Acute Vision Loss as the Sole Presenting Symptom of Posterior Reversible Encephalopathy Syndrome.

A 45-year-old female with poorly controlled HTN presented with sudden, painless bilateral vision loss over 12 hours. On examination, she had only light perception in both eyes, with normal fundoscopy and no focal neurological deficits. Laboratory tests revealed mildly elevated creatinine and proteinuria. Imaging with MRI showed symmetrical hyperintensities in the occipital and parietal lobes, consistent with posterior reversible encephalopathy syndrome (PRES), while magnetic resonance angiography excluded large vessel occlusion. She was admitted to the intensive care unit, where blood pressure was controlled with intravenous labetalol, followed by oral antihypertensive therapy. Her vision improved within three days, and a repeat MRI on day five showed a resolution of the hyperintensities. The patient was discharged on day five with stable blood pressure and instructions for strict antihypertensive adherence. At a two-week follow-up, her visual acuity returned to baseline, and her serum creatinine normalized. This case emphasizes the importance of early diagnosis and management of PRES, particularly in patients with uncontrolled HTN, to prevent long-term neurological damage and recurrence.