Keratoprostheses, artificial cornea & artificial endothelium
When tissue grafting is doomed to fail — repeat failures, deeply vascularised cornea, dry or keratinised surface, severe bilateral limbal deficiency — the corneal prosthesis offers rehabilitation where nothing else works.
| Device | Concept | Indications |
|---|---|---|
| Boston KPro type 1 | PMMA optic + back plate, mounted on a carrier graft; wet-surface eye | Multiple graft failures, relatively preserved surface |
| Boston KPro type 2 | Trans-palpebral variant for a severely diseased surface | Extreme dryness, keratinisation |
| CorNeat KPro | Synthetic prosthesis bio-integrated into the sclera via a non-degradable matrix (tissue colonisation) | A less tissue-dependent alternative; 1st implantation in France and in Europe in 2021 (Pr E. Gabison) |
| OOKP (osteo-odonto-KPro) | Autologous tooth/bone support carrying an optical cylinder | End-stage cicatricial dry eye (Stevens-Johnson, burns) — last resort |
▶ Watch the CorNeat KPro and artificial cornea on video (egabison.com)
The price of this rehabilitation is lifelong surveillance: retroprosthetic membrane, glaucoma (often the main long-term visual threat), extrusion/melt of the carrier graft, and above all the risk of endophthalmitis. Selection, close follow-up and adherence (bandage contact lens, antibiotic prophylaxis) are inseparable from the indication.
Synthetic bio-integrated prostheses aim to reduce dependence on donor tissue and to improve long-term retention through cellular colonisation of the material — a convergence of prosthetics and tissue engineering.
EndoArt® — the artificial endothelium (synthetic device)
For a long time, "artificial cornea" meant replacing the optical axis (keratoprosthesis). EndoArt® (EyeYon Medical) transposes this synthetic logic to the posterior layer: it is an artificial endothelial implant, a thin flexible lens of hydrophilic acrylic apposed to the posterior surface of the cornea. It does not replace the endothelial pump but acts as a mechanical barrier preventing aqueous humour from soaking the stroma, reducing oedema — with no donor tissue at all.
Niche indication: symptomatic chronic corneal oedema in patients with low visual potential, after repeated endothelial graft failures, or when donor tissue is lacking. CE-marked; positioned with a gas bubble, repositionable.
| Advantages | Limitations / drawbacks |
|---|---|
| No donor tissue: free of scarcity and immunological rejection | Mechanical barrier only: does not restore endothelial pump function |
| Available "off the shelf", standardised and repositionable implant | Reserved for selected cases (often limited visual potential) |
| An option when endothelial grafting has failed or is impossible | Requires good apposition/fixation; risk of decentration or dislocation |
| Minimally invasive and reversible procedure | Long-term follow-up still limited |
The first EndoArt® implantation in France was performed by Pr E. Gabison and Pr B. Cochener.
Surface reconstruction & limbal grafting
A keratoplasty only succeeds on a healthy epithelial surface. In limbal stem cell deficiency (chemical burns, aniridia, Stevens-Johnson, iatrogenic causes), the corneal epithelium can no longer renew itself: conjunctivalisation, neovascularisation, opacification. Restoring the limbal reservoir is then a prerequisite for any stromal graft.
| Technique | Source | Situation |
|---|---|---|
| CLAU / conjunctivo-limbal autograft | Healthy fellow eye (autologous) | Unilateral involvement |
| CLET (Holoclar®) | Autologous cultured limbal stem cells | Unilateral deficiency; 1st stem-cell therapy medicine authorised in Europe (EMA) |
| SLET | Simple limbal epithelial transplantation (small autologous fragment placed on amniotic membrane) | Low-cost, single-stage alternative |
| KLAL / lr-CLAL | Allograft (cadaveric or living related donor) | Bilateral involvement — under immunosuppression |
| Amniotic membrane | Healing / anti-inflammatory scaffold | Frequent adjunct |
▶ Watch a report on ocular surface reconstruction (egabison.com)
Grafting the stroma onto a surface with limbal deficiency is programming failure: persistent epithelial defect, neovascularisation, rejection. Reconstruct the surface first, graft afterwards.