The purpose of this study is to investigate the use of anterior segment enhanced depth imaging (EDI) optical coherence tomography (OCT) for ex vivo lamina cribrosa (LC) imaging.Materials and Methods:
After removing anterior segment and vitreous, the optic nerve head (ONH) tissue of porcine eyes was placed on a customized eye holder for imaging. Serial EDI OCT B-scans (interval, ∼35 μm) of the ONH were obtained using anterior segment module of spectral-domain OCT. Various conditions were tested for better quality LC images. After EDI OCT, serial histologic sections were obtained (distance between sections, ∼5 μm). LC structures in OCT scans were compared with those in histologic sections. Three-dimensional LC reconstructions created using serial OCT scans were compared with LC structures in disc photographs.Results:
ONHs of 3 enucleated eyes were examined. The LC was more clearly imaged when the retina and part of the prelaminar tissue were removed (quality score, 39.01±3.30 vs. 26.40±5.85; P<0.001) and when the tissue was kept moist during imaging (quality score, 38.70±2.11 vs. 36.18±5.98; P<0.001). LC image quality was similar before and after fixation (quality score, 38.84±6.57 vs. 39.21±9.69; P=0.79). LC beams and part of retrolaminar glial columns identified in OCT scans matched those in histologic sections. LC beams and pores in 3-dimensional reconstructions matched those in disc photographs.Conclusions:
High-resolution cross-sectional images of the LC, comparable to histologic sections, can be obtained using anterior segment EDI OCT in ex vivo eyes with proper tissue preparation.