Description

Mnemonic for Ophthalmic Artery: DR MCLESSI

• D: Dorsal Nasal Artery – communicates with the angular artery of the facial artery.
• R: Central Retinal Artery – supplies the retina.
• M: Muscular branch of ophthalmic artery – supplies extraocular muscles and gives off:
  • Anterior Ciliary Artery:
    • Gives off a conjunctival branch for the vascular zone of the conjunctiva.
    • Gives off a branch for the major arterial circle.
• C: Long and Short Posterior Ciliary Artery – pierces the eye from the back, lies in the choroid, and forms:
  • Major Arterial Circle (MAC).
  • Minor Arterial Circle (Intramuscular Arterial Circle – IMC).
• L: Lacrimal Artery – supplies the lacrimal gland.
  • Lateral Palpebral Artery.
• E: Ethmoidal Artery:
  • Anterior Ethmoidal Artery – enters the anterior cranial fossa, supplies the anterior meninges, and passes through the cribriform plate to the nasal cavity.
  • Posterior Ethmoidal Artery.
• S: Supraorbital Artery – passes through the supraorbital foramen to the forehead, anastomoses with the frontal branch of the superficial temporal artery.
• S: Supratrochlear Artery – passes through the frontal foramen to supply the skin and muscles of the forehead.
• I: Internal or Medial Palpebral Artery.

Ocular Circulation

• Major Arterial Circle of Iris (MAC):
  • Formed by the Long Posterior Ciliary Artery and a branch of the Anterior Ciliary Artery.
  • Supplies the iris and ciliary processes.
• Intramuscular Arterial Circle (IMC):
  • Formed by the branch of the Anterior Ciliary Artery and the Short Posterior Ciliary Artery.
  • Supplies the outer and posterior part of the ciliary muscles.

Nasal Blood Supply

• Anterior Ethmoidal Artery.
• Posterior Ethmoidal Artery.
• Sphenopalatine Artery.
• Greater Palatine Artery.
• Superior Labial Artery.

These arteries anastomose at the nasal septum, forming Little’s Area (Kisselbach’s Area), the common site of nosebleeds.

Blood Supply of the Eyelids

Superior Palpebral Arch and Inferior Palpebral Arch are formed by:

• Medial Palpebral Artery.
• Lateral Palpebral Artery (from Lacrimal Artery).

Ophthalmic Vein

• Superior Ophthalmic Vein: Communicates with the angular vein as the nasofrontal vein.
  • Central Retinal Vein drains the retina.
• Inferior Ophthalmic Vein: Communicates with the angular vein.
  • Gives off a branch to the pterygoid plexus.
  • Gives off a branch to the superior ophthalmic vein.

Varicose Veins: Two superior and two inferior veins contribute to the major arterial circle and intramuscular arterial circle in the choroid.

Sources Used:

• Memorix Anatomy (2nd Edition) – Hudák Radovan, Kachlík David, Volný Ondřej.
• Complete Anatomy by 3D4Medical.
• Biorender.
• University Notes and Lectures.

Transcript

Introduction
0:03
What’s up, Meditay here and In this video, we’re gonna talk detailed
0:07
about the vascular supply of the eyeball We’ll start with the ophthalmic artery and
0:11
then quickly run through the veins So – I wanna start here because
0:15
orientation is everything, really. If we look at the lateral view of the skull,
0:19
And remove the frontal and zygomatic bone We’ll be able to see the ethmoidal bone
0:25
And the optic canal, from which the ophthalmic artery comes from. Now I want
0:29
you to take a mental picture Of this specific area
0:32
Because I’ve simplified it in order to map the artery easier
0:36
So the ethmoidal bone and the optic canal is here, and for orientation sake
0:41
The lacrimal gland is here on the upper lateral region of each orbit
0:46
Now The ophthalmic artery comes through the optic
0:49
canal and stays on the medial side of the Eye No, for the branches,
Mnemonic for Ophthalmic Artery
0:54
I like to use DR MCLESSI as a mnemonic Arranging them like this, our first side brach
Dorsal Nasal
1:00
Is the dorsal nasal. I kinda slipped off the tongue here saying it’s a side branch
1:02
The dorsal nasal is more of a terminal branch of the ophthalmic artery.
1:07
It goes out at the medial corner of each Eye. And then communicates with the angular artery,
1:13
as you see here, which comes from the facial artery of the external carotid.
1:17
So that’s this one Next is the R, R for Central Retinal Artery
Central Retinal Artery
1:23
It pierces the eyeball together with the optic nerve and then
1:27
Branches off supplying the retina So – remember the layers of the Eye?
1:32
There’s first the sclera, then the choroid, and then the retina. So as you see here,
1:38
the artery branches out specifically to the retina Next is the M
Muscular Branches
1:44
For the muscular branch, Supplying the external muscles of the Eye
1:50
So remember you got 4 rectus muscles – or straight muscles, and two oblique muscles.
1:56
One on the top and one on the bottom. The artery will supply all of them
2:01
and then give off an important branch called the anterior ciliary artery,
2:05
which forms a vascular zone under the conjunctiva of the Eye. And it doesn’t really do that alone.
2:11
The posterior ciliary artery will pierce the eyeball from the posterior side
Long and Short Posterior Ciliary Arteries
2:17
And contribute to the vascular supply Of the eyeball. And I wanna spend a minute
Ocular Circulation
2:24
To tell you about this circle as it’s really important
2:27
So again, here are the three layers of the eyeball. The sclera, choroid, and retina
2:33
Up here you have the conjunctival membrane which is a mucosal membrane covering the sclera
2:38
and then there’s the cornea covering the anterior side of the Eye.
2:42
With the Iris here And the Lens.
2:44
And of course, there’s the Ciliary body and the suspensory ligaments.
2:48
So that’s the general anatomy. But essentially from the extraocular muscles,
2:54
remember The anterior
2:56
ciliary artery goes out to then supply The conjunctiva; contributes to the vascular
3:02
zone of the conjunctiva. And you see this a lot Those are the superficial vessels between the
3:08
conjunctiva and the sclera you see grossly on the Eye
3:11
But the anterior ciliary also has branches to the major arterial circle of Iris.
3:18
And remember I just mentioned the posterior ciliary arteries?
3:21
Both short and long Posterior ciliary arteries lie in the choroid part of the eye
3:26
The long ones will help contribute to this circle
3:30
And the short ones will form a small arterial circle
3:33
Called the intramuscular arterial circle, So Zooming into this area
3:39
This is how it really looks like. Supplying the structures of the Eye, like the Iris,
3:43
and the ciliary body, and the choroid, and so on. We’ll get back to this again later
3:47
in this video when we go through the veins because there’re gonna be veins here as well.
3:51
So that’s these two. Next L for lacrimal artery
3:56
Supplying the lacrimal gland. It does have one important side branch called the
4:01
Lateral Palpebral artery supplying the lateral part of the eyelids. Next E
Anterior/Posterior Ethmoidal Artery
4:07
For Ethmoidal Arteries. There are the Anterior and posterior ones
4:12
They run through the ethmoidal foramen, as you see here.
4:16
They both eventually end up in the nasal cavity, but the
4:19
Anterior ethmoidal will first run through the anterior cranial fossa to supply
4:24
The anterior meninges. Then it’ll go down through the cribriform plate
4:29
To meet up with the posterior ethmoidal – supplying the nasal cavity. They contribute to
4:35
Form a plexus of arteries in the nasal septum called kisselbach’s area or
4:40
Little’s area. This is the area that you usually rupture when you have a nosebleed.
4:45
It’s formed by the greater palatine and the sphenopalatine of the maxillary artery and
4:50
the superior labial of the Facial artery and the ethmoidal arteries of the ophthalmic. So… that’s
4:58
These. Next Supraorbital
5:01
Artery, which Goes upwards
5:03
Through the supraorbital fissure. It supplies the skin and muscles of the forehead, and
5:10
Anestemose with the frontal branch of the superficial temporal artery.
5:15
Then we got one similar, called the supratrochlear artery
5:18
Which also passes upwards But through the frontal foramen,
5:22
which is a little medially to the supraorbital fissure.
5:26
The supratrochlear artery will also supply the skin and muscles of the forehead.
Blood Supply of the Eyelids
5:31
The last letter, I, stands for internal, or medial palpebral artery,
5:36
Which goes out on the medial side of the Eye Forming a superior and inferior palpebral arch
5:43
together with the Lateral palpebral artery, supplying the eyelids.
5:47
So that’s mainly it for the ophthalmic artery. Let’s quickly do the veins. The venous drainage
Ophthalmic Vein
5:53
Happens with the help of the superior and inferior ophthalmic vein Draining into the cavernous sinus
6:00
From the superior ophthalmic vein comes the central retinal Vein
6:04
Going together with the central retinal artery to drain the retina from blood
6:09
Then there’s the Vorticose veins. Two from
6:12
the superior and two from the inferior side. Remember I showed you this scheme of ciliary
6:18
arteries making up the major and minor arterial circle?
6:21
The varicose veins contribute to this, draining most structures of the eyeball.
6:26
So these are very important. Now Essentially both the superior
6:30
and inferior ophthalmic vein drain from the angular vein, which comes from the facial vein.
6:36
The superior drain from it as the nasofrontal vein, but the inferior will divide into 2 branches
6:43
One branch will join the pterygoid plexus through the inferior orbital fissure.
6:48
While the other branch will connect with the superior ophthalmic vein.
6:52
So that’s a brief look at the vascular supply of the eyeball.
6:56
I really hope you found this video helpful until next time.