Abstract
Purpose :
A severe imbalance exists in the supply and demand of corneas world-wide.1 Given the imbalance, it is critical to maximize the utilization of procured corneas. Current standard of care screening of donor corneas is with the slit lamp, which provides limited information to distinguish infectious infiltrates from sterile opacities. Optical coherence tomography (OCT) may be useful as it has better depth resolution and could potentially better characterize corneal opacities. In this pilot study, we sought to characterize donor tissues with opacities and determine relative changes in their thickness.
1. Gain, P. et al. Global Survey of Corneal Transplantation and Eye Banking. JAMA Ophthalmol. 134, 167–173 (2016).
Methods :
22 donor corneas at Miracles In Sight eye bank were found to have an opacity on slit lamp exam and diverted for research. Using OCT (Leica EnVisu R4300), the donor corneas were scanned within their sealed sterile containers immersed in Optisol GS. The scan protocol consisted of 1000 A scan x 100 radial B scans spanning 10mm diameter. Opacities and other pathologic features were identified in the OCT images, and the relative thickness of opacities in the corneas were assessed using ImageJ.
Results :
All 22 corneas had opacities near the inferior limbus on slit lamp exam (Figure A). On the OCT images, all opacities were easily identified by increased reflectivity (Figure B). On OCT, twenty (90.9%) corneas had increased thickness in the area of the opacity (range 2.4-36.8%, mean 14.9%) when compared to adjacent clear cornea, and 2 corneas showed no change in thickness. Seventeen (77.3%) corneas had epithelial defect over the area of opacities. Seventeen (77.3%) corneas had opacities confined to the anterior 50% of the cornea.
Conclusions :
Donor corneal thickness is increased optically in the presence of opacities. OCT can be used to assess small changes in corneal thickness that may be difficult to evaluate using slit lamp exam lone. OCT was able to localize the opacity in depth within the cornea. Additional work, such as histopathology studies, are needed to determine the underlying etiology of the opacities and understand their correlation with the observed changes.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.