Abstract
Purpose :
The purpose of this study is to assess subsequent epithelial toxicity of a second povidone-iodine (PVI) application at the time of donor tissue recovery. Recent reports suggest that a second 5-minute application of PVI at the time of tissue recovery significantly reduces bioburden. Toxicity of the epithelium is of particular concern for those tissues utilized with longer recovery to surgery intervals as the damaged epithelium allows for increased corneal edema.
Methods :
Corneal excision was performed on four donors. The left eye of each donor was prepared using one 5-minute application of PVI followed by a rinse with sterile solution, while the right eye received one 5-minute application of PVI, a rinse with sterile solution, conjunctival removal, and a second 5-minute application of PVI followed by a final rinse. Death to preservation time for all donors was under 15 hours and tissues were processed for staining the morning following recovery. The corneas were stained with Calcein AM and Propidium Iodide (PI) for detection of live and dead cells, respectively. After staining, corneas were cut into halves. One half was put on the slide for flat mount imaging, the other half was dipped in OCT compound for cryosectioning. Corneal epithelial cell imaging was performed using Zeiss HAL100 fluorescent microscope. Imaging was performed at the central, limbal and scleral regions. Cell counting for live and dead cells was performed using corneal flat mounts at 10x.
Results :
The mean percentage cell death rate for the left (34 ± 5 %) and right (37 ± 7 %) eyes did not differ significantly. Total number of live (L: 833 ± 146 cells/mm2, R: 774 ± 120 cells/mm2) and dead (L: 494 ± 148 cells/mm2, R: 551 ± 204 cells/mm2) cells were unaltered between left and right eyes.
Conclusions :
These results indicate that an additional PVI application at the time of tissue recovery does not increase epithelial death beyond what is experienced with one application of PVI. This suggests that new donor preparation methods do not impact tissue quality.
This is a 2020 ARVO Annual Meeting abstract.