Fourier domain optical coherence tomography as a noninvasive means for in vivo detection of retinal degeneration in Xenopus laevis tadpoles.

Abstract

PURPOSE: To determine the efficacy of Fourier domain optical coherence tomography (FD-OCT) as a noninvasive, nonlethal method for detecting in vivo, pathologic signs of retinal degeneration in Xenopus laevis larvae. METHODS: A prototype OCT system using FD detection customized for tadpole imaging was used to noninvasively obtain retinal scans in two different transgenic X. laevis models of retinal degeneration. FD-OCT retinal scans were compared with laser scanning confocal micrographs of histologic sections of the same eye. Retinal thickness was measured in the histologic micrographs and compared with in vivo measurements acquired with FD-OCT. RESULTS: In vivo retinal images of X. laevis tadpoles were obtained that visualized the major retinal layers. FD-OCT successfully detected the ablation of rod outer segments (OS) in degenerating tadpole eyes. Measurements from FD-OCT and histology showed a decrease in retinal thickness in transgenic mutant tadpoles relative to the wild-type control. The accumulation of phagosomes from dying rod OS was also visualized in the retinal pigment epithelium (RPE) in a degenerating tadpole retina. CONCLUSIONS: This report demonstrates that FD-OCT is a viable technique for screening, diagnosing, and monitoring retinal degeneration in X. laevis tadpoles in vivo.