A Comparative Morphometrical Study of the Pecten Oculi in Different Avian Species

Abstract

In this study was investigated the structure of pecten oculi in the ostrich, duck, pigeon, turkey, and starling. The pecten oculi of the ostrich was vaned type and made up primary, secondary, and few tertiary lamellae. However, duck, pigeon, turkey and starling had a pleated-type pecten oculi which displayed folded structure. The numbers of pleats of the pectens were 12, 13-14, 21-22, and 17 in duck, pigeon, turkey, and starling, respectively. Light microscopic investigation demonstrated that pecten oculi is basically composed of numerous capillaries, large blood vessels, and pigment cells in all investigating avian species. Capillaries were 20.23, 14.34, 11.78, 12.58, and 12.78 μm in diameter in ostrich, duck, pigeon, turkey, and starling, respectively. The capillaries are surrounded by thick basal membrane, and pigmented cells were observed around the capillaries.

Macroanatomic, light, and electron microscopic examination of pecten oculi in the seagull (Larus canus)

“…Location of pecten oculi of the seagull which is a diurnal bird was detected similar to the literature (Jasinski, ; Braekevelt, ; Braekevelt, ; Kiama et al, ; Braekevelt, ; Kiama, Maina, Bhattacharjee, & Weyrauch, ; Kiama et al, ; Rahman et al, ; Orhan et al, ; Gültiken, Y?ld?z, Onuk, & Karayigit, 2012; Rajab, ; Dayan & Ozaydın, ; Onuk et al, ; Pourlis, ). However, some differences were determined in terms of the size and pleat numbers.…”

Histological analysis of the eyeball of Neotropical birds of prey Caracara plancus, Falco sparverius, Rupornis magnirostris, Megascops choliba and Athene cunicularia

“…The vascular structure of pecten oculi observed in all studied species matches with its functions already reported by other authors. Its vascular structure seems to be the responsible for vitreous and retina nutrition and oxygenation in birds (PETTIGREW et al, 1990;DAYAN;OZAYDIN, 2013).…”

Hemodynamics of the pectinis oculi artery in American pekin ducks (Anas platyrhynchos domestica)

“…Birds (class Aves or clade Avialae) have an intraocular anatomical structure called the pecten oculi . This structure is pigmented, vascularized, and morphologically classified into three types: (i) conical, found in kiwis; (ii) vaned, found in ostriches and rheas; and lastly (iii) pleated, found in all the other avian species including American pekin ducks . Conical and vaned types project from the optic disk into the vitreous body, and the pleated type is oriented along the remnants of the fetal fissure .…”

“…This structure is pigmented, vascularized, and morphologically classified into three types: (i) conical, found in kiwis; (ii) vaned, found in ostriches and rheas; and lastly (iii) pleated, found in all the other avian species including American pekin ducks . Conical and vaned types project from the optic disk into the vitreous body, and the pleated type is oriented along the remnants of the fetal fissure . The pleated form of pecten has been characterized using histology and electron microscopy and shown to have folds or pleats, held together by a bridge composed of capillaries supported by fibroblasts and pigment cells .…”

“…Conical and vaned types project from the optic disk into the vitreous body, and the pleated type is oriented along the remnants of the fetal fissure . The pleated form of pecten has been characterized using histology and electron microscopy and shown to have folds or pleats, held together by a bridge composed of capillaries supported by fibroblasts and pigment cells . Furthermore, there are pecteneal hyalocytes attached to the retinal inner limiting membrane and in direct contact with the convoluted vessels of the pecten …”