Abstract
Purpose :
In this study, we aim to study the roles of Disabled-2(Dab2) in anterior segment development of the eye. Specifically, we further characterize the mechanism of Dab2-deficiency in corneal opacification, which phenotypically resembles the congenital corneal opacities, such as Peters’ anomaly.
Methods :
Dab2 null mutant mice were generated and investigated to determine the functions of Dab2 in vivo. The corneal developmental abnormality was examined by anterior segment spectral-domain optical coherence tomography(SD-OCT) and histology. Dab2 GFP-reporter mice were used to trace Dab2 expression during eye development.
Results :
Two ocular phenotypes were observed in the Dab2 null mice: fused eyelid with an encrypted eye (cryptophthalmos) and corneal opacity (leukoma). Dab2 homozygous null conditional knockout mice eyes stained by Periodic acid–Schiff (PAS) indicated that grossly observed opaque corneas were morphologically thicker and harbored severe cellular infiltration compared to Dab2 heterozygous corneas.SD-OCT images revealed that corneal iris attachment in Dab2 CKO mice and the angles between the iris and cornea are smaller in Dab CKO mice. Measured by tonometry, we found that IOP was elevated in Dab2 CKO mice with opacity but not those with normal appearing cornea. By Dab2-GFP reporter, we found Dab2 was expressed in the corneal stroma and endothelial cell layer, limbus, iris, and ciliary body.
Conclusions :
Dab2 plays roles in several aspects of anterior segment development with various penetrance, resulting in several eye phenotypes observed in Dab2 null mice, including encrypted eye or cryptophthalmos defects, cornea-iris attachment issues, and advancing corneal opacity.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.