What is the major blood supply of the retina?
The retina is supplied by the central retinal artery and the short posterior ciliary arteries (Fig 2.3). The central retinal artery travels in or beside the optic nerve as it pierces the sclera then branches to supply the layers of the inner retina (i.e., the layers closest to the vitreous compartment).
Which layer of the eyeball supplies blood to retina?
Choroid
Choroid. The thin, blood-rich membrane that lies between the retina and the sclera and is responsible for supplying blood to the retina.
What is the blood supply of choroid?
Blood is delivered to the choroid through the ophthalmic artery that branches to form (typically) two posterior ciliary arteries, 35 which in turn branch to form many short posterior ciliary arteries and two long posterior ciliary arteries.
How does blood get to the retina?
The central retinal artery brings fresh blood into the eye. It runs through a narrow channel inside of the optic nerve, entering the back of the eye. A branching network of arteries then spreads out from this artery across nearly all parts of the retina.
What are retinal blood vessels?
Description. The retinal blood vessels are the central retinal artery and vein, and their branches. The arteria centralis retinæ and its accompanying vein pierce the optic nerve, and enter the bulb of the eye through the porus opticus.
What is the blood supply to the eye?
An ophthalmic artery and a central retinal artery (an artery that branches off of the ophthalmic artery) provide blood to each eye. Similarly, ophthalmic veins (vortex veins) and a central retinal vein drain blood from the eye. These blood vessels enter and leave through the back of the eye.
What portion of the eye supplies blood supply to the other layers of the eye?
The choroid provides oxygen and nourishment to the outer layers of the retina. Along with the ciliary body and iris, the choroid forms the uveal tract.
What is the function of the fovea?
Structure and Function The fovea centralis is located in the center of the macula lutea, a small, flat spot located exactly in the center of the posterior portion of the retina. As the fovea is responsible for high-acuity vision it is densely saturated with cone photoreceptors.
Are blood vessels in the retina?
The retina has two sources of oxygen and nutrients: the retinal blood vessels and the choroid, which lies under the retinal pigment epithelium. The blood vessels within the retina itself that carry oxygen and nutrients are called arteries.
What is the blood supply of the optic nerve?
In the retrolaminar part of the optic nerve the blood is mainly supplied by the intraneural centrifugal branches of the central artery of the retina with centripetal contribution from the pial branches from the choroidal arteries, circle of Zinn, central artery of the retina, and direct from the ophthalmic artery.
Where does the blood supply to the retina come from?
Blood supply to the retina. There are two sources of blood supply to the mammalian retina: the central retinal artery and the choroidal blood vessels.
What does each layer of the retina do?
Each layer of cells in this tissue serves a specific purpose. As we prepare for Age-Related Macular Degeneration Awareness Month in February, a closer look at the layers of the retina and their function. Choroid – This is made up of a layer of blood vessels that supply oxygen and nutrients to the retina.
Where are the capillaries located in the retina?
Capillaries are found running through all parts of the retina from the nerve fibre layer to the outer plexiform layer and even occasionally as high as in the outer nuclear layer. Nutrients from the vasculature of the choriocapillaris (cc) behind the pigment epithelium layer supply the delicate photoreceptor layer.
Why is the central retina thicker than the peripheral retina?
Central retina close to the fovea is considerably thicker than peripheral retina (compare Figs. 9 and 10). This is due to the increased packing density of photoreceptors, particularly the cones, and their associated bipolar and ganglion cells in central retina compared with peripheral retina. Fig. 9.