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Orbit and eye,


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Orbit and eye,

  2. 2. “I am a camera with its shutter open, quite passive, recording, not thinking.” The human eye blinks an average of 12 times a min / 4,200,000 times a year. All babies are colour blind when they are born and do not produce tears until the baby is approximately six to eight weeks old. People generally read 25% slower from a computer screen compared to paper. It's impossible to sneeze with your eyes open. INTRODUCTION
  4. 4. DEVELOPMENT  The eye develops from several types of tissues. i. Retina & RPE – Neural Ectoderm ii. Lens – Surface Ectoderm iii. Sclera & Anterior Chamber – Migrating Cells.  Optic Vesicle  Lens Placode  Mesenchyme  Visceral Mesoderm Mutations in the SHH gene or inhibition of protein processing results in cyclopia. The phenotype results in a single eye in the center of the face. DEVELOPMENT
  5. 5. OPTIC VESICLE oThe primary optic vesicles arise as an evagination of neural tube epithelium. oThe optic vesicle is connected to the procencephalon by the optic stalk, which will become the optic nerve. oIn humans, eye development isn’t completed until several months after birth. DEVELOPMENT
  6. 6. •The lens placode is induced by contact between the optic vesicle and the overlying ectoderm. •The optic vesicle infolds, forming a bilayered optic cup. The inner wall of the optic cup becomes the neural retina, while the outer wall becomes the pigment epithelium •The lens placode then invaginates and pinches off to form a hollow lens and is subsequently filled with differentiating primary fiber cells that elongate from the LENS PLACODEDEVELOPMENT
  7. 7. •The surface ectoderm from which the lens vesicle forms gives rise to the cornea. •The iris and ciliary body develop at the periphery of the retina. •Unlike the other muscles of the body, part of the iris is derived from the ectodermal layer. •Migrating mesenchymal tissues form the sclera, trabecular meshwork, and anterior chamber. DEVELOPMENT
  8. 8. DEVELOPMENT  At birth, the eye is relatively large in relation to the rest of the body.  The eye reaches full size by the age of 8 years.  The lens continues to enlarge throughout the life.  The iris has a bluish color due to little or no pigment on the anterior surface.  During early infant life, the cornea & sclera can be stretched by raised IOP → enlargement of the eye. DEVELOPMENT
  10. 10. ORBITORBIT  Orbit / eye socket is roughly irregular four sided pyramid located on either side of root of nose.  Base - at the orbital opening  Apex - at optical canal  Axis directed posteriorly and medially  Medial walls - nearly parallel  Medial and lateral walls makes an angle of 45 25mm
  11. 11. ORBITAL CAVITY CONTRIBUTED BY 7 BONES  Frontal bone  Zygomatic bone  Maxilla  Ethmoid bone  Sphenoid bone  Lacrimal bone  Palatine bone ENTRANCE OF THE ORBIT  Frontal, Zygomatic, Maxillary Bones ORBIT ORBIT
  12. 12. ROOF  Orbital plate of frontal bone  Posteriorly small portion contributed by lesser wing of sphenoid.  Anteriomedially frontal sinus is present in the frontal bone.  Supra orbital foramen is present at junction of medial and middle half. ORBIT
  13. 13. FLOOR  Orbital plate of maxilla  Anteriolaterally- zygomatic bone  Posteriomedially- orbital process of palatine bone  On the lateral side, anteriorly continues with the lateral wall but separated posteriorly by inferior orbital fissure.  It roofs maxillary sinus  Its thin and is most commonly fractured. ORBIT
  14. 14. MEDIAL WALL  Orbital plate of ethmoid bone (lamina papyracia)  Anteriorly – lacrimal bone  At the apex – body of sphenoid  Lacrimal bone contains fossa for nasolacrimal sac ORBIT
  15. 15. L ATERAL WALL  Frontal process of zygomatic bone anteriorly and the orbital surface of greater wing of sphenoid posteriorly.  Thickest wall of the orbit  Orbital tubercle – lateral palpebral ligament  Continuous with roof anteriorly and separated posteriorly by superior orbital fissure ORBIT
  16. 16. COMMUNICATIONSORBITALCAVITY OPTIC CANAL  Located between two roots that connect lesser wing of sphenoid with body of sphenoid  Connects orbit and middle cranial fossa  Transmits optic nerve, menengial sheaths, opthalmic artery
  17. 17. COMMUNICATIONSORBITALCAVITY SUPERIOR ORBITAL FISSURE  Gap between greater and lesser wings of sphenoid  Connects orbit and cranial cavity  Transmits occulomotor, trochlear, opthalmic, abduscens nerves and opthalmic veins
  18. 18. COMMUNICATIONSORBITALCAVITY INFERIOR ORBITAL FISSURE  Bounded by Above – greater wing of sphenoid Below – maxilla Laterally – zygomatic bone  Connects orbit with pterigopalatine and infratemporal fossa  Transmits infraorbital, zygomatic branches of maxillary nerve and vessels, orbital rami of pterigopalatine ganglion
  19. 19. COMMUNICATIONSORBITALCAVITY  ETHMOIDAL FORAMEN  At the junction of frontal and ethmoid bones, anteriorly and posteriorly  Connects with ethmoid sinuses, anterior cranial fossa, nasal cavity.  Openings for Zygomatico temporal and zygomatico facial nerves  In the lateral wall on zygomatic surface
  20. 20. CONTENTS ORBITALCAVITY  Eye ball occupying 1/5th of the orbit  Extra ocular muscles  Optic, Occulomotor, Trochlear, Abduscens, Opthalmic and Maxillary nerves  Ciliary parasympathetic ganglion  Opthalmic vessels  Nasolacrimal apparatus  Orbital fat and connective tissue
  21. 21. EYEBALL
  22. 22. EYE BALLEYEBALL Spherical with 2.3 cms in diameter Outer coat – 2 spheres of different radii Anterior segment – smaller sphere, transparent cornea Posterior segment – larger sphere, opaque sclera Middle / vascular coat – Choroid, Ciliary body, Iris Inner / nervous coat – Retina
  23. 23. Cornea and sclera are continuous, but have different morphology & function EYEBALL
  24. 24. EYEBALL
  25. 25. EYEBALL
  26. 26. EYEBALL
  27. 27. CONJUNCTIVA  Mucous membrane with non keratinized squamous epithelium and globlet cells.  Extends from limbus to cover interior eyelids.  Thin, richly vascularized substantia propria  Can be divided into three geographic zones: ◦ Palpebral ◦ Forniceal ◦ Bulbar EYEBALL
  28. 28. CORNEA • The cornea occupies the center of the anterior pole of the globe. • It measures 12 mm horizontally & about 11 vertically. • The cornea is transparent and highly innervated. • It is avascular, gets O2 & nutrients from aqueous humor and outside surface. • Kept moist by tears. • Responsible for most of the eye’s ability to refract and focus light EYEBALL
  29. 29. SCLERAEYEBALL • The sclera covers the posterior four fifths of the surface of the globe, with an anterior opening for the cornea and a posterior opening for the optic nerve • Composed of dense fibrous connective tissue, almost avascular • Maintains shape of the eyeball • Anteriorly – Corneoscleral junction – limbus • Posteriorly – fused with dural sheath of optic nerve • Externally covered by bulbar conjunctiva • Internally attached to choroid by suprachoroid lamina • Provides protection to delicate structures, • Serves as an attachment for the extraocular muscles
  30. 30. CHOROID  The choroid, the posterior portion of the uveal tract, nourishes the outer portion of the retina. It averages 0.25 mm in thickness and consists of three layers of vessels:  The choriocapillaris, the innermost layer  A middle layer of small vessels  An outer layer of large vessels EYEBALL
  31. 31. IRIS EYEBALL • Colored structure surrounding the pupil. • Controls amount of light entering the eye • Controls the size of the pupil through the sphincter pupillae (shrinks pupil) and a diffuse dilator pupillae (enlarges pupil) • Spongy stroma with melanocytes: faces anterior chamber • Pigmented epithelium faces posterior chamber. This epithelium becomes the ciliary body laterally. • When it is full open, it is about f/2 and f/3. This happens at
  32. 32. CILIARY BODY  Triangular in cross section.  The apex of the ciliary body is directed posteriorly toward the ora serrata.  Base gives rise to the iris.  The ciliary body has three principal functions: ◦ aqueous humor formation: low-protein plasma- like substance made continuously by the epithelium of ciliary body. Nourishes cornea, lens, iris, corneal endothelium, & stroma. Secreted into posterior chamber, flows around iris through pupil to “the angle” ◦ It also plays a role in the trabecular and uveoscleral outflow of aqueous humor ◦ Accommodation EYEBALL
  33. 33. LENS  The lens is a biconvex structure located directly behind the posterior chamber and pupil  Diameter of about 9-10 mm & width of about 6 mm.  lens fibers: extremely long cells with no nuclei, stretch anterior to posterior. Cytoplasm filled with crystallin, arranged in a regular lattice  Lens capsule: thick basement membrane surrounding lens. Attachment site for the zonules.  The lens has certain unusual features. It lacks innervation and is avascular. Transparent because of anucleate nature and fibers containing crystalline proteins. EYEBALL
  34. 34. RETINA  Photoreceptors: contain photopigment in discs located within outermost segment. When light interacts with the photo pigment, conformational change and neural signal  Blood supply: central retinal artery enters through optic disk and ramifies in the inner surface of retina  Capillary network of the choroid, the choroicapillaris supplies photoreceptors through Bruch’s membrane and the RPE  2 types of photoreceptors: ◦ Rods: sensitive in dim light, not wavelength sensitive ◦ Cones: sensitive in bright light, differential sensitivity to wavelength. Three kinds of cones are - red, green, and blue. These cones work together to help us see millions of colors. EYEBALL
  35. 35. CHAMBERSEYEBALL Iris and lens separate eye into three chambers Vitreous chamber : largest chamber, posterior to lens, filled with gel like vitreous humour Anterior chamber : between cornea and iris Posterior chamber : between iris and lens Both are filled with aqueous humour, which provides nourishment to avascular lens and cornea
  36. 36. VITREOUS  The vitreous cavity occupies four fifths of the volume of the globe  Important to the metabolism of the intraocular tissues because it provides a route for metabolites used by the lens, ciliary body and retina  serves as a medium to maintain the path of light between the lens and the retina  free from diffusing and absorbing elements  Its volume is close to 4.0 ml  Although it has a gel-like structure, the vitreous is 99% water  Its viscosity is approximately twice that of water, mainly because of the presence of the mucopolysaccharide, hyaluronic acid. EYEBALL
  37. 37. ACCOMMODATION  The lens changes shape to focus light on the back of the eye regardless of the distance of the object  Cornea curvature is fixed, so focus comes from changes in the lens curvature through the ciliary muscles  Lens with no tension: would be curved/round  normal state of lens: flattened by the tension of the zonules/suspensatory ligaments.  To curve lens: ciliary muscles contract and ciliary body moves closer to the lens. Zonules go slack.  To flatten the lens: ciliary muscles relax, ciliary body moves away from the lens. Stretches the zonules. EYEBALL
  38. 38. Myopia (Near-sightedness)  This person can see close objects clearly, but has trouble seeing distant objects.  Usually occurs because the distance between the lens and the retina is too large or because the cornea-lens combination converges light too strongly.  Light from distant objects is brought into focus in front of the retina. MYOPIA
  39. 39. Hyperopia (Far-sightedness) • This person had no problem seeing objects in the distance, but has trouble seeing nearby objects. • The eye cannot refract light well enough to form an image on the retina. • Usually occurs because the distance between the lens and the retina is too small or because the cornea-lens combination is too weak. Light from nearby objects focuses behind the retina. HYPEROPIA
  40. 40.  Even within the cone and rod system, your retina adjusts its sensitivity in response to the overall light level  When you walk into a dark room, you can’t see anything, but after a few minutes, you adapt and can start to see things and vice- versa.  Dark adaptation is a slow process, but allows us to see in a huge range of light levels DARKADAPTION CLINICAL CORRELATIONS
  41. 41. CLINICAL TERMS  Glaucoma: Elevated intraocular pressure from overproduction of aqueous humor or blockage in drainage. High pressure in the anterior chamber transduced through vitreous body, pressure on retina. Can damage neural retina by impeding blood flow in reitinal arterioles. ◦ Open angle glaucoma: increased production ◦ Closed angle glaucoma: iris closes the angle, blocking drainage  Cataract: Clouding of the crystalline lens of the eye.In a normal eye, the crystalline lens is almost transparent, however injury, age or disease can cause the lens to eventually lose its clarity. CLINICALTERMS
  42. 42. CLINICAL TERMSCLINICALTERMS  Hemianopia: Blindness in one-half of the visual field  Amblyopia: (lazy eye) Decreased vision in one eye that leads to the use of the other eye as the dominant eye. A problem most commonly associated with children.  Presbyopia: Progressive loss of vision which begins in mid-life. Near vision becomes blurry, making reading glasses necessary. Over time, the blurriness extends to intermediate vision, making computer glasses useful. Bifocals are worn to improve near vision and distance vision if necessary. • Diplopia (double vision) The perception of two images of a single object.
  43. 43. CLINICAL TERMSCLINICALTERMS  Strabismus: (Misaligned eyes / crossed eye) Condition is the lack of coordination between the eyes, one eye turns out, down, or up while the other looks straight ahead.  Nystagmus: Rapid and uncontrollable eye movements. an involuntary, constant, rhythmic movement of the eyeball that can be congenital or caused by a neurological injury or drug use  Anisocoria A condition in which the pupils are unequal in size. this condition can be congenital or caused by a head injury, aneurysm or pathology of the central nervous system
  44. 44. CLINICAL TERMSCLINICALTERMS • Chalazion : A slowly developing lump that forms due to blockage and swelling of an oil gland in the eyelid. • papilledema (chocked disk) swelling and inflammation of the optic nerve at the point of entrance into the eye through the optic disk. this swelling is caused by increased intracranial pressure and can be due to a tumor pressing on the optic nerve • Scotoma (blind spot) An abnormal area of absent or depressed vision surrounded by an area of normal vision • Bitot spots : Raised, silvery white, foamy, triangular
  45. 45. CLINICAL TERMSCLINICALTERMS  Astigmatism: An eye condition where the eye cannot focus light uniformly in all directions resulting from an irregular curvature. Astigmatism results in mild to moderately blurred vision and/or eyestrain.  Floaters and Spots: A generalized term used to describe small specks moving subtly but noticeably in your field of vision. A floater or a spot is likely a tiny clump of gel or cells in the vitreous. Aging, eye injury and breakdown of the vitreous are the main causes of floaters and spots. • Subconjunctival hemorrhage Bleeding between the conjunctiva and the sclera.
  46. 46. CLINICAL TERMSCLINICALTERMS  Pterygium: A raised growth on the eye that is most often directly related to over-exposure to the sun. Dry, dusty conditions may also contribute to development of these growths. Protecting your eyes from UV radiation is a critical preventive measure.  Blepharitis: Inflammation of the eyelids. It can have a variety of causes, such as an allergic reaction, bacterial infection, or excess oil produced by eyelid glands.  Dacroadenitis An inflammation of the lacrimal gland that can be caused by a bacterial, viral or fungal infection. signs and symptoms include the sudden severe pain, redness and pressure in the orbit of the eye  Keratoconus: An inherited corneal disease. The cornea gradually becomes thinner and less able to maintain its shape against the pressure of the fluids inside the eye.
  47. 47. VISUAL PATHWAY Retina Optic nerve Optic chiasm Optic tract Lateral geniculate body optic radiation occipital lobe optical center
  49. 49. Oculocardiac Reflex  Stimulated by:  Increased pressure on the globe  Traction of extrinisic eye muscles  Ocular regional anesthesia techniques  Results in:  Cardiac Arrhythmias  Bradycardia  Asystole ( and severe increased sphincter tone for the anesthetist)
  50. 50. Oculocardiac Reflex  Stimulation causes to activation of an Afferent Arc via CN V, trigeminal.  Efferent Arc via CN X, vagus.  Treatment:  STOP STIMULATION!  Verify adequate ventilation & oxygenation  Atropine IVP .01-.02mg/kg (pretx does not always prevent reflex)  May also need local anesthetic infiltration  Via retrobulbular block or peribulbar block.  Severe Cases: May need to perform CPR.
  51. 51. Oculocardiac Reflex  Reflex usually subsides with repeated stimulation  More common in strabismus surgery with pediatric pts.  Can occur in all age groups.  Be vigilant, be prepared.
  53. 53. EYELIDEYELID An eyelid is a thin fold of skin that covers and protects an eye.
  54. 54. THE LID MARGIN  When eye is open, the upper lid covers about 1/6th of the cornea & the lower lid just touches the limbus.  It is About 2mm broad and is divided into two parts by punctum.  The medial, lacrimal portion is rounded and devoid of lashes or glands.  The lateral, ciliary portion consist of rounded anterior border, a sharp posterior border and an inter-marginal strip.  The medial canthus is about 2mm higher than the lateral canthus
  55. 55. LAYERS OF EYE LIDEYELID Anterior (cutaneous) to posterior (conjunctiva)  Skin  Subcutaneous tissue.  Striated muscle (orbicularis).  Submuscular areolar tissue.  Orbital fat  Fibrous layer with tarsal plates.  Mucous membrane or Conjunctiva.
  56. 56. 1.SKIN: It is elastic having fine texture and is the thinnest of the body. 2.THE SUBCUTANEOUS AREOLAR TISSUE: It is very loose and contain no fat. It is thus readily distended by oedema or blood. 3.THE LAYER OF STRIATED MUSCLE:- It consist of orbicularis muscle which comprises three portions:- i.The orbital ii.The palpebral iii.The lacrimal It closes the eyelids & is supplied by zygomatic branch of the facial nerve.
  57. 57. 4. SUBMUSCULAR AREOLAR TISSUE: The layer of loose connective tissue.  The nerve and vessels lie in this layer.  Therefore, to anaesthetize lid, injection is given in this plane. 5.FIBROUS LAYER:-consists of central tarsal plate and peripheral septum orbitale. a.) Tarsal plate: There are two plates of dense connective tissue, which give shape and firmness to the lids. Both join with each other at medial and lateral canthi and attached to the orbital margins through medial and lateral palperable ligaments
  58. 58. b.) Septum orbitale It is thin membrane of connective tissue perforated by nerves , vessels and LPS muscle, which enter the lids from the orbit. 6. LAYER OF NON-STRIATED MUSCLE FIBRES: It consist of the palpebral muscle of muller which lies deep to the septum orbitale in both the lids. In the upper lid it arises from the fibres of LPS muscle and in the lower lid from prolongation of the inferior rectus muscle; and is inserted on the peripheral margins of the tarsal plate. It is supplied by sympathetic fibres.
  59. 59. NERVES OF LIDS  Motor supply Facial - supplies orbicularis muscle, Oculomotor - supplies LPS muscle Sympathetic fibres - supply the muller’s muscle.  Sensory supply From branches of the trigeminal nerve.
  60. 60. MUSCLES
  61. 61. MUSCLESEYEMUSCLES  Extra-ocular muscles 1. Recti muscles 2. Oblique muscles 3. Levator palpebrea superioris  Intra-ocular muscles 1. Sphinter pupillae 2. Dilator pupillae
  62. 62. RECTI MUSCLES  Four in number, approximately strap shaped  Attached to common tendinous ring  Each rectus passes forwards and attached to tendinous expansion into the sclera EYEMUSCLES
  63. 63. MUSCLE ACTION Superior rectus Upwards and medially Inferior rectus Downards and medially Medial rectus Medial movement ( adduction ) Lateral rectus Lateral movement ( abduction ) EYEMUSCLES
  64. 64. OBLIQUES  SUPERIOR OBLIQUE  Fusiform muscle  Arises from body of sphenoid, passes through trochlear fossa of frontal bone, attached to sclera between superior and lateral recti muscles  Moves the eye laterally and intrudes the eyeball EYEMUSCLES
  65. 65. OBLIQUES  INFERIOR OBLIQUE  Lies near anterior margin of floor of orbit  Inserted into the lateral part of the sclera behind the equator of eyeball  Moves eye laterally and causes extorsion EYEMUSCLES
  66. 66. LEVATOR PALPEBRAE SUPERIORIS • Thin triangular muscle • Arises from inferior aspect of lesser wing of sphenoid • Ends in wide aponeurosis, some fibers attaches to anterior end of tarsal plate and others to the skin of eyelid • Laterally passes between orbital and palpebral parts of lacrimal gland and attached to the orbital tubercle • Medially continues as loose connective tissue on medial palpebral ligament • Innervated by occulomotor nerve • Elevates upper eyelid • Linked to superior rectus by check ligament, thus upper eyelid elevates when eye directed upwards EYEMUSCLES
  67. 67. Intrinsic Eye MusclesEYEMUSCLES
  69. 69. ARTERIAL SYSTEM Internal carotid artery Ophthalmic artery Central retinal A Short post ciliary A Long post ciliary A Anterior ciliary A Lacrimal A Superior muscular A Inferior muscular A Posterior ethmoidal A Anterior ethmoidal A Supraorbital A Supratrochlear A BLOODSUPPLY
  70. 70. 9lllllllllllllllllllllllllllBLOODSUPPLY
  71. 71. Venous system Central retinal V Superior vortex V Superior episcleral plexus Inferior vortex V Inferior episcleral plexus Pterygoid plexus Superior ophthalmic V Cavernous sinus Jugular v BLOODSUPPLY
  74. 74. NERVE SUPPLY
  76. 76. Cranial Nerve III (Occulomotor) • It supplies all the extraocular muscles except the superior oblique and the lateral rectus • It also carries cholinergic innervation to the pupillary sphincter and the ciliary muscle • The CN III nucleus consists of several distinct, large motor cell subnuclei, each of which subserves the extraocular muscle it innervates • The Edinger-Westphal nucleus provides the parasympathetic preganglionic efferent innervation to the ciliary muscle and pupillary sphincter NERVESUPPLY
  77. 77. Cranial Nerve III  CN III usually divides into superior and inferior divisions  The superior division of CN III innervates the superior rectus and levator palpebrae muscles.  The larger inferior division splits into three branches to supply the medial and inferior rectus muscles and the inferior oblique.  The parasympathetic fibers enter the inferior division, and course through the branch that supplies the inferior oblique muscle and join the ciliary ganglion.  They synapse with the postganglionic fibers, which emerge as many short ciliary nerves. NERVESUPPLY
  78. 78. Cranial Nerve IV (Trochlear)  Cranial nerve IV has the longest intracranial course  The CN IV the only cranial nerve that is completely decussated and the only motor nerve to exit dorsally from the nervous system.  CN IV enters the orbit through the superior orbital fissure outside the annulus of Zinn and runs superiorly to innervate the superior oblique muscle NERVESUPPLY
  79. 79. Cranial Nerve V (Trigeminal)  The largest cranial nerve  Possesses both sensory and motor divisions The sensory portion subserves the greater part of the scalp, forehead, face, eyelids, eye, lacrimal gland, extraocular muscles, ear, dura mater, and tongue  The motor portion innervates the muscles of mastication through branches of the mandibular division NERVESUPPLY
  80. 80. Divisions of Cranial Nerve V  Ophthalmic ◦ Frontal ◦ Lacrimal ◦ Nasociliary  Maxillary  Mandibular NERVESUPPLY
  81. 81. Cranial Nerve VI (Abducens)  The nucleus of cranial nerve VI is situated in the floor of the fourth ventricle, beneath the facial colliculus, in the caudal pons  CN VI runs below and lateral to the carotid artery and may transiently carry sympathetic fibers from the carotid plexus  It passes through the superior orbital fissure within the annulus of Zinn and innervates the lateral rectus muscle on its ocular surface NERVESUPPLY
  82. 82. CILIARYGANGLION CILIARY GANGLION  Para sympathetic ganglion which is a small, flat, reddish grey swelling 1-2 mm diameter, located near the apex of orbit medial to superior orbital fissure.  Three types of nerve fibers run through the ganglion:  1. parasympathetic fibers 2.sympathetic fibers 3.sensory fibers  Only parasympathetic fibers form synapses in the ganglion and other two types of nerve fibers simply pass through.
  83. 83. CONNECTIONS Ciliary nerve innervates two muscles 1.Sphincter pupillae: constricts the pupil, a movement known as Miosis. 2.Ciliaris muscle: Releasing tension on the , making the lens more convex, also known as accommodation CILIARYGANGLION
  85. 85. Orbital Fat  Contains two compartments:  Central compartment (retrobulbar & intracone)  Peripheral compartment (peribulbar & pericone) The importance of the orbital fat, is that it contains the motor & sensory nerves for the eye. Therefore regional anesthesia can be injected into the fat and provide the patient with an effective block.
  87. 87. LACRIMAL APPARATUS LACRIMALAPARATUS  Lacrimal glands  Excretory ducts  Lacrimal punctum  Lacrimal canals  Lacrimal sac  Naso lacrimal duct
  88. 88. Lacrimal gland - orbital part - palpebral part Separated by levator palpebrae superioris and are continuous posteriosuperiorly LACRIMALAPARATUS
  90. 90. Nerve supply LACRIMALAPARATUS
  92. 92. TRAUMA
  93. 93. Basic First-Aid Techniques ◦ Specks in the eye  Do not rub the eye  Flush the eye with a large amount of water  See a doctor if the speck does not wash out, or if pain or redness continues ◦ Cuts, punctures, or objects stuck in the eye  Do not wash out the eye  Do not try to remove an object stuck in the eye  See a doctor at once
  94. 94. First-Aid Techniques ◦ Chemical burns  Flush the eye immediately with water or any drinkable liquid and continue flushing for at least 15 minutes. For caustic or basic solutions, continue flushing while on the way to the doctor.  Flush the eye even if it has a contact lens. Flushing over the lens may dislodge it. ◦ Blows to the eye  Apply a cold compress without pressure.  Tape a plastic bag containing crushed ice to the forehead and let it rest gently on the injured eye.  See a doctor at once in cases of continued pain, reduced vision, blood in the eye, or discoloration,
  95. 95. MAKE EYE SAFETY •BLOOD SPLASH INJURY •Disposable surgical masks with full-face visors have been shown to offer the highest level of protection from blood splash injury •The use of masks and visors should be standard practice for all theatre staff, including assistants, scrub nurses and observers. •If such an incident occur, a procedure similar to that used for needle-stick injury may be followed. •The eye should first be rinsed thoroughly to remove as much of the fluid as possible. •Serology should be ordered promptly to obtain a baseline for future comparisons. •Hiv screen and acute hepatitis screen are indicated. •Post-exposure prophylaxis (pep) should be initiated as soon as practicable unless the patient is known to be HIV, HBV and HCV negative.
  97. 97. OPHTHALMIC ASSESSMENT OPHTHALMICASSESSMENT  Ophthalmic assessment is mandatory for every patient who has sustained mid facial trauma severe enough to cause a fracture.  HISTORY - Time, place, nature of injury - whether glasses were worn at the time of injury - antecedent visual status - whether any squit or other abnormalities present before the injury
  98. 98. VISUAL ACUITY OPHTHALMICASSESSMENT • Measure of resolving power of the eye • Recorded as a fraction distance of the patient from the chart line he / she sees at that distance PRINCIPLE : Two distinct points appear as separate only when they subtend an angle of 1 minute at nodal plane of the eye. Each test letter is designed as it subtends an angle of 5 minutes at nodal plane of eye.
  99. 99. VISUAL ACUITYOPHTHALMICASSESSMENT • SNELLEN’S CHART • Patient at 6 mts from snellen’s chart. • Test letters are constructed so that edges subtend a visual angle of 1min of arc. • For normal eye with 6/6 vision, each complete test letter subtends 5 min of arc at the eye. • If patient cant read at 6/6 and doesn’t have glasses before, patient is asked to see through pin hole. If acuity increases
  100. 100. VISUAL ACUITY OPHTHALMICASSESSMENT  When visual acuity is less and patient cant read , then measured by counting fingers.(CF)  If acuity is still less, then hand movements are recorded.(HM)  For patients with polytrauma acuity for near vision can be measured as snellens letters subtends same angle at 0.33 mts.
  101. 101. VISUAL FIELDS OPHTHALMICASSESSMENT  Assessed in patients with sustained severe head trauma  CENTRAL VISUAL FUNCTION  Patient is asked to look at red object and x-ray illuminator with each eye separately and compare the color and brightness perceived respectively.  Color desaturation – traumatic optic neuropathy  Decreased brightness – optic nerve damage  Patient is told to look at the examiners nose with each eye separately and asked whether any part of face is missing or blurred. This detects paracentral scotoma (choroidal tear)
  102. 102. VISUAL FIELDSOPHTHALMICASSESSMENT  BINOCULAR VISUAL FIELD TESTING  Examiner sits opposite to patient at 1mt looking into his eyes.  Hands were placed in outer quadrants and asked to identify the finger movements.  Patients suspected of left homonymous hemianopia when left field of vision is defecit.  CENTRAL VISUAL FIELD TO CONFRONTATION  Traumatic damage to visual pathways is more likely to cause impairment of central 30 degrees of visual field.  A small red pin is introduced from periphery to center along the coronal plane and oblique meridians to check quadrantic field loss.
  103. 103. VISUAL FIELDSOPHTHALMICASSESSMENT  PERIPHERAL VISUAL FIELD  Examiner introduces large white pin from behind the patient and moved in an arc of 0.33 mts radius and peripheral visual field is assessed.  SUBJECTIVE VISUAL FIELD  Examiner sits opposite the patient, one eye of patient and examiner should be closed and fixes the other eye.  Red pin is moved in all quadrants adjecent to examiners eye and noted for color desaturation if any.  In traumatic chiasmatic damage, all the other findings except this are normal.
  104. 104. PUPILS OPHTHALMICASSESSMENT  DIRECT AND CONSENSUAL PUPILLARY REFLEXES  Penlight source is illuminated from below in each eye twice, first for the direct and next for consensual reflex
  105. 105. PUPILS OPHTHALMICASSESSMENT  SWINGING FLASH LIGHT TEST  Pupils were illuminated in same manner but light shined in each eye for 2 seconds and then swung rapidly to illuminate the other eye.  Afferent pupillary defect, unilateral third nerve palsy
  106. 106. RETINA OPHTHALMICASSESSMENT  PHOTO STRESS TEST  Visual acuity is recorded and one eye illuminated with bright light for 30 sec.  Visual acuity is again noted observing the recovery time.  Normal recovery time is 10 – 30 sec.  If more than this, retinal damage is suspected.
  107. 107. DISPLACEMENT OF GLOBEOPHTHALMICASSESSMENT  PROPTOSIS (EXOPHTHALMOS)  Hematoma and swelling of orbital tissue (commonly resolves spontaneously)  Subperiosteal hematoma, notably orbital roof  Inward displacement of orbital bone fragments (persistent proptosis)  ENOPHTHALMOS  Common late sequela, Initially masked by intraorbital tissue swelling and hematoma  Expansion of the orbit  Prolapse of soft tissue through a blow out fracture  Necrosis of soft tissue and fibrosis  Sucken upper lid may be present.
  108. 108. DISPLACEMENT OF GLOBEOPHTHALMICASSESSMENT  VERTICAL DISPLACEMENT  Commonly seen with orbital fractures.  In acute phase upward displacement due to hematoma and later phases downward displacement is commonly seen.  HORIZANTAL DISPLACEMENT  Laterally displaced – medial canthal ligament severed  Similar to squint  In both these cases corneal light reflexes are symmetrical and double vision is not seen.
  109. 109. Subconjunctival hemorrhage  Caused by vascular rupture beneath the bulbar conjunctiva or by osmotic increase of vascular wall  Treatment: 1)find out the cause 2)good explanation
  110. 110. Orbital Hematoma  Poor Vascular perfusion of the optic nerve and retina  Early recognition  “Gray Vision”  Proptosis  Ecchymosis  Subconjunctival hemorrhage  Afferent pupil defect  Hard globe
  111. 111. Orbital Hematoma  Treatment ◦ Lateral Canthotomy (immediately) ◦ Lateral canthal tendon lysis (immediately) ◦ IV acetazolamide 500mg ◦ IV mannitol 0.5 g/kg ◦ Surgical decompression of the orbit
  112. 112. INDIRECT CONSEQUENCESMAXILLOFACIALTRAUMA  TRAUMATIC RETINAL ANGIOPATHY  H/O loss of vision 24 to 48 hrs after injury  Mostly occurs after severe skull fracture, chest compression, long bones fractures.  Multiple discrete, superficial infarcts of retina accompanied by development of multiple cotton wool spots adjacent to optic nerve head.  No specific treatment.  In most of cases gradual recovery of vision in few months.
  113. 113. INDIRECT CONSEQUENCESMAXILLOFACIALTRAUMA  FACIAL PALSY  The degree of cover of cornea is determined.  Cornea is examined for any ulceration.  Ointment  Botulinum toxin into levator palpebrae superioris, results in complete ptosis for 4 to 6 weeks.  Tarsorraphy  PAPILLEDEMA  Optic nerve heads are to be examined in patients suspected with raised intra cranial pressure.
  114. 114. EYELID TRAUMA  Types ◦ Blunt ◦ Sharp/penetrating  classification ◦ lid margin  not involved  involved* ◦ canthal involved* *call ophthalmology ◦ canalicula involved*
  115. 115. EYE LID INJURIES MAXILLOFACIALTRAUMA  Eyelid swelling & hematoma  Commonly seen following orbital injuries  Spontaneous resolution in few weeks  Widening of medial canthus  Due to disruption of nasoethmoid complex  Trans nasal wiring
  116. 116. EYE LID INJURIES MAXILLOFACIALTRAUMA  EYE LID LACERATIONS  Should be repaired within 72 hrs.  Surgical repair should be done in layers accurately  First Margin should be restored with non absorbable suture passing through the gray line.  Tarsal plate is repaired with absorbable suture, only passing through partial thickness.  Any damage to levator should be carefully identified and repaired to prevent ptosis.
  118. 118. Eyelid Malpositions  Ectropion  Entropion  Blepharoptosis  Retraction
  119. 119. Ectropion  Outward turning of lid margin  Types: ◦ Congenital ◦ Involutional ◦ Paralytic ◦ Cicatricial ◦ Mechanical
  120. 120. Entropion  Inversion of the lid margin  Types: ◦ Congenital ◦ Acute-spastic ◦ Involutional ◦ Cicatricial
  121. 121. Blepharoptosis  Drooping or inferior displacement of the upper lid  Classification: ◦ Congenital vs acquired ◦ Myogenic, aponeurotic, neurogenic, mechanical, or traumatic ◦ Iimitators: dermatochalaisis and brow ptosis  Evaluation
  122. 122. HEMIFACIAL SPASM  Intermittent contractions of the entire side of face  Present during sleep  Compression of 7th nerve at the level of the brain stem  MRI evaluation
  123. 123. 7TH NERVE PALSY  Location of lesion: ◦ Supranuclear, brain stem, peripheral  Cause of paralysis: ◦ Bell’s ◦ Infection ◦ Infarct ◦ Demyelination ◦ Neoplasm ◦ Trauma ◦ Miscellaneous
  124. 124. NASO LACRIMAL INJURIES • Damage to naso lacrimal drainage system results in EPIPHORA • Any lacerations of middle third of lower eyelid should suspect injury to inferior canaliculus.(3/4th of tear volume evacuated) • Epiphora following nasal fractures is due to protective influence of medial canthal ligament. • Post operative epiphora - due to malposition of lower eyelid - due to malposition of bone fragments while reducing fracture fragments • Dacrocystorhinostomy • Canalicular lacerations are to be examined and addressed. MAXILLOFACIALTRAUMA
  125. 125. ORBITAL FRACTURES Orbital fractures can be divided into Anterior section - sturdy orbital rim Posterior section - comparitively thin lateral walls, roof & floor - these can be blow–in or blow–out Isolated orbital fractures accounts for 5% of mid facial fractures. Most common is the blow – out fracture. It can occur in the floor, medial and lateral walls. Commonly floor of the orbit is involved
  126. 126. BLOW – OUT FRACTURE
  127. 127. PATHOPHYSIOLOGY Bone conduction theory “buckling theory”  Less energy  Small fractures limited anterior floor Hydraulic theory  More energy  Larger fracture involving entire floor and medial wall  Should suspect more extensive orbit involvement with associated injuries
  128. 128. DIAGNOSIS HISTORY  Mechanism of injury  Double vision, blurry vision  Epistaxis  V2 numbness  Malocclusion  Nausea and vomiting (especially in children)  Forced duction test  CT Scan (sagittal)
  129. 129. Indications for Repair  Diplopia that persists beyond 7 to 10 days  Obvious signs of entrapment (positive forced duction test)  Relative enophthalmos greater than 2mm  Fracture that involves greater than 50% of the orbital floor (most of these will lead to significant enophthalmos when the edema resolves)  Entrapment that causes an oculocardiac reflex with resultant bradycardia and cardiovascular instability  Progressive V2 numbness
  130. 130. Immediate repair  Nonresolving oculocardiac reflex with entrapment ◦ Bradycardia, heart block, nausea, vomiting, syncope  Early enophthalos or hypoglobus causing facial asymmetry  “White-eyed” floor fracture with entrapment  When the criteria have been met, surgery performed as soon as possible  Dulley and fells mentioned 72% of enopthalmas in patients operated 6 months after injury and 20% when operated with in 14 days.
  131. 131. Repair Within Two Weeks  Symptomatic diplopia with positive forced duction test  Large floor fracture causing latent enophthalmos  Significant hypoglobus  Progressive infraorbital hypesthesia
  132. 132. Observation  Minimal diplopia ◦ Not in primary or downgaze  Good ocular motility  No significant enophthalmos  No significant hypoglobus
  133. 133. Trapdoor Fractures  Trapdoor fractures with entrapment differ in children and adults ◦ Children repaired within 5 days of injury do better that those repaired within 6-14 days or those repaired > 14 days ◦ There is no difference in early timing of adults (1-5 days or 6-14 days) ◦ Adults repaired less than 14 days from injury have less long term sequela than those repaired greater than 14 days from injury
  134. 134. TREATMENT  Reconstruction of orbital floor  AUTOLOGOUS GRAFT  Most favoured and high tissue compatibility  Inner aspect of anterior iliac crest  Posterior iliac crest  Calvarial bone  Lateral mandibular cortex  Lateral antral wall  Nasal septum
  135. 135. TREATMENT  ALLOGENIC MATERIAL  Lypophilised dura, allogenic bone and cartilage  ALLOPLASTIC MATERIAL  Polymeric silicone Polytetrafluoroethylene  Polyethylene Methyl methacrylate  Poly vinyl sponge Marlex mesh  Gelfilm Hydroxyapetite  0.62 mm threaded steinmann pin  Titanium flosor plate
  136. 136. MEDIAL WALL FRACTURES  Second most commonly disrupted orbital wall.  It causes entrapement or damage of medial rectus muscle and orbital wall.  Diagnosed consistently by limitation in abduction of the globe and globe retraction.  Forced duction test is mandatory  Axial CT scan is done to evaluate size and extent of defect
  137. 137. MEDIAL WALL FRACTURES  If amout of orbital tissue loss is minimal, not necesssary to seal the fracture site  When the defect is larger, reconstructed with alloplastic or allogenic materials and secured  Killian and lynch incision – curvelinear, made along the lateral wall of nose , 12 mm medial to medial palpebrea  Bicoronal flap
  138. 138. BLOW IN FRACTURES  Less common  Presents with proptosis because of decreased orbital volume  Restricted ocular motility  Dipolpia  Minimally displaced – no need of treatment  Immediate decompression with reconstruction
  139. 139. Proptosis  Infection  Inflammation  Congenital  Vascular  Neural  Mesenchymal  Lymphoid  Secondary  Lacrimal gland
  141. 141. Transconjunctival, Subciliary, Subtarsal Approaches
  142. 142. Transconjunctival Approach  Transconjunctival ◦ No visible scar ◦ Less incidence of ectropion and scleral show ◦ Poorer exposure without lateral canthotomy and cantholysis ◦ Better access to the medial orbital wall ◦ Risk of entropion
  143. 143. Subciliary Approach  Subciliary advantages ◦ Easier approach ◦ Scar camouflage ◦ Skin necrosis ◦ Highest incidence of ectropion ◦ Highest incidence of scleral show (a) Subciliary incision (b) Periosteum elevated and entrapped orbital contents freed (c) Defect repaired with synthetic material (d) Periosteum sutured
  144. 144. Subtarsal Approach  Subtarsal Advantages ◦ Easiest approach ◦ Direct access to floor ◦ Good exposure ◦ Postoperative edema the worst ◦ Visible scar
  145. 145. Dissection  Stay below orbital septum  24/12/6mm rule  Remove entrapped inferior rectus muscle  Slightly overcorrect if possible  Avoid V2 injury
  146. 146. Endoscopic Balloon catheter repair  Wide MMA  Insert Foley and inflate  Leave in place for 7-10 days  Best for large trapdoor fractures without entrapment  Broad spectrum antibiotics
  147. 147. ORBITAL INFECTIONSORBITALINFECTIONS Anatomical proximity, common blood supply and lymphatic drainage. All sinuses share common bony wall with orbit – prone to infections from sinuses Thin walls of orbit Periorbita is loosely attached to bone except at the rim and apex Relatively closed compartment
  148. 148. CLASSIFICATIONORBITALINFECTIONS STAGE I Preseptal cellulitis. Infection is confined to the lids and periocular soft tissue anterior to orbital septum. orbit may be inflamed secondarily but not directly infected STAGE II Orbital cellulitis with proptosis, limitations in movements, and possible optic nerve compromise. STAGE III Orbital cellulitis with a subperiosteal abscess STAGE IV Orbital cellulitis with a true orbital abscess within the orbital fat STAGE V Retro orbital spread of the infection into the cavernous sinus or brain
  149. 149. INFECTION  Preseptal Cellulitis ◦ Vision, motility, pupils, disc are normal ◦ globe itself is not proptotic  Orbital Cellulitis ◦ 90% secondary to sinus disease ◦ high risk of morbidity and mortality
  150. 150. PRESEPTAL CELLULITISORBITALINFECTIONS  PRIMARY SOURCES i. Paranasal sinusitis ii. Upper respiratory tract infection iii. Direct inoculation • SIGNS AND SYMPTOMS • H/O swelling of eyelids • Spread of infection confined to the lid • Chemosis may be present • Proptosis, limitation in eye movements, optic nerve dysfunction are not present • CT SCAN to rule out any orbital involvement has to be done.
  151. 151. ORBITAL CELLULITIS & ABSCESSORBITALINFECTIONS • Infection of retroseptal soft tissue of the orbit • Serious condition that should be quickly diagnosed and treated • Mostly occurs in children and spreads from sinuses • Typically begins with painful swelling of the eyelids and chemosis is seen mostly • Distuingished from preseptal cellulitis by presence of proptosis, limitation of ocular movements, pupillary dysfunction and optic nerve damage • Should be diagnosed radiographically
  152. 152. IMAGING OPTIONS  Plain films  CT scan  MRI  Ultrasound
  153. 153. THANK YOU