulosin (0.2 mg daily). Systemic evaluations including laboratory and cardiovascular work-up showed no other abnormal findings. The cardiovascular work-up included echocardiogram and magnetic resonance angiography of the carotid arteries. Methylprednisolone pulse therapy was initiated. However, the next day, vision in the right eye further decreased to 0.05. Vision stabilized for the next 10 days. Two weeks after the initial visit, fluorescein angiography showed improved dye filling on both optic discs. However, improvement was not complete in the right optic disc (). Vision slowly improved and, after six months, BCVA was 0.4 and 0.6 in the right and left eyes, respectively. Both optic discs were pale, and retinal nerve fiber layer thinning was prominent (). The visual field remained severely constricted.