Keratoplasty options

While the field of corneal transplantation has been transformed in recent years by the introduction of lamellar keratoplasty (LK) techniques, there are still indications where traditional penetrating keratoplasty (PK) may provide better optical or therapeutic results, according to Pierre Fournié MD. “Although LK has gained popularity over the past few years, PK remains a commonly performed transplantation technique in eyes with both anterior and posterior corneal disease, and is now limited to use in diseases where the benefit of replacing all the diseased tissue will provide the best optical or therapeutic results compared with LK,” Dr Fournié told delegates at a joint EuCornea-ESCRS symposium during the XXXIV Congress of the ESCRS in Copenhagen, Denmark. The advantages of PK include the fact that it is an established standardised technique with a short operation time and a long-term follow-up available in the scientific literature, said Dr Fournié, University Hospital Toulouse, France. The disadvantages of PK include the fact that it involves working on an open eye with the risk of expulsive haemorrhage, suture complications, high and irregular astigmatism, endothelial immune reaction, and idiopathic chronic endothelial cell loss which may result in late graft failure, he added. These drawbacks help to explain the rise of LK, which offers increased postoperative structural stability, reduced astigmatism, reduced rehabilitation time, reduced immunological graft rejection and increased graft survival time for many indications.

PK remains a useful option for certain indications such as full-thickness corneal scars

Nevertheless, PK remains a useful option for certain indications such as full-thickness corneal scars because of abnormalities involving all layers of the cornea, severe corneal trauma, or after the resolution of infectious keratitis involving all layers of the cornea, said Dr Fournié. “Corneal imaging is also very useful in some cases to assess corneal thickness and the depth of the diseased cornea to help us choose between different techniques,” he added. For paediatric keratoplasty, most indications now call for lamellar procedures, said Dr Fournié, with some notable exceptions including Peters anomaly or sclerocornea. “In such cases PK can be very useful and successfully restore corneal transparency and visual function, even if we still have some concerns about the long-term graft survival,” he said. He noted that paediatric keratoplasty should be performed as soon as necessary to correct amblyopia but as late as possible to ensure better patient cooperation and reduced complications. “We know that we have decreased graft survival with young patients and especially for children under the age of five and especially during the first 24 months,” he said. Beyond paediatric keratoplasty, PK is also the preferred procedure in cases where a temporary keratoprosthesis has been used for retinal detachment repair. The prosthesis is replaced with a PK graft after completion of the retinal procedure which usually works quite well, he said. Although lamellar techniques such as Descemet’s stripping automated endothelial keratoplasty (DSAEK) and Descemet’s membrane endothelial keratoplasty (DMEK) are now preferred for most diseases involving endothelial dysfunction, PK may still be an option for certain indications, said Dr Fournié. He cited examples such as eyes with long-standing chronic corneal oedema and significant corneal scarring, and particularly cases of diffuse corneal stromal opacity. PK may also be an option in ‘complicated’ eyes such as those with open communication between the anterior and posterior segments (large iridectomy and aphakia). Although deep anterior lamellar keratoplasty (DALK) is now the preferred technique in keratoconus, some exceptions where PK might be employed include post-hydrops cases when Descemet’s membrane cannot be bared, with central corneal scarring or persistent corneal oedema. PK can also be used in eyes with concomitant keratoconus and endothelial abnormality such as Fuchs’ dystrophy or posterior polymorphous dystrophy, concluded Dr Fournié. Pierre Fournié: fournie.p@chu-toulouse.fr