Abstract
Purpose: :
Detecting the microscopic structural changes in Descemet’s membrane of rejected penetrating keratoplasty (PK) and failed Descemet’s stripping automated endothelial keratoplasty (DSAEK) grafts and comparing that to functional grafts and normal age matched group.
Methods: :
The study included 17 eyes with functional PK grafts, 5 eyes with functional DSAEK grafts, 5 eyes with rejected PK grafts, 4 eyes with failed DSAEK grafts and 20 normal eyes as an age matched group. The microscopic structural characteristics of DM were detected in all examined eyes using custom-built ultra high resolution optical coherence topography with an axial resolution of 3 µm.
Results: :
DM of normal group (mean thickness: 16 ±2µm), functional PK (mean thickness: 16 ±4µm) and functional DSAEK groups (mean thickness: 16 ±2µm) showed strong structural similarities. DM in those three groups was visualized as two smooth hyper-reflective bands with no significant differences in terms of thickness. Despite that the DSAEK group had significantly thicker corneas than the normal and functional PK groups; DM thickness was not significantly thicker. DM thickness of rejected PK and failed DSAEK grafts showed thickening of the posterior hyper-reflective band of DM. Rejected PK graft mean thickness was 36 ±6µm, while rejected DSAEK grafts was 52 ±9µm, that represent a highly statistically significant thickening compared to normal eyes and functional grafts. Interestingly, despite that DM thickness of functional DSAEK and PK grafts was not significantly different, after failure DM of DSAEK grafts was significantly thicker than in rejected PK grafts.
Conclusions: :
DM of Rejected PK and failed DSAEK grafts showed characteristic microscopic structural changes. In-vivo detection of those changes using the UHR-OCT is a novel technique to detect graft status. Evaluation of the use of that novel technique in detecting subclinical graft rejection or failure is warranted.
Keywords: cornea: clinical science • imaging/image analysis: clinical • cornea: endothelium