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2017 Agenda and Abstracts | < Previous Next >


2017 OMIG Abstract 13

Intravitreal Monotherapy with Triamcinolone-Moxifloxacin is Less Effective Than Triamcinolone-Moxifloxacin-Vancomycin for Preventing Endophthalmitis in a Rabbit Model
Regis P. Kowalski, Eric G. Romanowski, Robert M.Q. Shanks, Alex Mammen, Deepinder K. Dhaliwal
The Charles T. Campbell Ophthalmic Microbiology Laboratory, University of Pittsburgh Medical Center (UPMC), University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania


Purpose: The use of intravitreal injections of antibiotics and anti-inflammatories has gained interest for surgical prophylaxis. We tested intravitreal triamcinolone-moxifloxacin-vancomycin (TMV) and triamcinolone-moxifloxacin (TM) for preventing Staphylococcus aureus (SA) endophthalmitis in rabbits.

Methods: Formulations of TMV (15/1/10 mg/ml) and TM (15/1 mg/ml) were provided by a trademark compounding pharmacy. Seven groups of 8 rabbits each (A-G) were tested with intravitreal injections of medication or control. Prior to intravitreal injection, the vitreous was first challenged with clinical SA endophthalmitis isolates (5000 CFU) with varying minimum inhibitory concentrations (MIC in µg/ml) to moxifloxacin (denoted by the MIC at the end of each group listed): A) TMV-10, B) TM-10, C) Saline-10, D) TM-2, E) Saline-2, F) TM-0.032, and G) Saline-0.032.  After 24 hours, the rabbit eyes were graded for clinical endophthalmitis, and cultured for viable SA.

Results: Rabbits treated with TMV and challenged by SA with a moxifloxacin MIC of 10 μg/ml did not present with endophthalmitis (0/8, no eyes with endophthalmitis). For SA with moxifloxacin MICs of 10.0 and 2.0 μg/ml, TM did not prevent endophthalmitis (16/16, 100% of eyes with endophthalmitis). For SA with a moxifloxacin MIC of 0.032 μg/ml, endophthalmitis was prevented with TM (0/8, no eyes with endophthalmitis). All saline treated eyes developed endophthalmitis (23/23, 100% of eyes with endophthalmitis).

Conclusions: Intravitreal TMV prevented endophthalmitis by SA with an elevated MIC to moxifloxacin, whereas TM did not provide consistent prevention of SA endophthalmitis. Vancomycin appears to be essential for intravitreal prophylaxis and monotherapy with moxifloxacin is less effective.

Disclosure: S – Trademark Compounding pharmacy from San Diego, CA


2017 Agenda and Abstracts | < Previous Next >