Editor,—We read with great interest the recent article by Dua and Azuara-Blanco,1 describing the use of a new immunosuppressive agent FK-506 in patients receiving allo-limbal transplantation. The authors also describe a modified surgical approach. Although FK-506 appears to be a safe and effective treatment option in these patients, the follow up is longer than 1 year in only two of the six patients. These two patients experienced a limbal graft rejection episode in the postoperative period and we therefore feel that longer follow up is necessary before the efficacy of FK-506 can be properly established. It would also be interesting to compare FK-506 with cyclosporin A in future studies to assess the relative safety and efficacy of the two drugs.

The potential advantage of HLA matching was cited in the discussion by the authors. Although a recent study2 indicates that HLA matching may not totally obviate the need for immunosuppression, we believe that it will allow reduction of dosage and or duration of treatment with these potentially toxic drugs. In countries with a paucity of corneal donor tissue, where even hepatitis B positive donor …