Abstract
Purpose :
To evaluate the utility of regional Endothelium/Descemet’s complex (En/DM) thickness (rDMT) in the diagnosis of active corneal graft rejection.
Methods :
Thirty-six eyes (24 corneal grafts; 12 clear grafts and 12 with active rejection, along with 12 age-matched control eyes) were imaged using high-definition optical coherence tomography (HD-OCT; Envisu R2210, Bioptigen, Buffalo Grove, IL, USA) with 6 mm radial cuts centered on the corneal vertex. Custom-made segmentation algorithm was used to segment the En/DM, and 6 mm bullseye maps were created and divided into three regions; central, paracentral and peripheral (Fig. 1). The mean thickness of each region was calculated. One-way ANOVA with post-hoc comparisons were performed to compare the means of central, paracentral, and peripheral rDMTs between the three groups. Receiver operating characteristic curves were generated to determine the sensitivity and specificity of the central, paracentral, and peripheral rDMTs in differentiating between the studied groups (Fig. 2).
Results :
The mean central rDMTs for the control, clear, and active rejection groups were (10, 12, and 28 µm, respectively), the mean paracentral rDMTs were (11,16, and 29 µm, respectively), and the mean peripheral rDMTs were (14, 19, and 37 µm, respectively). The mean central, paracentral, and peripheral rDMTs were significantly higher in the active rejection group than both the control, and clear groups (p<0.005). On the other hand, there was no significant difference in the central rDMTs between the control and clear groups (p=0.25). However, peripheral and paracentral rDMTs were significantly higher in the clear grafts than the control group (p=0.04, and p=0.01, respectively). Peripheral rDMTs achieved 100% sensitivity and specificity (optimal cut off value, OCV, of 26 µm; area under the curve, AUC, of 1) in differentiating the actively rejecting grafts from both clear and control groups, while both central and paracentral rDMTs achieved 100% sensitivity and 96% specificity (OCV of 17.5, 20µmm, AUC=0.998).
Conclusions :
Peripheral, central, and paracentral rDMTs are novel signs for the diagnosis of corneal graft rejection. Peripheral rDMTs have excellent accuracy in differentiating active corneal rejection from clear corneas and normal eyes.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.