Microscopic analysis of donor corneas to ensure the adequacy of endothelium cell density and absence of abnormalities or defects improves transplant success rate
When it comes to a corneal transplant it is not simply an eye for an eye, as scientists at the Bristol Eye Bank can testify. Suppliers of up to 1500 corneas a year, they have to be confident that each one will provide the best possible vision, and this calls for close analysis of every donor cornea to assess its viability.
It's a complex procedure, but one they can now do more accurately than ever before, thanks to a Leica DM LB microscope and image analysis system.
The success of a corneal graft is crucially dependent on the quality of the donor cornea's endothelium, a monolayer of cells lining its inner surface.
"These cells control corneal hydration and thus maintain transparency," explained Professor John Armitage, director of tissue banking, division of ophthalmology at the University of Bristol.
"Unfortunately, in humans corneal endothelial cells do not easily proliferate and every donor cornea needs to be examined by light microscopy to ensure the adequacy of the endothelium's cell density and absence of abnormalities or defects.
The evaluation process is currently at best semi-quantitative but the Leica DM LB will make the measurements much more reliable, reducing inter-operator variation and allowing better standardisation.
This system will provide far more information than we currently obtained and will be invaluable for monitoring the factors that influence the outcome of grafts, as well as allowing far better evaluation of storage methods for human corneas." Professor Armitage explained his reasons for choosing Leica: "The Leica system performed by far the best of those I evaluated.
The image quality of the microscope and the power and versatility of the image analysis program were of paramount importance but I also considered the ergonomics and ease of use in the initial evaluation.
The technical support and training options offered by Leica were also important considerations and I have found the representatives helpful, friendly and, above all, knowledgeable."
