Corneal transplantation has undergone a quiet revolution over the past two decades. The era of full-thickness penetrating keratoplasty (PKP) — with its long recovery, sutures, and relatively high rejection risk — is giving way to a new generation of tissue-selective techniques. DMEK represents the leading edge of this evolution, and in 2026 it is my preferred approach for the majority of patients with corneal endothelial disease.
What Is the Corneal Endothelium?
The cornea is a layered structure. Its innermost layer — the endothelium — is a single layer of cells whose primary function is to pump fluid out of the corneal stroma, keeping it clear. The human cornea has approximately 2,500 endothelial cells per mm² at birth. These cells do not regenerate. When endothelial cell density falls below a critical threshold, the cornea swells, becomes hazy, and vision deteriorates. Chronic pain and glare may follow.
The most common cause of endothelial failure is Fuchs endothelial dystrophy, a genetically inherited condition causing progressive endothelial cell loss. Other causes include surgical trauma (bullous keratopathy after cataract surgery), iridocorneal endothelial syndrome, and prior failed corneal transplants.
The Evolution of Corneal Transplantation
Understanding DMEK requires a brief look at how corneal transplantation has evolved:
Penetrating keratoplasty (PKP): Full-thickness replacement of the entire cornea. Requires 16–24 sutures. Recovery takes 12–18 months for vision to stabilise. Rejection rate 15–25% over 5 years. Still used for full-thickness corneal disease (scars, keratoconus in selected cases).
DSAEK (Descemet Stripping Automated Endothelial Keratoplasty): Replaces the Descemet membrane and endothelium with a thin layer of donor stromal tissue. Faster than PKP — vision typically stabilises by 3–6 months. Rejection rate approximately 10–15% over 5 years. Visual acuity limited by the residual stromal interface.
DMEK (Descemet Membrane Endothelial Keratoplasty): Transplants only the Descemet membrane and its endothelial cells — a tissue sheet approximately 10–15 microns thick. No stromal tissue is included. Rejection rate approximately 1–3%. Recovery typically 1–3 months. Best final visual acuity of all endothelial transplant techniques.
How Is DMEK Performed?
DMEK is performed as a day procedure under local anaesthesia. A small incision (approximately 3mm) is made at the corneal periphery. The recipient's diseased Descemet membrane is stripped from the inner surface of the cornea — this is the "D" in the procedure name. A carefully prepared scroll of donor Descemet membrane and endothelium is then injected into the anterior chamber through the same incision. The scroll unfolds, floats into position, and is held in place against the back of the cornea using a gas bubble injected into the anterior chamber.
In the post-operative period, patients lie face-up for approximately 45–60 minutes (and intermittently for the first day or two) to keep the gas bubble pressing the graft firmly against the cornea while it adheres. The bubble absorbs over 1–2 weeks. No sutures are required for the graft itself.
Who Needs DMEK?
DMEK is the procedure of choice for patients with isolated endothelial disease — where the front layers of the cornea (epithelium and stroma) are structurally normal and only the endothelial pump function has failed. The primary indications are:
- Fuchs endothelial dystrophy — the most common indication in Melbourne. A genetic condition causing progressive endothelial cell loss. Often presents in the 50s–70s with glare, foggy morning vision, and slow visual deterioration.
- Bullous keratopathy — endothelial failure following cataract surgery or other intraocular procedures
- Failed prior DSAEK or DMEK graft — re-grafting with DMEK is possible in selected cases
- Iridocorneal endothelial (ICE) syndrome
DMEK is not appropriate when the corneal stroma or epithelium is also significantly abnormal (for example, keratoconus, corneal scarring, or anterior stromal disease). In these cases, DALK (Deep Anterior Lamellar Keratoplasty) or PKP may be the preferred approach.
DMEK Outcomes — What to Expect
| Parameter | PKP | DSAEK | DMEK |
|---|---|---|---|
| Tissue replaced | Full thickness | Endothelium + thin stroma | Endothelium only |
| Rejection rate (5-yr) | 15–25% | 10–15% | 1–3% |
| Best corrected VA achievable | Variable | 6/9 to 6/7.5 | 6/6 or better |
| Recovery time | 12–18 months | 3–6 months | 1–3 months |
| Sutures required | Yes (16–24) | 1–2 | No |
| Incision size | Full circumference | 5mm | 3mm |
DMEK and Cataract Surgery — Combined Procedures
Many patients with Fuchs dystrophy also have cataracts. In appropriately selected patients, it is possible to perform combined DMEK and cataract surgery (Triple DMEK) at the same anaesthetic. This avoids two separate procedures and allows recovery from both simultaneously.
For patients with Fuchs dystrophy who require cataract surgery, timing and sequencing must be carefully planned. In some cases, cataract surgery alone can significantly improve vision if the endothelial disease is not too advanced. In others, DMEK is required first or simultaneously. I discuss this decision in detail with each patient based on their corneal measurements, endothelial cell count, and cataract severity.
For more information on cataract surgery options including premium IOLs, see corneaeyedoctor.com.au.
My Experience in DMEK
I was trained in corneal transplantation at the Royal Victorian Eye and Ear Hospital (RVEEH) — Australia's leading corneal referral centre — where I undertook a subspecialty fellowship in corneal and anterior segment surgery. I continue to operate on the RVEEH Cornea Unit as a Staff Specialist and perform DMEK, DALK, and PKP at Northpark Private Hospital, Bundoora.
For patients in Melbourne requiring corneal transplantation, I provide a detailed assessment to determine the most appropriate surgical approach, discuss realistic expectations for recovery and visual outcome, and manage care from pre-operative assessment through to long-term follow-up.