Osmotic agents, chiefly urea and mannitol, currently are widely utilized to obtain rapid and profound, albeit transient, drops in the intraocular and intracranial pressure. Ideally such an agent should be effective both orally and intravenously, since the oral route in appropriate patients would avoid the hazards associated with the introduction of hypertonic solutions directly into the vascular system. Although Javid1 utilized urea (and effectively so) via the gastric route, the emetic and purgative effect made him consider the intravenous route preferable. Since mannitol is not absorbed from the intestinal tract, it is not effective when given by mouth.The present investigation concerns the effect of orally administered glycerin (glycerol) on the intraocular tension in 16 glaucomatous eyes.
Glycerin (Mallinckrodt, C. P.) in various amounts diluted with orange juice to a total volume of 250 cc was given orally to uncontrolled glaucoma patients selected from the Eye Clinic
THOMAS RP. GlycerinAn Orally Effective Osmotic Agent. Arch Ophthalmol. 1963;70(5):625-628. doi:10.1001/archopht.1963.00960050627008