DMEK: the Grand Prix of cornea transplant surgery

Abstract

Descemet membrane endothelial keratoplasty (DMEK) is the most recent iteration of endothelial keratoplasty. With DMEK, restoration of true corneal anatomy is achieved. The majority of outcomes of DMEK surpass those of any of its predecessors – visual acuity, speed of recovery, refractive shift and stability as well as immunologic rejection are all better than before. As surgical techniques are continuously being refined, so endothelial cell densities and complications rates are steadily improving. All of these account for DMEK gaining popularity with corneal surgeons as well as patients suffering from corneal endothelial disease. This review highlights the recent advances in this exciting field of corneal surgery and addresses current challenges and contentious issues.

Keywords::

• cornea transplantation
• Descemet membrane endothelial keratoplasty
• DSAEK
• DSEK
• endothelial cell density
• endothelial keratoplasty
• immunologic rejection
• keratoplasty
• primary graft failure
• re-bubble
• refractive shift

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• Diseased recipient Descemet membrane and endothelial cell layer are replaced with healthy donor Descemet membrane and endothelial cell layer, thus resulting in restoration of true corneal anatomy.

• Regardless of the surgical technique used, the following principles should be adhered to:

  • – No ophthalmic viscosurgical device/viscoelastic should be in the anterior chamber or tissue injector prior to donor insertion;

  • – Correct orientation of the tissue is crucial to obtaining a successful outcome; the surgeon should be comfortable and confident with the technique he/she uses to confirm this;

  • – With a near-total air or gas (sulfur hexafluoride) fill of the anterior chamber, a patent peripheral iridotomy is mandatory to prevent pupillary block.

• Typical outcomes at 6 months are:

  • – Best spectacle corrected visual acuity ≥20/25: 75% of patients;

  • – Mean refractive shift: +0.4D (hyperopic shift);

  • – Endothelial cell density loss: 32%.

• Detachments are the most common complication. These are managed by re-bubbling and criteria based on the status of the graft at 1 week postoperatively are most helpful.

• Reported rejection rates are much lower than Descemet stripping automated endothelial keratoplasty.

• Primary graft failure rates vary widely but closely correlate with the surgeon’s learning curve.

• Descemet membrane endothelial keratoplasty is best performed in uncomplicated eyes. In cases where anterior chamber anatomy is compromised or in the setting of a previous vitrectomy, Descemet stripping automated endothelial keratoplasty, and not Descemet membrane endothelial keratoplasty, should rather be attempted.

Notes