1. ORBITMARTIN EMMANUEL III RD BDS 2010 BATCH AL AZHAR DENTAL COLLEGE THODUPUZHA

2. CONTENTS INTRODUCTION BONY ORBIT CONTENTS OF ORBIT ARTERIAL SUPPLY OF ORBIT VENOUS DRAINAGE LYMPHATICS NERVE SUPPLY OF ORBIT CLINICAL ANATOMY REFERENCE 3. The orbits are bony cavities lodges and protects the eyeball, various muscles,nerves,blood vessels and lacrimal gland. THE RULE OF SEVEN They are bilateral,four sided ,pyramidal , box like spaces. INTRODUCTION 4. CONTENTS OF ORBIT 1.Eyeball :eyeball occupies anterior 1/3 of orbit 2.Fascia : orbital and bulbar fascia. 3. Muscles: extra ocular and intra ocular. 4. Vessels: ophthalmic artery,superior and inferior ophthalmic vein,lymphatics. 5. Nerves 6. Lacrimal gland 7.Orbital fat 5. ORBITAL MARGINS They are formed by three bones SUPERIOR ORBITAL MARGIN LATERAL MARGIN INFRAORBITAL MARGIN MEDIAL MARGIN 6. ORBITAL WALLS four walls two vertical (medial and lateral) and two horizontal (superior and inferior). 1.SUPERIOR WALL/ROOF: it is triangular in shape. it is formed by orbital plate of frontal bone and lesser wing of sphenoid bone. 2.LATERAL WALL :Thickest wall and is formed by orbital surface of the greater wing of sphenoid and the frontal process of zygomatic. 7. 3.INFERIOR WALL/FLOOR: it is shortest of all the four walls and is formed by orbital plate of maxilla,orbital surface of zygomatic and orbital process of palatine bone 4.MEDIAL WALL:it is flat or slightly convex towards the orbit and is formed by orbital plate of ethmoid,lacrimal,frontal process of maxilla and body of sphenoid. 8. CONTENTS OF ORBIT EYELIDS upper & lower eyelid palpebral fissure muscles orbicularis oris & levetor palpebrae superioris 9. SUSPENSORY LIGAMENT OF LOCKWOOD A facial sling connecting the two check ligaments and facial sheaths of inferior rectus and inferior oblique supports the eyeball from below like a hammock Layers & Function Clinical applicaton 10. LACRIMAL APPARATUS It is involved in production, movement and drainage of fluid from the surface of the eyeball It is made up of lacrimal gland , its ducts,the lacrimal canaliculi, lacrimal sac & nasolacrimal duct 11. EYEBALL Eyeballs are peripheral organs of sight and average diameter of 1 inch and is situated in the cavity of orbit. It consists of three coats 1.the external coat 2.the middle vascular and pigmented coat, the uveal tract 3.the internal nervous coat, RETINA. 12. EXTRA OCULAR MUSCLES: 1.VOLUNTARY MUSCLES : A)FOUR RECTI B)TWO OBLIQUI C) THE LEVETOR PALPEBRAE SUPERIORIS : elevates the upper eyelid. 2.INVOLUNTARY MUSCLES : A)SUPERIOR TARSAL MUSCLE B)INFERIOR TARSAL MUSCLE C)ORBITALIS 13. ATTACHMENTS AND NERVE SUPPLY OF EXTRA OCULAR MUSCLES 1.LEVETOR PALPEBRAE SUPERIORIS: ORGIN:arises from the orbital surface of the lesser wing of sphenoid bone just anterosuperior to the optic canal and to the origin of the superior rectus. INSERTION: tarsal plate and skin of upper eyelid. NERVE SUPPLY: oculomotor nerve(upper division). 14. 2.SUPERIOR RECTUS: ORIGIN:upper margin of the common tendinous ring. INSERTION:sclera;7.7mm behind the limbus /cranioscleral junction NERVE SUPPLY: oculomotor nerve(upper division). 3.INFERIOR RECTUS: ORIGIN: lower margin of the common tendinous ring. INSERTION:sclera;6.5mm behind the limbus/cranioscleral junction. NERVE SUPPLY: oculomotor nerve(lower division) 15. 4.MEDIAL RECTUS: ORGIN: medial margin of the common tendinous ring. INSERTION:sclera;5.5mm behind the limbus /cranioscleral junction. NERVE SUPPLY: oculomotor nerve(lower division) 5.LATERAL RECTUS: ORGIN: lateral margin of common tendinous ring. INSERTION: sclera;6.9mm behind the limbus/cranioscleral junction. NERVE SUPPLY: abducent nerve 16. 6.SUPERIOR OBLIQUE: ORGIN:roof of the orbit immediately in front of the upper and medial parts of optic foramen. INSERTION:sclera;midway between the entrance of the optic nerve and cornea. NERVE SUPPLY:trochlear nerve. 7.INFERIOR OBLIQUE: ORGIN:orbital surface of maxilla, lateral to nasolacrimal groove. INSERTION:sclera;lateral part under cover of the lateral rectus muscle. NERVE SUPPLY:oculomotor nerve(lower division) 17. INSERTION OF EXTRA OCULAR MUSCLES 18. ACTIONS OF EXTRA OCULAR MUSCLES 1.superior rectus: adduction, elevation, intorsion(medial rotation). 2.inferior rectus: adduction. depression, extorsion(lateral rotation). 3.medial rectus: adduction 4.lateral rectus:abduction 5.superior oblique: abduction, depression, intorsion. 6.inferior oblique: abduction, elevation, extorsion. 19. ARTERIAL SUPPLY OF ORBIT OPHTHALMIC ARTERY[Main trunk] CENTRAL ARTERY OF RETINA LACRIMAL ARTERY 20. VESSELS OF THE ORBIT: 1.OPHTHALMIC ARTERY: it is a branch of the cerebral part of internal carotid artery, given off medial to anterior clinoid process close to optic canal. COURSE AND RELATIONS: 21. it terminates near the medial angle of the eye by dividing into SUPRATROCHLEAR DORSAL NASAL 22. BRANCHES 23. BRANCHES: 1.within the dural sheath:central artery of retina 2.After piercing the duramater:lacrimal branch(runs along the lateral wall of the orbit). 3.Main trunk 24. 3.Main trunk gives off: a)posterior ciliary artery b)supraorbital and supratrochlear c)anterior and posterior ethmoidal arteries d)medial palpebral branches supply the eyelids e)the dorsal nasal branch supplies the upper part of nose 25. 2,CENTRAL ARTERY OF RETINA: first and most important branch of ophthalmic artery, This is an end artery 26. 3.LACRIMAL ARTERY BRANCHES:1.branches to lacrimal gland. 2.two zygomatic branches. 3.lateral palpebral branches supplies eyelid 4.recurrent meningeal branch(enters into middle cranial fossa through superior orbital fissure). 5.muscular branches supply the muscles of the orbit. 27. VENOUS DRAINAGE: OPHTHALMIC VEINS are of two types a)superior ophthalmic vein b)inferior ophthalmic vein 28. LYMPHATICS OF THE ORBIT: the lymphatics drain into the preauricular lymph nodes. NERVES SUPPLY OF THE ORBIT: 1. OPTIC NERVE 2. OCULOMOTOR NERVE WITH CILIARY GANGLION. 3. TROCHLEAR 4. BRANCHES OF OPHTHALMIC AND MAXILLARY NERVES 5. ABDUCENT NERVES 6. SYMPTHETIC NERVES. 29. 1.OPTIC NERVE it is the nerve of sight. 30. RELATIONS OF OPTIC NERVE IN THE ORBIT 1.At the apex of the orbit: nerve is closely surrounded by recti muscles,ciliary ganglion lies between the optic nerve and lateral rectus. 2.The central artery of retina and vein pierces the nerve inferomedially about 1.25cm behind the eyeball. 31. 3.Optic nerve is crossed by: superiorly:ophthalmic artery,nasociliary nerve and superior ophthalmic vein inferiorly: nerve to medial rectus 4.Near the eyeball, the nerve is surrounded by fat containing the ciliary vessels and nerves 32. 2.CILIARY GANGLION: Peripheral parasympathetic ganglion placed in the course of oculomotor nerve. It has motor,sensory,and parasympathetic fibers 33. MOTOR ROOT supplies sphincter pupillae and ciliaris muscle SENSORY ROOT - contains sensory fibers for the eyeball SYMPATHETIC ROOT supplies blood vessels of the eyeball and dialator pupillae 34. OPHTHALMIC NERVE 35. 3.LACRIMAL NERVE: SUPPLY: a)lacrimal gland,conjunctiva,upper eyelid b)its own fibers to the gland are sensory. c)the secretomotor fibers to the gland come from the greater petrosal nerve through its communication with zygomaticotemporal nerve 36. 4.FRONTAL NERVE: Supratrochlear supplies: conjuctiva,the upper eyelid, a small area of the skin of the forehead above the nose. Supraorbital supplies:conjuntiva,central part of the upper eyelid, frontal air sinus and the skin of the forehead and the scalp up to the vertex(up to the lambdoid suture) 37. 5.NASOCILIARY NERVE: BRANCHES: a)A communicating branch to the ciliary ganglion forms the sensory root of the ganglion. It is often mixed with sympathetic root. b)Two or three long ciliary nerves c)The posterior ethmoidal nerve d)The infratrochlear nerve is the smallest terminal branch of the nasociliary nerve. 38. It SUPPLIES: conjunctiva, the lacrimal sac, and the caruncle,the medial ends of the eyelids and the upper half of the external nose. e)Anterior ethmoidal nerve: largest terminal branch of the nasociliary nerve. 39. 6.INFRAORBITAL NERVE: BRANCHES: 1)Anterior superior alveolar nerve 2)Middle superior alveolar nerve 3)Terminal branches 7.ZYGOMATIC NERVE: BRANCHES: Zygomatico temporal Zygomatico facial 40. 8.SYMPATHETIC NERVES OF THE ORBIT: arises from the internal carotid plexus 9.ABDUCENT NERVE : supplies LATERAL RECTUS MUSCLE 10.TROCHLEAR NERVE : supplies SUPERIOR OBLIQUE MUSCLE 41. CLINICAL ANATOMY 1)Weakness or paralysis of a muscle causes squint or strabismus, which may be concomitant Or paralytic. concomitant squint paralytic squint 42. 2) Nystagmus : characterized by involuntary,rythmical oscillatory movements of the eye. It is due to the incordination of the ocular muscles. may be either vestibular,cerebellar and congenital. 43. 3)Central artery of retina is the only arterial supply to most of the nervous layer, the retina of the eye. if this artery is blocked there is sudden blindness. 44. 4)Optic neuritis:- Characterized by pain in and behind the eye on ocular movements and on pressure. it is the inflammation of the optic nerve may cause complete/partial loss of vision. 45. 5)TELECANTHUS:-Refers to as increased distance between the medial canthus of the eyes(intercanthal distance), while inter-puppillary distance is normal. 46. 6)HYPERTELORISM:-refers to increased inter- pupillary distance. it is a symptom of various syndromes. EDWARDS SYNDROME APERT SYNDROME 47. a)The supraperiosteal space : potential space between the bone and the periosteum. b)Peripheral space:-it is bounded peripherally by the periorbita and internally by four recti 7)Optic atrophy:- caused by a variety of diseases. it may be primary or secondary. 6)Surgical spaces in the orbit:- 48. c)Central space : also called retro bulbar space, bounded anteriorly by the tenons capsule Lining back of the eyeball and peripherally by 4 recti muscles. d)Tenons space : potential space around the eyeball between the sclera and tenons capsule. 49. 9)RETROBULBAR HEAMORRHAGE may results in temporary blindness or Diminished vision. 50. 11)FRACTURES OF ZYGOMATIC COMPLEX:-fractures in the region of zygomatico-temporal suture and zygomaticomaxillary suture; it may result in diplopia , proptosis, circumorbital ecchymosis, subconjunctival hemorrhage. 51. 10)ENOPHTHALMOS:-means inward sinking of the eye 52. 12)DIPLOPIA:-blurred double vision experienced by the patient. There are two types of diplopia -MONOCULAR DIPLOPIA and BINOCULAR DIPLOPIA. 53. HESS CHART 54. SNELLENS CHART A Snellen chart is an eye chart used by eye care professionals and others to measure visual acuity. Snellen charts are named after the Dutch ophthalmologist Herman Snellen who developed the chart in 1862.[1] Vision scientists now use a variation of this chart, designed by Ian Bailey and Jan Lovie . "20/20" (or "6/6") vision 55. 13) BLOWOUT FRACTURE:- A severe blow to the orbit may cause the contents of the orbital cavity to explode downward through the floor of the orbit into the maxillary sinus. 14)BLOW IN FRACTURE :- is an inwardly displaced fracture of orbital rim or wall resulting in decreased orbital volume. Findings: proptosis, globe rupture , superior orbital syndrome, orbital nerve injury. 56. 15) ORBITAL INFECTIONS 16) COMPLETE & PARALYSIS OF THIRD CRANIAL NERVE- Webers syndrome 17) TROCHLEAR NERVE DAMAGE 18) PARALYSIS OF ABDUCENT NERVE 57. 19) SUPERIOR ORBITAL FISSURE SYNDROME -Rochon Duvingneuds Syndrome - Orbital Apex Syndrome 20)EXOPHTHALMOS / EYE PROPTOSIS -Eye dislocation/ eye luxation - Pulsating exophthalmos - Erdheim Chester disease - Graves disease 58. PTOSIS 59. GLAUCOMA CATARACTS 60. EYE GOUGING Eye-gouging is the act of pressing or tearing the eye using the fingers or instruments. Eye-gouging involves a very high risk of eye injury, such as eye loss or blindness. 61. REFERENCE B D Chaurasias Human Anatomy For Dental Students Volume 3,fifth Edition Essentials Of Anatomy For Dentistry Students -D.R.Singh Handbook Of Osteology S. Poddar ; Ajay Bhagath ;Twelfth Edition Grays Anatomy For Students Textbook Of Oral And Maxillofaacial Surgery S M Balaji Human Anatomy: Head, Neck And Brain By A. Halim