Endothelial keratoplasty — DMEK, DSAEK, PK

The surgical principle was transformed by the shift from penetrating keratoplasty to posterior lamellar surgery: instead of replacing the whole corneal thickness, only the diseased tissue is substituted. The thinner the graft, the more healthy tissue is spared and the better the optical quality — at the cost of more delicate handling.

8.1 DMEK — the reference

Descemet membrane endothelial keratoplasty (DMEK) transplants Descemet membrane bearing its endothelium alone. It restores near-native anatomy, offers the best visual recovery (often ≥ 20/25), induces few aberrations, and has the lowest rejection rate of all keratoplasties (~1–2%/year). The trade-off is a demanding preparation and unscrolling. Technical points: SCUBA preparation, orientation marking ("S-stamp" to avoid upside-down implantation), unscrolling and gas tamponade (air/SF6). Graft detachment is the main complication, with re-bubbling needed in ~15–30% of cases.

8.2 DSAEK — the robust compromise

DSAEK transplants the endothelium and its Descemet with a thin lamella of posterior stroma. Technically more forgiving, it remains excellent for complex eyes (aphakia, glaucoma tube, altered iris); it caps visual quality slightly and induces a mild hyperopic shift from the added stromal lenticle. Ultra-thin (UT-DSAEK, < 100 µm) variants approach DMEK optics.

8.3 Penetrating keratoplasty (PK) — residual indications

Full-thickness grafting has yielded first place but retains a role with associated stromal opacity, repeated failure, or anatomy precluding lamellar surgery. It carries higher risk of rejection, astigmatism and suture-related issues.

Cell therapy & tissue engineering

Graft scarcity and the non-regenerative nature of the endothelium drive donor-independent approaches.

The most advanced is intracameral injection of cultured endothelial cells combined with a ROCK inhibitor that promotes adhesion (Kinoshita): transparency has been durably restored in endothelial dysfunction, a single donor potentially supplying several recipients.

Upstream, tissue engineering aims to fabricate the graft. TEEK seeds endothelial cells on an ultrathin, transparent, biocompatible carrier, yielding a transplantable monolayer using an already-mastered technique. 3D bioprinting pushes toward automated production: controlled monolayer deposition, cells derived from pluripotent stem cells (iPSC), dedicated bioinks (hyaluronic acid, gelatin), with functional markers (ZO-1, Na⁺/K⁺-ATPase). Preclinical work, but a path to a donor-independent "bespoke" endothelium. Alongside, the synthetic artificial endothelial implant (EndoArt), donor-independent, has shown favourable results in chronic edema — draining water mechanically without restoring cellular function.