Whole globe enucleation versus in situ excision for donor corneal retrieval--a prospective comparative study

The purpose of this study was to compare the results after changing from conventional whole globe enucleation to in situ excision of donor corneas.

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.

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.

Changeover from whole globe enucleation technique to in situ excision technique of harvesting donor corneas demonstrated that in situ excision is a viable alternative.