Abstract
Purpose: :
To compare microstructural differences in fresh corneal tissue with glycerin-cryopreserved corneal tissue (GCCT) used during deep anterior lamellar keratoplasty (DALK).
Methods: :
The medical records of 48 patients who underwent DALK for stromal opacity without endothelial abnormalities were retrospectively reviewed. Patients were divided into 2 groups according to corneal tissue used, a fresh corneal tissue group (n=22) and a GCCT group (n=26). Slit-lamp, corneal topography, pachymetry, and laser scanning in vivo confocal microscopy examinations were performed at 2 weeks and 1, 3, 6, 12, and 24 months postoperatively..
Results: :
No rejection developed in the GCCT group. Stromal rejection developed in one eye (4.2%) in the fresh corneal tissue group. In 19 eyes (73.1%) in the GCCT group, the best-corrected visual acuity (BCVA) was 6/12 or better compared with 17 eyes (77.3%) in the fresh corneal tissue group at 24 months. The median spherical equivalents in the GCCT and fresh corneal tissue groups were, respectively, -2.46 and -1.81 at the final visit. There were no significant differences in BCVA, spherical equivalent, astigmatism, central corneal thickness, or endothelial cell density between the groups at 24 months. While progressive significant (P<0.05) reductions in keratocyte density in the central stroma developed at each examination in the fresh corneal tissue group, the GCCT group had progressively increasing keratocyte density from 3 months, but no cellular structures were observed at 2 weeks and 1 month. Confocal scanning showed only subbasal nerve fiber bundles in the fresh corneal tissue group (10 eyes) and the GCCT group (14 eyes) until 24 months postoperatively.
Conclusions: :
DALK using GCCT provides results comparable to fresh tissue. GCCT can be used safely and effectively for DALK and may minimize stromal rejection postoperatively.
Keywords: transplantation • cornea: stroma and keratocytes • microscopy: confocal/tunneling