Histological Study of the Chicken Retina and Associated Ocular Structures

Abstract

Comparative ocular and histological studies is the high degree of development of the anatomical elements and superior visual acuity make the avian eye (particularly, the domestic hens) an ideal model to study. This study aimed to study the retina and other ocular structures of the domestic chicken (Gallus gallus domesticus) in histological point of view. Twenty samples of the eyeballs were taken out of healthy hens of approximately 40 days old and the weight range was 1.5-2.0 kg. The samples were processed like any other normal biological material, whereby they were placed in 10 percent neutral buffered formalin, dehydrated, and embedded like any other normal histological material. The overall architecture of the tissues in the sections was observed regarding hematoxylin and eosin (H&E) stain.

        At low and high magnification microscopic examination revealed the typical multilayered structure of the avian retina. Besides the five layers of cornea, other eye body tissues were discovered and documented including sclera (dense collagen fiber), scleral supportive cartilage, skeletal muscle bundles within sclera and the adjacent vascularized pigmented choroid to the retina. This research increases our understanding of the anatomy of chicken eye tissues and provides a foundation with which comparative and veterinary research on chicken eyes can build on