Endothelial keratoplasty — DMEK, DSAEK, PK

The shift from penetrating keratoplasty to posterior lamellar surgery narrowed the substitution to the diseased tissue alone, rather than the whole corneal thickness. 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.