{'fraction_non_alphanumeric': 0.017699115044247787, 'fraction_numerical': 0.004424778761061947, 'mean_word_length': 5.383064516129032, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
The immunology of corneal transplantation.

There was considerable interest in corneal surgery, including grafting, in the early nineteenth century, but failure was universal because of a lack of understanding of immunology and corneal physiology. With improvements in asepsis and anaesthesia later in the same century, some progress was made, and the first successful human lamellar graft was performed in 1886 by von Hippel. The next 50 years saw further interest in the possibilities of corneal transplantation, and further (though rather crude) progress; but it was not until after the Second World War that most of the major advances were made, leading to a far greater chance of success. None of these advances has been more important than the development of immunology. Indeed, the cornea has been an excellent model for transplantation immunology in general. Following Maumenee'sl recognition that clinical rejection can occur, and the experimental work of Khodadoust and Silverstein2 that evaluated this in detail, we realize today that corneal graft rejection is the commonest cause of graft failure, and (now that most other difficulties have been largely overcome) it is by far the most taxing problem that remains. This chapter is designed to cover the relevant background of transplantation immunology with particular reference to the cornea, and it examines the pathogenesis and clinical forms of rejection. The clinical management and pharmacological treatment of rejection are considered, and some selected areas are discussed where further advances seem promising.