Purpose: First, to present a new classification of epithelial transplantation procedures for ocular surface disease; second, to present our experience with a keratolimbal allograft procedure for limbal stem cell deficiency; and third, to make recommendations for the indications and postoperative management of epithelial transplantation procedures.
Methods: A review of all epithelial transplantation procedures was performed. A classification of these procedures based on the source of donor tissue and the tissue transplanted was proposed. In addition, a review of 25 eyes of 21 patients who underwent a keratolimbal allograft was completed. Ocular surface stability, improvement of visual acuity, success of subsequent keratoplasties, and preoperative risk factors were evaluated. Results were compared with those of other epithelial transplantation procedures for ocular surface disease. On the basis of the results of published studies, as well as ours, a recommendation for the indication of the various procedures was made.
Results: Epithelial transplantation for ocular surface disease can be classified as one of the following procedures: conjunctival autograft (CAU), conjunctival allograft (CAL), conjunctival limbal autograft (CLAU), cadaveric conjunctival limbal allograft (c-CLAL), living related conjunctival limbal allograft (lr-CLAL), or keratolimbal allograft (KLAL). Evaluation of our keratolimbal allograft patients revealed that 18 of 25 eyes (72%) developed a stable ocular surface. Fifteen eyes (60%) demonstrated a significant improvement in visual acuity. Persistent epithelial defects and symblephara were successfully managed with this procedure. Six of 13 (46%) subsequent keratoplasties were successful. Patients with limbal deficiency due to Stevens-Johnson syndrome had a significantly worse outcome. Patients with preoperative conjunctival keratinization also had a significantly worse outcome. Indications for epithelial transplantation are as follows: For patients with unilateral cicatrizing conjunctival disease, the first option should be CAU. For patients with unilateral limbal deficiency, CLAU is the procedure of choice. For patients with bilateral disease Ir-CLAL should be considered first. If this procedure is not available, then consideration of KLAL is warranted.
Conclusions: Classification of the various epithelial transplantation procedures based on anatomy is useful for an accurate comparison and discussion of the procedures. KLAL is a useful technique in the management of severe ocular surface disease due to limbal deficiency. However, patients with preoperative conjunctival keratinization have a poor prognosis. Consideration of a CLAU or a Ir-CLAL should be made for ocular surface disease on the basis of whether the disease is unilateral or bilateral. The importance of HLA and ABO typing, as well as the protocol for immunosuppression in the allograft procedures for limbal deficiency, needs further study.