Abstract
Purpose :
Sharpness of corneal punches has direct impact on the endothelial and stromal surfaces of keratoplasty grafts. Here, we examined the topography of the surface of two commonly used donor cornea punches (Moria Busin Punch and Barron Punch) and the morphology of corresponding keratoplasty grafts.
Methods :
The blades of Moria Busin or Katena Barron donor punches were examined by scanning electron microscopy (SEM) and blade features documented. Subsequently, the punches were used to generate full-thickness corneal grafts from mate donor corneas. SEM images of the grafts were taken at every 2 clock hours to examine uniformity and smoothness of the graft edge. Additional images were collected of any tissue anomalies that may have been caused by features identified on the punches.
Results :
The Moria punch features a straight, double beveled blade rolled into a circular shape, resulting in the presence of a seam. The Barron punch features a single-beveled blade that is seamless due to its unibody design. Both blades exhibit multiple striations and fissures adjacent to the cutting edge of the blade, as well as debris, divots, and notches along the blade edge. Full-thickness cornea grafts generated with the Moria punch have regions of damage along the edge of the cut tissue and ridges of stroma. In contrast, full-thickness cornea grafts generated with the Barron punch were observed to have an even band of denuded tissue along the cut edge and a stromal surface lacking in extra ridges of tissue. The stroma of grafts generated with both punches exhibited “drag lines.”
Conclusions :
Features observed in each punch can be linked to features of the cut cornea tissue. The presence of a seam in the Moria punch may contribute to extra endothelial damage and creation of an uneven stromal surface in full-thickness cornea punches. Drag lines observed in the stromal surface of tissue cut with either the Moria or Barron punch may be related to multiple striations and uneven features present on the surface of both blades. It is possible that these topological features may result in uneven graft-recipient tissue apposition, leading to increased astigmatism or high order aberrations after penetrating keratoplasty. On-going analysis is aimed at examining endothelial cell loss at the graft edge associated with the use of these two punches.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.