Studies on Gross, Histomorphological, Histochemical and Ultrastructural Characteristics of Pecten Oculi in Guinea Fowl (Numida meleagris)

Pecten Oculi of Guinea fowl (Numida meleagris) was studied on their 18 eyes for gross, histological, histochemical and ultrastructural observations. The pecten oculi has 13 to 17 number of accordion (pectineal) folds. These accordion folds were initiated from cauda of optic nerve and travelled via fundus distally into the vitreous humour as an undulated pathway as snake. The shape of pecten oculi was not different than the water floating sail board. The maximum average length and height of pecten oculi was found on the tune of 3.378±0.061 mm and 5.913±0.074 mm respectively. Microscopically the pecten oculi showed an organization as the festoon of blood capillaries with their elastic, collagen and reticular fibers that were corresponding with the structure of spring diving board, which works after the Hook’s law. Melanocytes, melanosomes and melanin granules were observed in and around blood capillaries of pecten oculi. It has divided into three parts apex, middle one third and base. The highest concentration of melanin was observed in the apex. Histochemically the pecten oculi was shown very weak activity of acid and alkaline phosphatase. It had shown a strong activity of glycogen at optic nerve and collagen fibers of pectineal capillaries. Ultrastructurally, the nucleated erythrocytes were witnessed at luminal area of pectineal blood capillary with the tight intercellular endothelial junction. The primary and secondary lamellae were observed in the luminal region of pectineal capillary with pigment depositing globules. Pecten oculi of Guinea fowl has shown various anatomical features thereby it performs various functions as the organ of haemostatic utility, phagocytosis, providing source of energy to vitreous after the diffusion, protecting eye from ultraviolet sunlight radiation, supplementation of nutrition and provide oxygen to the retina to have visual acuity.