PREVIOUS OCULAR COMPRESSION INCREASES INTRAOCULAR PENETRATION OF SYSTEMIC DRUGS

Intraocular drug penetration is dependent upon the physical and chemic al characteristics of the drug, the manner of drug administration and the drug's ability to pass through the blood/aqueous barrier. Most sys temically administered drugs do not achieve intraocular therapeutic le vels. The authors present a new method to increase the intraocular con centration of intravenously administered drugs based on the premise th at ocular hypotony by ocular compression produces a temporary break in the blood/aqueous barrier during the period of hypersecretion that fo llows to regain normal intraocular pressure levels. Vancomycin introdu ced parenterally was used as the drug model. The right eye of 22 rabbi ts served as experimental eye, while the left eye served as control. T he concentrations of vancomycin in the aqueous humor half an hour afte r intravenous injection of 40 mg/kg vancomycin in 50 ml of lactated Ri nger's solution were as follows: 30.17 +/- 20.68 mu g/ml in the right (hypotonized) eyes and 4.92 +/- 3.33 mu g/ml in the left (control) eye s. The difference in drug levels between the two sets of eyes had a hi gh statistical significance at p = 0.001.