Keratoplasty has been, and still is, the queen surgery of the corneal specialty. This is explained by the importance of the cornea in vision and its very limited ability to return to normal, given the wide variety of pathologies that can affect it and leave irreversible sequelae, from trauma – including surgical – and infections, to degenerative diseases or dystrophies, so that often the only solution is to replace the diseased tissue. On the other hand, the practice of keratoplasty has been increasingly extended and it is no longer the prerogative of a few centers.

It is for this reason, a topic of undeniable interest for a growing number of our colleagues, and it is therefore surprising that, apart from the very timely requested Communications of 2005 and 2010, it has not been the subject of an Official Publication of SEO since, almost a quarter of a century ago, when Dr. José Temprano -whom we have the luck to count as a collaborator in this work- presented his "Keratoplasty and keratoprostheses".

During this time there have been great changes in the world of keratoplasty; some true revolutions. We changed centuries and, in addition to recording this fact -accidental, but perhaps for many hopeful, in the title we chose, we were also forced to change the grammatical number: Keratoplasty has become keratoplasties, since the boom experienced by this surgery in recent years is due in large part to the development of multiple new techniques, especially those of lamellar keratoplasty.

This work tries to offer the reader a summary of the recent information and the experience of the experts, as well as a reflection on the current state of the subject and future perspectives. For this, we have been fortunate to count on the collaboration of almost all those who stand out for their interest and dedication to keratoplasty in our country, as well as that, of a good number of the highest authorities in the world.

We have tried to follow a certain systematic approach, by which in each section - dedicated to one of the main modalities of keratoplasty (penetrating, anterior lamellar, endothelial, etc.) – we review its development and basic fundamentals, its indications, selection and preparation of the patients, the different surgical techniques, the special situations and the combined surgeries, the usual postoperative care, the intraoperative and postoperative complications, its prevention and treatment, as well as the results obtained and prognostic factors. Additionally, we have also included, for each one, a repertoire of clinical cases of special interest or complexity.

As another way of addressing certain issues, we have also included a series of practical questions to a number of national and international experts. In their answers one can find the different opinions on details or questions that often arise from a surgeon interested in this field.

The first section reviews general aspects, such as the concept and types of keratoplasty, their classification and terminology, the history of their development to this day, morphological and functional analogues of corneal tissues, and the modern imaging techniques - which are applied to all its phases: pre- post- and increasingly, intra-operatively-, as well as aspects that affect various modalities, such as the new concepts of corneal biomechanics or the special care in alterations of the ocular surface.

Then we devote a section to the eye banks, without which it would not be possible to perform keratoplasties: their modern organization, obtaining the donor tissue, their evaluation, their preservation techniques and their processing for the different types of keratoplasty.

The following sections deal with penetrating keratoplasty and lamellar keratoplasty, following the aforementioned scheme in each one. Due to the volume of the material they represent, we have divided the latter into several sections, which are dedicated to superficial anterior lamellar keratoplasty, deep anterior lamellar keratoplasty, endothelial lamellar keratoplasty and Descemet-endothelial keratoplasty. In addition to the photographic documentation, links to videos that illustrate the different aspects of the topics developed and special clinical cases are included.

The work also devotes a section to keratoprostheses, which can be considered within this field if we understand it in a broader sense than that of mere transplants. In it we detail the history and types of keratoprostheses used today, the different techniques, results, prognostic factors and complications of what is currently the last resort for many patients with complex corneal pathologies.

Finally, we find a section on the future of keratoplasty, in which chapters are developed on techniques still under investigation, such as the transfer or cultivation and injection of endothelial cells, the artificial corneas obtained by bioengineering, the possible medical treatments of endothelial pathology and the future of keratoprostheses.

In summary, a work that systematically gathers the current knowledge and perspectives of keratoplasty surgery, has been prepared for those ophthalmologists who wish to update themselves in the field or corneal surgeons who seek to deepen their clinical-surgical practice.