BLOOD AND NERVE SUPPLY OF EYE
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The document details the blood supply and nerve innervation of the eye and optic nerve, highlighting contributions from the internal and external carotid arteries and various branches. It describes the anatomy of the arterial supply including the central retinal artery, ciliary arteries, and their respective functions, as well as venous drainage pathways. Additionally, it outlines the sensory and motor nerve supplies involved in eye sensation and movements, emphasizing the roles of cranial nerves.
BLOOD AND NERVE SUPPLY OF EYE
- 1. BLOOD AND NERVE SUPPLY OF EYE AND OPTIC NERVE Presenter – Dr. Om Patel Moderator – Dr. Rashi Sharma
- 2. Arterial supply • Internal carotid artery • External carotid artery
- 3. Arterial supply • All structures are supplied by branches of Internal Carotid Artery • Except eyelids and conjunctiva which receives blood supply from the branches of both internal and external carotid artery
- 6. Post.Ciliary (supply the choroid and parts of the optic nerve) Internal carotid a. Supratrochlear a. & Dorsal Nasal a. Ant. ethmoidal a. Post. ethmoidal a. Ophthalmic a. Lacrimal a. Muscular Branches. (Ant.ciliary arteries are derived from it) Central Retinal Art. Branches of ophthalmic artery:
- 7. Central retinal artery • First branch from the ophthalmic artery • End arteries • Divides into equal superior & inferior branches, then another division (nasal & temporal)
- 8. Central retinal artery Runs along optic nerve, then at about 1.25cm behind eyeball it pierces the dural & arachnoid sheaths of optic nerve, enters eyeball through lamina cribrosa
- 9. Central retinal artery 9 Meningeal Branches Central Collateral Branches Pial Sheath Macular Nerve Fibres
- 10. Two Ciliary arteries (on each side of the optic nerve) • Divide into 2 long posterior ciliary arteries and ~20 short posterior ciliary arteries • The short posterior ciliary arteries directly supply the choroid and take part in formation of Circle of Zinn • The long posterior ciliary arteries travel in the suprachoroidal space anteriorly then supply the choroid anteriorly via recurrent branches Ciliary arteries
- 11. Circle Of Zinn • Circular anastomosis between short posterior ciliary arteries when they are piercing the sclera • Gives branches to choriod, optic nerve and pial network • Cilioretinal artery – helps to maintain vision in case of CRA occlusion
- 12. Anterior Ciliary arteries – 7 arteries 2 for each rectus muscle except LR muscle – Takes part in formation of Major arterial circle along with long posterior ciliary artery – Supplies ciliary body and iris
- 13. Eyelids • Arterial blood supply: – Lateral Palpebral artery (from lacrimal artery) – Medial Palpebral artery ( from dorsal nasal artery) • Marginal and peripheral palpebral arcades
- 14. Venous drainage: • Medially: to angular vein • Laterally: to superficial temporal vein
- 15. Nerve supply: Sensory Supply • Lower lid: – infra-orbital (from V2) – Medial Aspect infra- trochlear nerve (V1) • Upper lid: – Supra-orbital nerve – Supra-trochlear nerve – Lacrimal nerve (v1)
- 16. Nerve Supply - Eyelids • Arrangement of sensory nerves – Submuscular plane – Site of injection for anesthesia • Motor Supply – Facial Nerve – Orbicularis muscle – Oculomotor nerve – LPS
- 17. Conjunctiva • Palpebral conjunctiva marginal and peripheral arcades (from medial and lateral palpebral artery) • Bulbar conjunctiva anterior and posterior conjuctival arteries
- 18. Conjunctiva • Venous drainage: – superior and inferior ophthalmic vein • Nerve supply: – Long ciliary nerve (nasociliary branch of ophthalmic nerve)
- 19. Blood supply of the AC Long posterior ciliary artery anastomose with anterior ciliary artery – Major arterial arcade (ciliary stroma) – Minor arterial arcade (At the collarete of the iris) • They are the major blood supply to the iris and ciliary body • Venous drainage: minor venous circle directly into the vortex veins (not into the corresponding major circle)
- 21. Macula Region Supplied by Superior & Inferior temporal branches of central retinal artery **In 20% population Cilioretinal Artery supplies macula.(in case of CRA occlusion it helps to retain vision) • Outer-plexiform layer • CRA + partially by choriocapillaries • Inner nuclear layer, Inner Plexiform Layer, Ganglion cell layer, Nerve Fibre Layer, Internal Limiting Membrane • Supplied by Central Retinal Artery • RPE, Rodes and Cones ,External Limiting Membrane, Outer Nuclear Layer • Supplied by choriocapillaries Retina
- 22. Venous Drainage Of Eye • No valves • Tortuous & freely anastomose with one another
- 23. Venous Channels • Superior ophthalmic vein • Inferior ophthalmic vein • Middle ophthalmic vein • Medial ophthalmic vein • Angular Vein • Cavernous Sinus
- 24. Venous drainage of eye
- 25. Superior ophthalmic vein • Formed by union of supraorbital & angular veins • Communicates with Central Retinal Vein, receives Inferior Ophthalmic Vein & 2 vorticose veins from the upper part of the eyeball • Leaves the orbit through superior orbital fissure to join the cavernous sinus
- 26. Inferior Ophthalmic Vein • Arises from venous plexus in orbital floor • Communicates with pterygoid venous plexus • Receives muscular branches & 2 inferior vorticose vein • Joins superior ophthalmic vein or drains directly into the cavernous sinus
- 27. Angular Vein • Formed by supratrochlear and supraorbital veins • Runs down the side of nose about 8 mm from the medial canthus • Important landmark for lacrimal sac surgery • Continues as facial vein
- 28. Blood supply of Optic Nerve: A. Intraocular part/ optic nerve head • Cilioretinal artery • Peripapillary choroidal vessels • Vessels from zinn and heller Surface nerve fiber layer and Prelaminar part • Short Posterior Ciliary Arteries Lamina cribrosa region • Central retinal artery • Pial vessels Retrolaminar
- 29. Periaxial System Axial System Derived From branches of ICA Derived from branches of Central Retinal Artery Ophthalmic Artery Cental Retinal Artery Long posterior ciliary artery Central collateral branches Short posterior ciliary artery Intraneural branch Lacrimal Artery Central Retinal Artery B. Intraorbital part :
- 30. • The anterior portion of the nerve derives its blood supply from the posterior ciliary arteries (PCA) and the choroid (C) • The posterior optic nerve derives its blood supply from penetrating pial arteries (Col br) and branches of the central retinal artery (CRA)
- 31. C .Intracanalicular part : Periaxial system of vessels D . Intracranial part : Pial system of vessels
- 32. Venous drainage : Optic nerve head • Central retinal vein Orbital part • Peripheral pial plexus • Central retinal vein Intracranial part • Pial plexus which ends in anterior cerebral & basal vein
- 33. NERVE SUPPLY • Sensory N/S – *Trigeminal nerve (Mixed nerve) V *Ophthalmic (V1) & Maxillary(V2) divison play main role of eye sensation • Motor N/S -- *Cranial nerve 3rd ,4th,6th for ocular movements *Cranial nerve 7th for eyelid closure • Sympathetic N/s --* Nasociliary branch of ophthalmic nerve • Parasympathetic N/S:-- * Occulomotor (3rd)
- 34. TRIGEMINAL NERVE OPHTHALMIC MAXILLARY MANDIBULAR
- 35. •SUPRA-ORBITAL •SUPRA-TROCHLEAR •Ant.Ethmoidal –----- Supplies Ethmoidal Sinus •Post.Ethmoidal ------ Supplies Sphenoidal Sinus •Infratrochlear -------- Medial Eyelid •Long Ciliary Nerves---Pierces Sclera & Supply Cornea, Iris, Ciliary Body •Sympathetic Fibres---Dilate Pupil Supply Forehead + Scalp + Conjunctiva + upper & central eyelid Supplies to lateral eyelid + lacrimal gland + conjunctiva OPHTHALMIC Frontal Nerve Lacrimal Nerve Nasociliary Nerve
- 36. The nerves of the orbit that enter through the superior orbital fissure and supply the ocular muscles : • Oculomotor (CN III) • Trochlear (CN IV) • Abducent (CN VI)
- 37. Thank You