In my first blog entry we reviewed the basic structure of the cornea and process of performing a full-thickness corneal transplant.
There are many patients, however, in whom only a certain layer or layers of the cornea are damaged and need to be replaced. In fact, in Fuchs corneal dystrophy – the most common reason for corneal transplantation in the United States – only the innermost layer of cells in the the cornea (known as the endothelium) is abnormal. Over the past few decades, ophthalmologists have been developing new techniques for “partial thickness” corneal transplants that can produce better vision and better outcomes for this type of corneal disorder. DMEK and DSAEK (explained below) are two of these techniques.
What are the newest and most advanced corneal transplant techniques?
DSAEK stands for Descemet’s stripping automated endothelial keratoplasty. This procedure involves replacing the inner 20% of the cornea with a graft taken from a cornea donor. Over the last decade, this technique has significantly improved visual outcomes and has replaced PKP as the new standard of care for patients needing partial thickness corneal transplant surgery.
An newer development is a technique called DMEK. DMEK stands for Descemet’s membrane endothelial keratoplasty, a procedure that involves transplanting only a single layer of cells – only about 2% of the total corneal thickness! Of all the techniques described, DMEK is the newest and most technically difficult to perform, but it can result in better visual outcomes , lower rates of graft rejection, and faster healing than both DSAEK and PKP. Due to the difficulty in mastering this new technique, DMEK is not as commonly performed as DSAEK surgery. However, the excellent results with this technique have led more surgeons around the United States to begin performing DMEK in patients with Fuchs dystrophy and those with disease limited to the corneal endothelium (inner layer). For those patients who are not candidates for DMEK surgery, DSAEK or PKP techniques are also available.
1) Goldich Y, Showail M, Noa A, et al. Contralateral eye comparison of Descemet Membrane Endothelial Keratoplasty and Descemet Stripping Endothelial Keratoplasty. Am J Ophthalmol 2015;159:155-159.
2) Anshu A, Price MO, Price FW. Risk of corneal transplant rejection significantly reduced with DMEK. Ophthalmology 2012 Mar;119(3):536-40.
At Hill Vision Services, we are proud to be among the very first ophthalmology practices in the greater St. Louis area to provide DMEK surgery as an option for our patients with corneal disease. We are also proud to offer a full array of corneal and ocular surface disease expertise, including DSAEK, PKP, and other corneal surgery starting this August.
For any readers with questions or comments, please feel free to contact me, Dr. Geoffrey Hill, at firstname.lastname@example.org.
Also, for more in-depth information on Fuchs dystrophy, I encourage patients to visit the Fuchs Friends website at: http://www.fuchsdystrophy.orgfuchsfriends.htm