Water drinking and outflow facility.

In a series of patients with ocular hypertension, the effect of water drinking upon pressure and outflow facility was determined by impression (Schiotz) tonometry and tonography. The statistical facility-depressing effect of water drinking revealed by numerous earlier studies was confirmed, but found to be too small to be readily demonstrable in the individual eye. The water-drinking test in patients with primary ocular hypertension presents a situation in which tonography adds little to the information provided by tonometry.