Comparison of Povidone-Iodine and Gentamicin Soak as Scleral Buckle Infection Prophylaxis

To determine the best method of antimicrobial prophylaxis against implanted material-associated infections in the setting of scleral buckle surgery.

Experimental study.

Scleral buckle elements were soaked in either gram-positive or polymicrobial broth, while control buckle elements were soaked in PBS only.

Solid silicone and sponge scleral buckle elements were inoculated with common pathogens of the ocular surface, and then soaked in either 1% or 5% povidone-iodine, 1 mg/mL gentamicin solution, or sterile saline for 1, 5, 10, or 15 minutes. Bacteria were then isolated from the buckle elements and cultured for 24 hours.

In all gram-positive bacterial conditions, gentamicin solution decreased the bacterial load from 451,666.67 colony-forming units (CFU)/mL to 171,611.11 CFU/mL (p=0.0004). The fractional bacterial survival after soaking in gentamicin was higher for the silicone sponge than band (0.357 vs 0.079, p=0.038). Both 1% and 5% povidone-iodine were able to completely eradicate all gram-positive bacteria of both buckle elements. Only 5% povidone-iodine was able to completely sterilize all microbes on the buckle after soaking in a polymicrobial solution consisting of gram-positive, gram-negative bacteria, and fungi.

Povidone-iodine solution was significantly more effective at bacterial eradication compared to gentamicin solution. For all scleral buckle procedures, we recommend soaking the buckle element in 2-3% povidone-iodine solution before placement and rinsing the ocular surface with the same solution after placement.