Elevated IOP following a bladder filling protocol: A case report

We describe a patient with elevated intraocular pressure (IOP) secondary to an oral water bolus and examine the utility of the water-drinking test. A 66-year-old male with a history of hypertension presented with headache, bilateral retro-orbital ache, and blurry vision. Symptoms began shortly after his radiation treatment for prostate cancer, for which he consumed a water bolus to fill his bladder 30 minutes prior to treatment initiation. On exam, he had bilateral elevated IOP that responded to topical IOP-lowering medications. Gonioscopy demonstrated open angles and fundus exam showed non-glaucomatous optic nerves with pronounced retinal venous tortuosity. The water-drinking test showed a peak intraocular pressure of 20 mmHg in the right eye (5 mmHg increase from baseline) and 23 mmHg in the left eye (8 mmHg increase from baseline), suggesting impairment of the outflow system in the left compared to the right eye. He was started on topical IOP-lowering therapy and followed in our clinic as a glaucoma suspect. Consumption of a water bolus can be associated with IOP elevation and may be a risk factor in patients with otherwise normal IOPs at risk for glaucoma. The water-drinking test was historically used as provocative testing for open-angle glaucoma and may have an updated role in evaluating at-risk patients without ocular hypertension.