Abstract
Purpose: :
To study the anatomy of the DLEK wound using optical coherence tomography.
Methods: :
OCT (OCT3, Carl Zeiss Meditec Inc.) was performed on 5 eyes of 5 patients with a diagnostic of Fuchs’ dystrophy or PBK, before and after DLEK. Surgery was also performed on 4 post–mortem eyes for a more extensive analysis of the patterns encountered. Vertical and horizontal central corneal images were obtained with the OCT, followed by 4 additional radial measurements perpendicular to the wound at 12:00, 3:00, 6:00 and 9:00. An image was also taken at the level of any wound anomaly documented at the slit lamp. Image acquisition and manipulation were adapted to anterior segment analysis. The following parameters extracted from the OCT images were analyzed: (1) Gap between donor and recipient edges, (2) Donor recipient thickness mismatch (step), (3) Wound compression, (4) Detachment of the graft, and (5) Differential corneal thicknesses. Attempts were made to describe subepithelial fibrosis in oedematous corneas and postoperative interface quality, two aspects more difficult to document with the slit lamp.
Results: :
The mean depth, width, and contour of the gap observed between donor and recipient edges were 272 µm (130 to 460 µm), 173 µm (60 to 260 µm), and 685 µm (380 to 980 µm), respectively. The vertical step between the donor and recipient edges ranged from –180 to 40 µm (mean: –89 µm). Wound compression, represented by warm colors at the edges, was found in one patient and was about 280 µm wide. One case of mild graft detachment was observed. The average residual recipient central thickness was 328 µm and the average donor thickness was 220 µm, which represented 60% and 40% of the total thickness, respectively.
Conclusions: :
Non contact corneal OCT allows interesting quantitative characterization of the anatomy of the DLEK wound.
Keywords: transplantation • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • gap junctions/coupling