Intracameral Antibiotic Safety Study

Use of injectable prophylactic intracameral antibiotics during cataract surgery is gaining popularity worldwide due to the growing body of scientific evidence supporting its use. To date, there is no sterile-packaged antibiotic that has FDA approval for this indication. Surgeons using intracameral injectable antibiotics during cataract surgery must use existing pharmaceuticals off-label and/or rely on imprecise and sub-sterile compounding pharmacies to dispense these types of medications. Both of these scenarios may pose significant risk to patient safety.

Description of the Treatment: Approximately 0.2 mL of either pre-loaded sterile vancomycin hydrochloride 1% solution (1 mg/0.1 mL of normal saline) or moxifloxacin hydrochloride 0.15% solution (150 μg/0.1 mL of normal saline) is injected into the eye with a blunt tip 30 gauge cannula through a small clear corneal incision as the last step in the cataract removal procedure. The purpose of the treatment is for prophylaxis against post-operative infections and endophthalmitis.

Description of Effector Pharmaceuticals/Drugs: Vancomycin is a hydrophilic glycopeptide antibiotic that has been well studied in many different forms: intravenous injectable, oral tablet and even topical eye drop solutions. It is derived from Actinobacteria spp. Moxifloxacin is a synthetic fourth generation fluoroquinolone and has, likewise, been available in many forms including intravenous injectable, oral tablet and topical eye drop solutions. In this study, a contracted compounding pharmacy will produce the two pharmaceutical agents at the concentration/dosage mentioned above under the USP 797 guidelines.

Therapeutic Mode of Action: The primary mode of action for vancomycin is inhibition of cell wall synthesis in gram positive bacteria. The molecule forms hydrogen bonds with terminal amnio acid moieties of the N-acetylmuramic acid (NAM) and N-acetylglucosamine (NAG) polymer. The disruption to the polymerization and cross-linking of NAM-NAG complexes undermines the structural integrity of the bacterial organism leading to bacteriostasis and eventually cell death. The primary mode of action for moxifloxacin is inhibiting DNA gyrases, both type II topoisomerase and topoisomerase IV. These enzymes are essential for bacterial DNA replication to occur.