Purpose: The purpose of this study was to compare the results after changing from conventional whole globe enucleation to in situ excision of donor corneas.
Methods: Donor corneal tissue retrieved by enucleation (n = 50) and in situ excision (n = 50) was quantitatively evaluated prospectively, and the main parameters evaluated were endothelial cell counts, ultrasonic corneal pachymetry, microbial contamination, graft clarity, and postoperative median visual acuity at the end of 3 months.
Results: Mean preoperative donor endothelial cell densities were 2174 +/- 123 and 2132 +/- 149 cells per millimeter square after enucleation and in situ excision, respectively (P = 0.13). The preoperative disease distribution and visual potential of recipients were comparable between the 2 groups. Corneal pachymetry was lower in the whole globe group at the end of 3 months (528 microm, enucleation group; and 539 microm, in situ group; P = 0.01). The mean postoperative endothelial cell counts were comparable in both groups at 3 months (1708 +/- 104.8/mm for whole globe group, measured in 40 eyes, vs 1674 +/- 117.4/mm in in situ group, recorded in 39 eyes; P = 0.18). The number of positive corneoscleral rim cultures postkeratoplasty was statistically comparable in both groups (20% in enucleation group and 24% in in situ group; P = 0.62). At 3 months, 98% and 92% of grafts had a graft clarity of >or=3+ in whole globe and in situ groups, respectively (P = 0.16). Seventy-two percent of patients in whole globe group and 67% in in situ group achieved a best-corrected visual acuity of >or=0.1. Postoperative graft infection developed in 2 cases in the in situ group.
Conclusions: Changeover from whole globe enucleation technique to in situ excision technique of harvesting donor corneas demonstrated that in situ excision is a viable alternative.