The
pecten or
pecten oculi is a
comb-like structure of
blood vessels belonging to the
choroid in the
eye of a
bird. It is a non-
sensory,
pigmented structure that projects into the
vitreous body from the point where the
optic nerve enters the
eyeball. The pecten is believed to both nourish the
retina and control the
pH of the vitreous body. High level of enzyme alkaline phosphatase activity in pecten oculi, has been linked to transport of nutrient molecules from highly vascularized pecten oculi into vitreous and then into retinal cells for nourishment. It is present in all birds and some
reptiles.