Purpose
To correlate optical coherence tomography (OCT) imaging with high frequency ultrasound images of the posterior pole in postmortem non-preserved donor tissue eyes.
Methods
Postmortem eye bank globes were enucleated using standard techniques and transported to the laboratory in saline soaked gauze moist chamber on ice. The fresh eyes were treated within 12 hours post mortem with topical drops of 10% phenylephrine and 1% tropicamide, given in two rounds, three minutes apart. The globes were oriented and secured to a Styrofoam head with the corneas facing forward; balanced salt solution was injected with a 32 gauge needle into the vitreous cavity approximately 4 mm posterior to the limbus to achieve physiologic pressure as measured by palpation. OCT raster line scanning (Heidelberg, Heidelberg, Germany) (OCT) images of the macula were obtained. The eyes were then reoriented in the Styrofoam head so the posterior pole was facing forward. A high-frequency (40 mHz) ultrasound biomicroscopy (UBM) probe (Ellex, Adelaide, Australia) covered with a water filled ultrasound transducer cover (ClearScan®; ESI, Inc., Plymouth, MN) was placed over the back of the eye to obtain images of the macula and adjacent retina. The eyes were fixed using a solution of 10% neutral formalin.
Results
Similar to previous studies, the pharmacologic agents increased the pupil diameter an average of 1.87 mm. OCT imaging of the macula identified much of the anatomy appreciated in an in vivo scan, although postmortem retinal changes imposed some limitations. The UBM showed recognizable retinal landmarks in the posterior pole and correlated well with pathology seen on the OCT images such as epiretinal membranes causing macular puckering.
Conclusions
UBM successfully imaged fine retinal structures in postmortem eyes. This additional technique can be used to screen postmortem eyes for disease-specific conditions.
Keywords: 552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) •
472 comparative anatomy