Abstract
Background: :
A preliminary interview of potential donor families and health care workers in a major tertiary care hospital in North India revealed a far greater willingness for eye donation if the corneoscleral rim was excised by in situ excision rather than conventional whole globe enucleation. As the latter is predominantly the standard practice being currently followed and there are concerns of microbiological contamination in switching to the new technique, this study was undertaken.
Purpose: :
To compare the microbial contamination and clinical outcome of corneoscleral tissue obtained after changing from conventional whole globe enucleation to in situ excision.
Methods: :
Prospective evaluation of corneas retrieved by whole globe enucleation (Group 1) or in situ excision (Group 2) from 2002–2004 that were suitable for keratoplasty was done. Fifty pairs of eyes were studied (25 in each group). All corneas were stored in modified MK medium. One hundred optical keratoplasties were done and followed up for three months. The parameters evaluated were microbial contamination, median visual acuity, graft clarity, corneal pachymetry and endothelial cell counts.
Results: :
The preoperative disease distribution and visual potential were similar in the two groups. Mean donor endothelial cell densities were 2174 + 123 and 2132 + 149 (p=0.1) in Group 1 and 2 respectively. Postoperative corneoscleral rim culture results were statistically comparable in both groups (24% in group 1, 20% in group 2, p=0.62). The corneal pachymetry was higher with in situ group at day 7 (556 microns Group 1, 569 microns Group 2; p=0.01) and at day 90 (528 microns Group 1, 539 microns Group 2; p=0.01). The postoperative endothelial cell counts were lower for in situ group on day 7 (1745/mm3 vs 1805/mm3; p=0.02) and 90 (1674/mm3 vs 1708/mm3; p=0.18). The postoperative median visual acuity and graft clarity were comparable at day 7 and day 90.
Conclusions: :
Dissection of corneosceral rim in situ provides an acceptable alternative to the conventional enucleation technique without the increased risk of microbial contamination even in our part of the world. The slightly increased initial endothelial loss may be attributed to the associated learning curve in changing over to the new technique.
Keywords: cornea: clinical science • cornea: storage • cornea: endothelium