Purchase this article with an account.
C.F. Inglehearn, M.D. Mohamed, L.M. Downey, I.G. Simmons, C. Thaung, L.R. Bridges, G.W. Roberston, D.H. Lester, D.W. Burt, P.M. Hocking; Blindness Enlarged Globe (beg), a recessively inherited mutation in chickens . Invest. Ophthalmol. Vis. Sci. 2004;45(13):3588.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: To report conservation of the beg chick mutant, described twenty–two years ago and to document the phenotype. The original report described a phenotype of blindness at hatch and globe enlargement in adult birds. Methods: A breeding colony was established and maintained at the Roslin Institute, Edinburgh. Birds were subjected to ophthalmic, morphometric and histopathological examination to confirm and extend observations in the original report. Results: beg homozygotes have significantly greater axial lengths and near doubled eye volumes. No significant difference in intraocular pressures was observed between blind and sighted birds, as measured by a tonopen. Full ophthalmic examination revealed chorioretinal atrophy with marked pigmentary changes, an absent or sluggish pupillary response, atrophy of the pecten and peri–papillary retina and iris neovascularisation. Several birds had high refractive error. Older birds had cataract, which, in the oldest cohort, was present in an injected eye with prominent iris vessels and an irregular unreactive pupil, reminiscent of rubeosis iridis. The oldest birds also occasionally demonstrated deposits on the lens capsule reminiscent of pseudoexfoliation. Pathological examination showed RPE clumping and loss of photoreceptors, with preservation of the inner nuclear, inner plexiform and ganglion cell layers. Conclusions: Analysis of the beg chicken mutant reveals a complex phenotype which is clinically distinct from existing chick eye mutants.
This PDF is available to Subscribers Only