Penetrating limbo-keratoplasty for granular and lattice corneal dystrophy: survival of donor limbal stem cells and intermediate-term clinical results.

PURPOSE: To assess clinical follow-up data, and to identify donor epithelial cells after homologous penetrating central limbo-keratoplasty in patients with granular and lattice corneal dystrophies compared with patients who underwent conventional penetrating keratoplasty (PK). DESIGN: Mixed retrospective and prospective nonrandomized comparative case series. PARTICIPANTS AND CONTROLS: Twenty-six patients who underwent 33 limbo-keratoplasty procedures for granular or lattice corneal dystrophy since May 1995 and a historical control group of 24 patients who underwent 36 PK procedures between November 1986 and May 1995. METHODS: Postoperatively, all but 2 limbo-keratoplasty patients were treated with systemic immunosuppressants for 6 months. All patients received long-term topical immune prophylaxis with prednisolone-21-acetate 1% (2 drops per day). After obtaining informed consent, epithelial cells were harvested from 10 limbo-keratoplasty eyes of 8 patients with granular dystrophy and 7 limbo-keratoplasty eyes of 7 patients with lattice dystrophy. Conjunctival epithelium or buccal mucosal epithelium for recipient identification and corneal epithelial cells from 3 graft sites were harvested. Deep-frozen donor corneoscleral rims were analyzed to characterize donor features. Genetic analysis was performed by polymerase chain reaction of short tandem repeat (STR) loci. MAIN OUTCOME MEASURES: The ratio of dystrophy recurrences in the graft was clinically assessed. Donor features in epithelial cells were genetically established if at least 1 STR profile differed from that of the recipient. RESULTS: There were 5 recurrences in limbo-keratoplasty eyes with granular dystrophy and 2 recurrences in limbo-keratoplasty eyes with lattice dystrophy, compared with 15 and 6 recurrences in PK eyes, respectively. The differences between limbo-keratoplasty and PK were not statistically significant over time (log-rank test; P = 0.14 for granular dystrophy and P = 0.56 for lattice dystrophy; alpha error, 0.05). For genetic analysis, 12 of 17 samples were evaluated. Donor epithelial cells were detected in 5 of the 12 samples (42%). CONCLUSIONS: Limbo-keratoplasty tended to be associated with fewer recurrences of granular and lattice dystrophies. However, the difference was not yet statistically significant, probably due to the disappearance of the transplanted limbal stem cells over time. Genetic analysis confirmed the survival of transplanted limbal stem cells over several years in some limbo-keratoplasty eyes, which might correlate with less recurrence. Limbo-keratoplasty, therefore, is likely to represent a first step towards long-term recurrence-free survival of corneal grafts in patients with granular and lattice dystrophies.

Long-term results of allogeneic penetrating limbo-keratoplasty in total limbal stem cell deficiency.

OBJECTIVE: To determine the prognosis of allogeneic penetrating limbo-keratoplasty in patients with total limbal stem cell deficiency and to find out if donor limbal stem cells survive in the long run. DESIGN: Noncomparative prospective case series. PARTICIPANTS: Forty-eight patients with total limbal stem cell deficiency. INTERVENTION: Allogeneic penetrating limbo-keratoplasty. All patients received systemic cyclosporin A and/or mycophenolate mofetil in the postoperative course. Thirteen patients received grafts with 0 to 1 HLA mismatches in the HLA-A, HLA-B, and HLA-DR loci; 13 patients received grafts with 2 to 6 mismatches; and 22 patients received untyped grafts. MAIN OUTCOME MEASURES: Long-term clear graft survival and survival of donor limbal stem cells. RESULTS: Five years postoperatively, 65% of the grafts with 0 to 1 mismatches, 41% of the grafts with 2 to 6 mismatches, and 14% of the untyped grafts were clear centrally (estimation according to Kaplan-Meier log rank test, P = 0.03). Immunogenetic analysis of epithelial cells from the surface of the graft could be performed successfully in 7 of 9 patients and revealed donor DNA in the epithelium of 5 of these 7 patients up to 56 months postoperatively. CONCLUSIONS: Long-term survival of donor epithelium could be demonstrated immunogenetically in patients undergoing allogeneic penetrating limbo-keratoplasty. Human leukocyte antigen-matched grafts seem to deliver better results than untyped grafts. Progress with matching and immunosuppressive strategies may further improve current results.