Eyeball Enlargement Induced by Monocular Iatrogenic Cataract in Chickens

ABSTRACT

In chicks, visual deprivation lead to myopia and enlargement of the vitreous chamber of the eye. In an attempt to elucidate the eyeball enlargement by iatrogenic cataract, two-day old white Leghorn chickens(n=28) were lightly anesthetized with ether and iatrogenic cataract was induced by YAG laser. The other eye was used as control group. Refractive error, corneal curvature, and axial length by ultrasonography were assessed before the study, and 3 weeks and 6 weeks after cataract formation. At 6 weeks, intraocular pressure, dimension changes and weight of enucleated eyeball were measured. The axial lengths in the iatrogenic cataract eye group were significantly larger than their control eyes in both the axial and the equatorial dimensions. Corneal sag and diameter, intraocular pressure, were not significantly different between two groups. We conclude that form vision deprivation with cataract induces the enlargement of the eyeball, especially the posterior segment of the eyeball.