• Cornea
• Vision
• Treatment Surgery

▸ Related article: 10.1136/bjophthalmol-2011-301349

Penetrating keratoplasty (PK) or full thickness corneal transplantation has enjoyed great success for over a century.1 ,2 Dramatic visual improvement can be achieved by this procedure but it is not without problems. Immune mediated rejection of the graft requiring long term topical or systemic immune-suppression, unpredictable degrees of astigmatism and a structurally weak eye susceptible to wound dehiscence following trivial trauma have remained major issues over the years.

Lamellar keratoplasty, wherein the anterior affected layers of the cornea are replaced by transparent donor tissue of equivalent thickness, has had a roller-coaster ride largely due to interface haze or scarring with consequent reduction in quality of vision. Recent advances in surgical techniques have propelled this operation to its highest crest. It is now possible to separate the Descemet's membrane and endothelium from the posterior stroma, allowing the replacement of the entire stroma thus eliminating the risk of graft failure secondary to endothelial rejection and making it virtually an extra-ocular procedure. Problems of astigmatism, sutures and structural weakness however remain.

Similarly for endothelial affections, it is now possible to replace the diseased endothelium through a small entry wound. This does not alter the astigmatism, requires minimal suturing and does not weaken the eye like a penetrating graft. The most popular procedures is the Descemet's stripping endothelial keratoplasty (DSEK) wherein the recipient endothelium is replaced with donor endothelium together with 100–150 microns of donor …