The Distribution of 5,5-Dimethyl-2, 4-Oxazolidinedione (DMO)

II. Studies of the Effect of Carbonic Anhydrase Inhibitors and of Plasma Levels

¹ Department of Ophthalmology and the Oscar Johnson Institute, Washington University School of Medicine, St. Louis, Mo

The effect of plasma level of 5, 5-dimethyl-2, 4-oxazolidinedione (DMO) and of inhibitors of aqueous secretion on the distribution of DMO in intraocular fluids has been studied. Plasma levels of DMO from 35 to 60mg./100 ml. were required to obtain an appreciable excess of DMO in posterior and anterior aqueous humors compared with plasma. At plasma levels below 20 mg./100 ml. the concentration of DMO in posterior aqueous humor generally was in deficit relative to plasma. After the administration of inhibitors of carbonic anhydrase, the level of DMO in the plasma decreased probably as a result of the increased alkalinity of urine and the plasma acidosis which these drugs cause. The concentration of DMO in the posterior and anterior aqueous humor frequently increased, but the change in concentration of DMO in these fluids was modified by the fall inplasma levels. The concentration of DMO in the vitreous humor increased relative to the plasma level and frequently in actual concentrations to levels often higher than that of the posterior aqueous humor or of plasma levels found before the administration of inhibitors. Factors which may influence the distribution of DMO in intraocular fluids are discussed.