Purpose. Develop and test an ocular drug transfer system (OCCI) based on Coulomb's laws to obtain reliable intraocular drug concentration in a short time while avoiding tissue damage. Methods. A programmable 3 microcomputer chips electronic system was designed to produce an equipotential electrical field with a continuously monitored adjustable constant direct current source connected to 2 electrodes. The active ocular electrode has a constant liquid surface and a drug reservoir connected to 2 syringes containing the drug solution and a partial vacuum. A very low impedance return electrode is used. Transcorneal, transscleral and transcorneoscleral OCCIs were made for experimentation in rabbits and rats. The drug solutions were modified for optimal iontophoretic transfer. Results. No extra- or intraocular tissues damage was detected clinically or by light microscopy. A ≥0.08C/cm2 transcorneal transfer of pimaricin produced 3 MMC in 4min. A ≥500μg/ml Di-hematoporphyrinether intracorneal concentration was obtained for PDT treatment of acanthamoeba infections. Higher intravitreal concentration of fluorescein and dexamethasone were obtained. Conclusion. This pilot study demonstrates OCCI's safety and effectiveness with 4 drugs. Ganciclovir and other drugs are under study. Pharmacokinetics and TEM analyses and extended in vivo studies are necessary before using OCCI in clinical trials.
|Journal||Investigative Ophthalmology and Visual Science|
|State||Published - Feb 15 1996|
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