Abstract
Purpose :
Surgical trauma is a key culprit of reduced postoperative corneal endothelial cell (CEC) density. In an effort to minimize cell loss, new techniques and tools are continuously being developed. A material’s ability to maintain CEC viability remains a top priority for all designs. Utilizing a novel testing platform, corneal buttons were subjected to compressive and shearing mechanical forces (simulating contact forces due to tissue manipulation or insertion) with borosilicate glass or stainless steel indenters.
Methods :
Fresh central porcine corneal buttons 8 mm in diameter were trephinated, labeled with live/dead cell indicators, and mounted in a custom device while submerged in a bath of BSS. A 3 mm diameter glass (n = 4) or stainless steel (n = 5) bead was displaced against the endothelium until a prescribed compressive force was measured. Immediately afterwards, a sinusoidal oscillatory motion was applied to the specimen. CEC viability was assessed via fluorescence imaging before and after the application of mechanical forces. Total number of injured/dead cells and total area of stripped cells were quantified within a region of interest.
Results :
Indentation with stainless steel beads resulted in larger areas of CEC stripped from the Descemet’s membrane as compared to glass beads or sham (no indentation). Stripped cells tended to conglomerate near the edges of viable cells in groups, rather than fully detaching themselves. CECs indented with glass beads remained on the endothelium, with sporadic sections of smaller stripped areas also observed. This resulted in a greater total number of injured cells being present.
Conclusions :
Our results demonstrate that stainless steel beads strip large areas of CEC completely, reducing the total number of injured cells present, an effect opposite to that of glass. These two contrasting cell loss patterns could influence the behavior of remaining neighboring viable CECs. Our data would suggest that new device designs should take consideration of the materials they are made from, especially if they will directly interact with CEC.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.