The best of times …

In this special issue of Clinical and Experimental Ophthalmology, we read reviews of the latest developments in corneal surgery techniques that show both new insights into the diseases we are treating as well as a series of technical advances that provide safer, more rapid and potentially superior functional outcomes for our patients. For corneal specialists, in terms of what we have to offer our patients, this is the best of times. For the past century, since the landmark case report of Eduard Zirm that first elucidated the principles of successful full thickness corneal grafting, penetrating keratoplasty has been the mainstay of corneal surgery for most disorders. The gradual evolution of successful penetrating keratoplasty was fuelled, in jumps and starts, by the miniaturization of surgical instruments, the development of monofilament nylon sutures, the operating microscope, understanding of the roles of the corneal endothelium and the key components of the ocular surface, the advent of topical corticosteroids and significant advances in eye banking. These collective contributions brought the penetrating corneal graft to a high level of success, most recently shown in the results of the Cornea Donor Study. Nonetheless, despite better than an 85% survival rate, the penetrating graft, even in experienced hands, is associated with complications including high corneal astigmatism, ametropia and anisometropia, suture-related infections, immune graft rejection, glaucoma and cataract. Even in the completely uncomplicated graft, the time from surgery until functional visual rehabilitation can be lengthy, often as long as 6–12 months. This time frame can have a major impact on the life of the young patient who is in the work force or the elderly patient for whom quality of life is an important and time-sensitive issue. We now live in the age of ‘selective’ keratoplasty in which layer-specific portions of the cornea are surgically replaced or modified. As such, there is currently a menu of new procedures developed for specific disease entities previously managed by penetrating keratoplasty. The enthusiasm for these procedures is prodigious, and already, for example, the number of endothelial keratoplasty procedures has more than tripled in the United States in the last 3 years. Likewise, many surgeons in Asia, Europe and the Americas are turning to deep anterior lamellar keratoplasty as the first choice of procedure for keratoconus when grafting is indicated. As might be expected, the impact of these procedures has also begun to modify eye banking standards and practices. As is often the case with new technologies and procedures, enthusiasm for novelty may trump data initially, and we are currently in the phase of sorting out technical modifications (e.g. the best way to insert an endothelial graft, the least complicated way of achieving complete Descemet’s baring), and longer-term outcomes and clinical efficacy (e.g. the FDA study of collagen cross-linking and monitoring of graft survival in endothelial keratoplasty). At each major meeting, our colleagues present new techniques and clever gadgets for tissue preparation and surgical manipulation as well as novel regimens for postoperative management of the new graft types. And simultaneously, there is a proliferation of papers in the clinical literature that codifies these findings. Accordingly, we are all immersed in learning the best ways of performing new techniques that are still not time tested but show immense promise. Endothelial keratoplasty: Since the presentation of posterior lamellar keratoplasty by Melles just over a decade ago, what is commonly referred to as endothelial keratoplasty is emerging as a standard for the treatment of visually significant endothelial dysfunction. Since that report, there has been a substantial proliferation of papers and books on Descemet’s Stripping endothelial keratoplasty or Descemet’s stripping automated endothelial keratoplasty. Even as methods and instruments to improve the insertion and adhesion of donor endothelium on a stromal carrier are being perfected, Descemet’s membrane endothelial keratoplasty as introduced by Melles is touted as providing even better visual outcomes, although techniques for safe and effective insertion of the membrane are still in evolution. Deep anterior lamellar keratoplasty: Historically, lamellar keratoplasty preceded penetrating keratoplasty, but the inferior visual results of the lamellar procedures made it less desirable. With the demonstration that stroma could be removed leaving only Descemet’s membrane to provide substantially improved visual performance, deep anterior lamellar keratoplasty brought renewed interest to the lamellar approach. Although technically challenging, the procedure offers many advantages including the elimination of endothelial rejection, earlier suture removal and therefore more rapid visual rehabilitation, as well as a lowered risk of postoperative would dehiscence. Moreover, a new pool of donor tissue (i.e. donor grafts with poor endothelium but clear stroma) has become available through the eye banks. Comparable visual results, a superior safety profile, and the broadening of the transplant tissue pool will be significant advantages as surgeons navigate the learning curve of this new/old procedure. Femtosecond laser assisted keratoplasty: The application of femtosecond laser technology beyond LASIK to the fashioning of a shaped keratoplasty wound or to the cutting of a lamellar graft (anterior or posterior) is an exciting development that, ultimately, may have significance in our surgical armamentarium. The challenge will be to show the Clinical and Experimental Ophthalmology 2010; 38: 91–92 doi: 10.1111/j.1442-9071.2010.02232.x