Preparation of corneal donor eyes comparing 1% versus 5% povidone-iodine

To compare the effect of 1% versus 5% polyvinylpyrrolidone-iodine (PVP-I) chemical preparation (prep) of the eye on the recovery of organisms from donor globes before in situ recovery of donor corneal tissue.

One hundred consecutive pairs of donor corneas (200 eyes) were randomized to receive either 1% or 5% PVP-I drops applied to the conjunctival cul-de-sac, which was left in place for 2 minutes. Limbal cultures were obtained before and after prepping of the eye.

Twenty-five different species of organisms were recovered. Native flora of the eye included coagulase-negative staphylococci (62%), Corynebacterium species (27%), streptococcal species (9.5%), gram-negative bacilli (14.5%), Staphylococcus aureus (5%), anaerobes (10%), and yeast (2%). After PVP-I instillation of the donor eye, 74 isolates were recovered from the 1% P-I group and 76 isolates from the 5% PVP-I group. Cultures were sterile after PVP-I prep in 49 eyes and 47 eyes in the 1% PVP-I group and 5% PVP-I group, respectively. Microorganism colony forming units were similar among post-prep cultures from both PVP-I groups. The effect of the PVP-I prep on the number of negative cultures and on the reduction in the number of isolates was highly significant for both the 1% PVP-I group and the 5% PVP-I group when compared with the limbal cultures taken before PVP-I instillation.

This study found that 1% and 5% PVP-I solutions are equally effective for chemical prep of the donor eye. Because PVP-I is known to be toxic to the corneal endothelium and corneal fibroblasts, this study suggests that 1% PVP-I should be the preferred disinfectant for the recovery of corneal donors.