If DMEK or DSEK has been recommended to you, the names may sound unfamiliar and frightening. Let us take a calm look at them without complicated medical terminology. What are these operations, and why are they needed?
The cornea is the transparent part of the outer coat of the eye, rather like the glass over a watch face. Normally, you do not notice another person’s cornea because a healthy cornea is clear. Through it, you see the iris, which may be brown, blue, green, or another colour. Similarly, when you look at a watch, you see its face rather than the glass in front of it. But when the cornea becomes diseased, cloudy, and opaque, it becomes clearly visible. Severe corneal opacity is known as a leucoma, or a dense corneal scar.
The inner layer of the cornea, the endothelium, helps keep it transparent. If this layer stops functioning, for example because of Fuchs dystrophy or after surgery, the cornea becomes cloudy and swollen. Vision deteriorates, with haze, distortion, light sensitivity, watering, and, in advanced cases, severe pain.
In these situations, the problem lies not in the whole eye or the whole cornea, but in one specific inner layer of endothelial cells.
DMEK is the abbreviation for a procedure that replaces the patient’s endothelial cells with donor endothelial cells. Because these cells lie on Descemet’s membrane, that membrane is also transplanted as their supporting layer.
DSEK also replaces endothelial cells. Unlike DMEK, however, it transplants an additional layer of stroma along with the endothelium and Descemet’s membrane. This stromal layer is not itself needed for endothelial replacement, but makes the procedure simpler, although less effective.
You may see many similar abbreviations online and in scientific literature: DMEK-S, DMAEK, DSAEK, FS-DSEK, FLEK, and others. These are modifications of the basic DMEK and DSEK procedures, developed to make surgery faster or simpler, for marketing purposes, or for other secondary and sometimes only apparent advantages.

DMEK and DSEK are modern surgical methods in which:
The entire cornea is not replaced.
Only the damaged inner layer is transplanted or replaced.
The front surface of the cornea is left intact.
DMEK and DSEK are abbreviations for operations that replace endothelial cells.
This is currently the most precise, tissue-sparing, and physiologically appropriate approach. Older techniques, such as penetrating keratoplasty, were widely performed in the twentieth century and are now used much less often.

In very simple terms:
DSEK transplants a thin layer of tissue.
DMEK transplants an ultrathin layer, as close as possible to the natural anatomy: the thinnest possible graft.
DMEK is the most advanced technique and provides:
Faster visual recovery.
Better quality of vision.

• A lower risk of complications and rejection.

The choice of procedure always depends on the individual situation, the condition of the eye, previous operations, the surgeon’s skills, and many other factors.
DMEK and DSEK are mainly indicated for congenital, inherited, and acquired disorders of the endothelial cells and Descemet’s membrane. The most common indications include:
Fuchs endothelial dystrophy, an inherited condition.
Bullous keratopathy, an acquired condition arising from complications of cataract surgery, lens replacement, glaucoma, and other causes.
Endothelial failure after previous corneal transplantation.
Congenital hereditary endothelial dystrophy (CHED).

• Other endothelial conditions.

The operation is performed under an operating microscope.
The patient lies down.
No large incisions are needed.
The procedure takes relatively little time.
An overnight hospital stay is usually unnecessary.
During surgery, the damaged layer is removed and donor tissue is carefully positioned, after which the graft attaches and integrates.

DSEK and DMEK require:
Experience working with donor tissue.
Excellent skills in preparing an ultrathin graft.
A high degree of precision.
Extensive practical experience.
An understanding of possible postoperative issues and complications.
These are not routine operations: they involve extremely delicate structures of the eye and rely on skills developed over years.

• DSEK and DMEK are technically fundamentally different from other operations.

1. DMEK and DSEK are established operations, not experimental procedures or something to fear.
2. They are modern, proven methods that help restore vision in situations where treatment options used to be much more limited.
3. Even an excellent surgeon experienced in penetrating keratoplasty, cataract surgery, or vitrectomy does not necessarily have expertise in DSEK or DMEK. These procedures require specific skills and substantial experience.
4. At your consultation, we always discuss in detail:
Whether the procedure is suitable for you.
What alternatives are available.
What to expect from surgery and recovery.
The risks and possible difficulties.
5. I believe that doctor and patient are partners. I therefore aim to explain everything in simple, clear language, often drawing anatomical and surgical details, taking time to answer questions and giving each patient as much attention as needed. Our relationship is a dialogue rather than a hierarchy.