A Surgical Cryoprobe for Targeted Transcorneal Freezing and Endothelial Cell Removal

Figure 3

SEM of the endothelium of transcorneally frozen pig corneas. (a) An untreated pig cornea with cell boarders in white showing a characteristic hexagonal mosaic. The outline if the cell nucleus is evident as a slightly lighter area within each cell. Scale bar, 10 μm. (b) A representative image taken at the same magnification of the freeze-damaged area after treatment with a 2.4 mm diameter/concave profile tip, illustrating severe damage to endothelial cells by freezing. Scale bar, 10 μm. (c and d) Lower magnification images of endothelial freeze-injured wounds showing circular areas of endothelial cell damage including some endothelial debridement, exposing Descemet’s membrane (c): 2.4 mm diameter/concave profile cryoprobe (scale bar, 200 μm); (d): 3.4 mm diameter/concave profile cryoprobe (scale bar, 500 μm). As expected, the larger probe induces more widespread damage (see Table 1 also). (e–h) Transition zones between unfrozen endothelial cells and those that were destroyed by freeze injury are often sharp (e) and (g); same area but different magnification (scale bars,10 μm, apart from (g) which is 50 μm).

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