Pre-Descemet’s Endothelial Keratoplasty (PDEK) is a new type of corneal transplantation that can be used for patients with swelling or edema of the cornea. This technique is a variation of Descemet’s Membrane Endothelial Keratoplasty (DMEK), and is less like Descemet’s Stripping Endothelial Keratoplasty (DSEK).
Watch this episode of A State of Sight with Isaac Porter, MD to learn more about this exciting new technique. This method was first reported by Dr. Amar Agarwal based upon ideas that Professor Harminder Dua first developed when he discovered a previously unknown Dua’s layer of the cornea.
Welcome to A State of Sight, I’m Isaac Porter and this is your weekly update in ophthalmology and eye care. Today I would like to tell you about a new, great technique for corneal transplantation Pre-Descemet’s Endothelial Keratoplasty or PDEK.
This was recently published in next month’s British Journal of Ophthalmology by Dr. Amar Agarwal. It is is a new form of inner layer corneal transplantation. Currently, the two primary methods are DSEK, Descemet’s Stripping Endothelial Keratoplasty and DMEK, Descemet’s Membrane Endothelial Keratoplasty.
If you look back at A State of Sight #26 I compare these techniques to show the differences between them. With DMEK patients have been shown to obtain better vision. However, the Descemet’s Membrane that is transplanted (the very inner layer in the back part of the cornea) is very thin and it can be a difficult to handle since it will naturally curl up on it self. This can make surgery more difficult to place the transplant in the correct place inside the eye.
Based upon findings that were reported last year from Professor Harminder Dua in England, PDEK is possible. Prof. Dua discovered a previously unknown sixth layer of the cornea called Dua’s Layer. He suggested that this layer could help support an inner layer corneal transplant if it was included with the graft. (See A State of Sight #68 for more information on Dua’s layer.)
With these thoughts in mind, an excellent surgeon, Dr. Amar Agarwal harvested corneal tissue including Dua’s layer and performed PDEK. He created the term Pre-Descemet’s Endothelial Keratoplasty because another name for Dua’s layer is Pre-Descemet’s layer. This means that this layer is just in front of Descemet’s membrane.
With this technique, the graft is more easy to handle, it does not curling upon itself quite as much, and it can be easier to put into the eye and stabilize inside the eye. Initially, the findings from five patients were published, and it looks like they have had great results so far.
In the long run, this may also offer the potential for better vision for the patients and may be an easier and more repeatable technique for surgeons than DMEK. With time we hope to see that eye banks can provide this tissue for surgeons to make it more widely available. Of course it will need to be researched and studied more.
If you have any questions about this exciting new technique please post, we will be happy to answer them. We hope to see you again soon next time on A State of Sight.