An additional povidone-iodine (PVP-I) soak time of 5 minutes did not significantly alter the quality of corneal donor tissues, according to findings published in Cornea. In fact, the preparation method may reduce positive rim cultures, and postoperative infections, researchers report.
Bilateral ocular donors (n=5) that were deemed unsuitable for reasons not related to corneal tissues were included in this analysis. Bilateral cornea procurements occurred onsite within 15 hours of death by 2 experienced eye bank technicians. Both corneas underwent a 5-minute PVP-I rinse and soak. The right corneas underwent an additional 5-minute rinse and soak. The researchers compared tissue quality between single and double soak tissues. Outcomes from transplanted tissues were compared between corneas obtained during the single-soak policy time period in 2018 and 2019 (n=12,638) with tissues obtained after the double-soak policy change in 2019 and 2020 (n=10,927).
For all corneal regions, the proportion of dead epithelial cells ranged between 40% and 50%. No significant differences in cell densities were observed in central (P =.704), peripheral (P =.650) and limbus (P =.518) regions on the basis of single or double PVP-I exposure.
The proportion of corneas without epithelial defects was higher after the double soak policy change (73% vs 67%; P <.001) compared with single-soaked tissues, respectively. The double-soaked tissues, however, were associated with larger defect areas (mean, 21.62%) than the single-soaked tissues (mean, 18.87%; P <.001).
The corneas obtained during the single-soak protocol period had higher rates of no stromal edema (17% vs 8%; P <.001), fewer cases of mild edema (68% vs 78%; P <.001), and similar rates of moderate (15% vs 13%; P =.137) or severe (0.5% vs 0.4%; P =.299) edema, respectively.
The single-soak corneas had thinner central corneal thicknesses (mean, 526 vs 529 μm; P <.001) and greater endothelial cell densities (mean, 2617 vs 2593 cells/mm2; P =.009) compared with double-soak tissues, respectively.
The overall fungal and bacterial positive culture rates were 1.17% for the single-soak and 0.88% for the double-soak (P =.075) tissues.
“There was a significant concern from the eye bank medical advisory committee that implementation of double PVP-I exposure during tissue recovery could lead to epithelial toxicity,” according to the study authors. “Second PVP-I exposure does not result in additional epithelial toxicity. We hope that reduced numbers of postoperative infectious adverse reactions to our eye banks further strengthen the importance of the cost-effective use of the double PVP-I soak protocol to reduce donor tissue bioburden.”
This study may have been limited by the seasonal variation in positive rim culture rates.
Sawant OB, How S, Hurlbert S, et al. Effect of increasing povidone-iodine exposure on corneal epithelium and impact on donor rim cultures. Cornea. Published online August 25, 2022. doi:10.1097/ICO.0000000000003057