ORBIT & EYEDr.N.R.K.ANIL KUMAR,1ST MDS,DEPARTMENT OF OMFS,VISHNU DENTALCOLLEGE.SEMINAR
“I am a camera with its shutteropen, quite passive, recording,not thinking.”The human eyeblinks an average of12 times a min /4,200,000 times ayear.All babies are colourblind when they areborn and do notproduce tears untilthe baby isapproximately six toeight weeks old.People generallyread 25% slowerfrom a computerscreencompared topaper.Itsimpossible tosneeze withyour eyesopen.INTRODUCTION
CONTENTSDEVELOPMENTANATOMY OF ORBITANATOMY OF EYEANATOMY OF EYELIDLACRIMAL APPARATUSBLOOD SUPPLYNERVE SUPPLYOPTHOLMOLOGICAL EXAMINATIONMAXILLOFACIAL TRAUMAMAXILLOFACIAL INFECTIONSCONTENTS
DEVELOPMENT The eye develops from several types of tissues.i. Retina & RPE – Neural Ectodermii. Lens – Surface Ectodermiii. Sclera &Anterior Chamber – Migrating Cells. Optic Vesicle Lens Placode Mesenchyme Visceral MesodermMutations in the SHHgene or inhibition ofprotein processingresults in cyclopia. Thephenotype results in asingle eye in the centerof the face.DEVELOPMENT
OPTIC VESICLEoThe primary optic vesiclesarise as an evagination ofneural tube epithelium.oThe optic vesicle isconnected to theprocencephalon by theoptic stalk, which willbecome the optic nerve.oIn humans, eyedevelopment isn’tcompleted until severalmonths after birth.DEVELOPMENT
•The lens placode is induced by contact between theoptic vesicle and the overlying ectoderm.•The optic vesicle infolds, forming a bilayered opticcup. The inner wall of the optic cup becomes theneural retina, while the outer wall becomes thepigment epithelium•The lens placode then invaginates and pinches off toform a hollow lens and is subsequently filled withdifferentiating primary fiber cells that elongate from theLENS PLACODEDEVELOPMENT
•The surface ectoderm from which the lens vesicleforms gives rise to the cornea.•The iris and ciliary body develop at the periphery ofthe retina.•Unlike the other muscles of the body, part of the iris isderived from the ectodermal layer.•Migrating mesenchymal tissues form the sclera,trabecular meshwork, and anterior chamber.DEVELOPMENT
DEVELOPMENT At birth, the eye is relatively large in relation to the restof 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 pigmenton the anterior surface. During early infant life, the cornea & sclera can bestretched by raised IOP → enlargement of the eye.DEVELOPMENT
ORBITORBIT Orbit / eye socket isroughly irregular foursided pyramid located oneither side of root of nose. Base - at the orbitalopening Apex - at optical canal Axis directed posteriorlyand medially Medial walls - nearlyparallel Medial and lateral wallsmakes an angle of 4525mm
ORBITAL CAVITYCONTRIBUTED BY 7 BONES Frontal bone Zygomatic bone Maxilla Ethmoid bone Sphenoid bone Lacrimal bone Palatine boneENTRANCE OF THE ORBIT Frontal, Zygomatic, Maxillary BonesORBITORBIT
ROOF Orbital plate of frontal bone Posteriorly small portion contributed by lesser wingof sphenoid. Anteriomedially frontal sinus is present in thefrontal bone. Supra orbital foramen is present at junction ofmedial and middle half.ORBIT
FLOOR Orbital plate of maxilla Anteriolaterally- zygomatic bone Posteriomedially- orbital process of palatine bone On the lateral side, anteriorly continues with thelateral wall but separated posteriorly by inferiororbital fissure. It roofs maxillary sinus Its thin and is most commonly fractured.ORBIT
MEDIAL WALL Orbital plate of ethmoid bone (lamina papyracia) Anteriorly – lacrimal bone At the apex – body of sphenoid Lacrimal bone contains fossa for nasolacrimal sacORBIT
L ATERAL WALL Frontal process of zygomatic bone anteriorly andthe orbital surface of greater wing of sphenoidposteriorly. Thickest wall of the orbit Orbital tubercle – lateral palpebral ligament Continuous with roof anteriorly and separatedposteriorly by superior orbital fissureORBIT
COMMUNICATIONSORBITALCAVITYOPTIC CANAL Located between two roots that connect lesserwing of sphenoid with body of sphenoid Connects orbit and middle cranial fossa Transmits optic nerve, menengial sheaths,opthalmic artery
COMMUNICATIONSORBITALCAVITYSUPERIOR ORBITAL FISSURE Gap between greater and lesser wings of sphenoid Connects orbit and cranial cavity Transmits occulomotor, trochlear, opthalmic,abduscens nerves and opthalmic veins
COMMUNICATIONSORBITALCAVITYINFERIOR ORBITAL FISSURE Bounded byAbove – greater wing of sphenoidBelow – maxillaLaterally – zygomatic bone Connects orbit with pterigopalatine andinfratemporal fossa Transmits infraorbital, zygomatic branches ofmaxillary nerve and vessels, orbital rami ofpterigopalatine ganglion
COMMUNICATIONSORBITALCAVITY ETHMOIDAL FORAMEN At the junction of frontal and ethmoid bones,anteriorly and posteriorly Connects with ethmoid sinuses, anterior cranialfossa, nasal cavity. Openings for Zygomatico temporal andzygomatico facial nerves In the lateral wall on zygomatic surface
CONTENTSORBITALCAVITY 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
CONJUNCTIVA Mucous membrane withnon keratinized squamousepithelium and globletcells. Extends from limbus tocover interior eyelids. Thin, richly vascularizedsubstantia propria Can be divided into threegeographic zones:◦ Palpebral◦ Forniceal◦ BulbarEYEBALL
CORNEA• The cornea occupies the center of theanterior pole of the globe.• It measures12 mm horizontally & about 11 vertically.• The cornea is transparent and highly innervated.• It is avascular, gets O2 & nutrients from aqueoushumor and outside surface.• Kept moist by tears.• Responsible for most of the eye’s ability to refractand focus lightEYEBALL
SCLERAEYEBALL• The sclera covers the posterior four fifths of the surfaceof the globe, with an anterior opening for the corneaand a posterior opening for the optic nerve• Composed of dense fibrous connective tissue, almostavascular• 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
CHOROID The choroid, the posterior portion of the uvealtract, nourishes the outer portion of the retina. Itaverages 0.25 mm in thickness and consists ofthree layers of vessels: The choriocapillaris, the innermost layer A middle layer of small vessels An outer layer of large vesselsEYEBALL
IRISEYEBALL• Colored structure surrounding the pupil.• Controls amount of light entering the eye• Controls the size of the pupil through the sphincterpupillae (shrinks pupil) and a diffuse dilator pupillae(enlarges pupil)• Spongy stroma with melanocytes: faces anteriorchamber• Pigmented epithelium faces posterior chamber. Thisepithelium becomes the ciliary body laterally.• When it is full open, it is about f/2 and f/3. Thishappens at
CILIARY BODY Triangular in cross section. The apex of the ciliary body is directed posteriorlytoward 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 theepithelium of ciliary body. Nourishes cornea, lens,iris, corneal endothelium, & stroma. Secreted intoposterior chamber, flows around iris through pupilto “the angle”◦ It also plays a role in the trabecular anduveoscleral outflow of aqueous humor◦ AccommodationEYEBALL
LENS The lens is a biconvex structure located directly behindthe posterior chamber and pupil Diameter of about 9-10 mm & width of about 6 mm. lens fibers: extremely long cells with no nuclei, stretchanterior to posterior. Cytoplasm filled with crystallin,arranged in a regular lattice Lens capsule: thick basement membrane surroundinglens. Attachment site for the zonules. The lens has certain unusual features. It lacksinnervation and is avascular. Transparent because ofanucleate nature and fibers containing crystallineproteins.EYEBALL
RETINA Photoreceptors: contain photopigment in discslocated within outermost segment. When lightinteracts with the photo pigment, conformationalchange and neural signal Blood supply: central retinal artery enters throughoptic disk and ramifies in the inner surface of retina Capillary network of the choroid, thechoroicapillaris supplies photoreceptors throughBruch’s membrane and the RPE 2 types of photoreceptors:◦ Rods: sensitive in dim light, not wavelengthsensitive◦ Cones: sensitive in bright light, differentialsensitivity to wavelength. Three kinds of conesare - red, green, and blue. These cones worktogether to help us see millions of colors.EYEBALL
CHAMBERSEYEBALLIris and lens separate eye into three chambersVitreous chamber : largest chamber, posterior tolens, filled with gel like vitreous humourAnterior chamber : between cornea and irisPosterior chamber : between iris and lensBoth are filled with aqueous humour, which providesnourishment to avascular lens and cornea
VITREOUS The vitreous cavity occupies four fifths of thevolume of the globe Important to the metabolism of the intraoculartissues because it provides a route formetabolites used by the lens, ciliary body andretina serves as a medium to maintain the path of lightbetween 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 vitreousis 99% water Its viscosity is approximately twice that of water,mainly because of the presence of themucopolysaccharide, hyaluronic acid.EYEBALL
ACCOMMODATION The lens changes shape to focus light on the back of theeye regardless of the distance of the object Cornea curvature is fixed, so focus comes from changesin the lens curvature through the ciliary muscles Lens with no tension: would be curved/round normal state of lens: flattened by the tension of thezonules/suspensatory ligaments. To curve lens: ciliary muscles contract and ciliary bodymoves closer to the lens. Zonules go slack. To flatten the lens: ciliary muscles relax, ciliary bodymoves away from the lens. Stretches the zonules.EYEBALL
Myopia (Near-sightedness) This person can see close objects clearly, but hastrouble seeing distant objects. Usually occurs because the distance between thelens and the retina is too large or because thecornea-lens combination converges light toostrongly. Light from distant objects is brought into focus infront of the retina.MYOPIA
Hyperopia (Far-sightedness)• This person had no problem seeing objects in thedistance, but has trouble seeing nearby objects.• The eye cannot refract light well enough to form animage on the retina.• Usually occurs because the distance between thelens and the retina is too small or because thecornea-lens combination is too weak. Light fromnearby objects focuses behind the retina.HYPEROPIA
Even within the cone and rod system, your retinaadjusts its sensitivity in response to the overall lightlevel When you walk into a dark room, you can’t seeanything, but after a few minutes, you adapt and canstart to see things and vice- versa. Dark adaptation is a slow process, but allows us tosee in a huge range of light levelsDARKADAPTION CLINICAL CORRELATIONS
CLINICAL TERMS Glaucoma:Elevated intraocular pressure from overproductionof aqueous humor or blockage in drainage. Highpressure in the anterior chamber transducedthrough vitreous body, pressure on retina. Candamage neural retina by impeding blood flow inreitinal 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 anormal eye, the crystalline lens is almosttransparent, however injury, age or disease cancause the lens to eventually lose its clarity.CLINICALTERMS
CLINICAL TERMSCLINICALTERMS Hemianopia:Blindness in one-half of the visual field Amblyopia: (lazy eye)Decreased vision in one eye that leads to the useof the other eye as the dominant eye. A problemmost commonly associated with children. Presbyopia:Progressive loss of vision which begins in mid-life.Near vision becomes blurry, making readingglasses necessary. Over time, the blurrinessextends to intermediate vision, making computerglasses useful. Bifocals are worn to improve nearvision and distance vision if necessary.• Diplopia (double vision)The perception of two images of a single object.
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 looksstraight ahead. Nystagmus:Rapid and uncontrollable eye movements. aninvoluntary, constant, rhythmic movement of theeyeball that can be congenital or caused by aneurological injury or drug use AnisocoriaA condition in which the pupils are unequal in size. thiscondition can be congenital or caused by a head injury,aneurysm or pathology of the central nervous system
CLINICAL TERMSCLINICALTERMS• Chalazion :A slowly developing lump that forms due toblockage and swelling of an oil gland in the eyelid.• papilledema (chocked disk)swelling and inflammation of the optic nerve at thepoint of entrance into the eye through the opticdisk. this swelling is caused by increasedintracranial pressure and can be due to a tumorpressing on the optic nerve• Scotoma (blind spot)An abnormal area of absent or depressed visionsurrounded by an area of normal vision• Bitot spots : Raised, silvery white, foamy, triangular
CLINICAL TERMSCLINICALTERMS Astigmatism:An eye condition where the eye cannot focus lightuniformly in all directions resulting from an irregularcurvature. Astigmatism results in mild tomoderately blurred vision and/or eyestrain. Floaters and Spots:A generalized term used to describe small specksmoving subtly but noticeably in your field of vision.A floater or a spot is likely a tiny clump of gel orcells in the vitreous. Aging, eye injury andbreakdown of the vitreous are the main causes offloaters and spots.• Subconjunctival hemorrhageBleeding between the conjunctiva and the sclera.
CLINICAL TERMSCLINICALTERMS Pterygium:A raised growth on the eye that is most often directlyrelated to over-exposure to the sun. Dry, dustyconditions may also contribute to development of thesegrowths. Protecting your eyes from UV radiation is acritical preventive measure. Blepharitis:Inflammation of the eyelids. It can have a variety ofcauses, such as an allergic reaction, bacterial infection,or excess oil produced by eyelid glands. DacroadenitisAn inflammation of the lacrimal gland that can becaused by a bacterial, viral or fungal infection. signsand symptoms include the sudden severe pain, rednessand pressure in the orbit of the eye Keratoconus:An inherited corneal disease. The cornea graduallybecomes thinner and less able to maintain its shapeagainst the pressure of the fluids inside the eye.
VISUAL PATHWAYRetinaOpticnerveOpticchiasmOptictractLateralgeniculate bodyopticradiationoccipital lobeoptical center
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 forthe anesthetist)
Oculocardiac Reflex Stimulation causes to activation of an Afferent Arcvia CN V, trigeminal. Efferent Arc via CN X, vagus. Treatment: STOP STIMULATION! Verify adequate ventilation & oxygenation Atropine IVP .01-.02mg/kg (pretx does not alwaysprevent reflex) May also need local anesthetic infiltration Via retrobulbular block or peribulbar block. Severe Cases: May need to perform CPR.
Oculocardiac Reflex Reflex usually subsides with repeatedstimulation More common in strabismus surgerywith pediatric pts. Can occur in all age groups. Be vigilant, be prepared.
EYELIDEYELIDAn eyelid is a thin fold of skin that covers andprotects an eye.
THE LID MARGIN When eye is open, the upper lid covers about1/6th of the cornea & the lower lid just touchesthe limbus. It is About 2mm broad and is divided into twoparts by punctum. The medial, lacrimal portion is rounded anddevoid of lashes or glands. The lateral, ciliary portion consist of roundedanterior border, a sharp posterior border and aninter-marginal strip. The medial canthus is about 2mm higher thanthe lateral canthus
LAYERS OF EYE LIDEYELIDAnterior (cutaneous) to posterior (conjunctiva) Skin Subcutaneous tissue. Striated muscle (orbicularis). Submuscular areolar tissue. Orbital fat Fibrous layer with tarsal plates. Mucous membrane or Conjunctiva.
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 distendedby oedema or blood.3.THE LAYER OF STRIATED MUSCLE:-It consist of orbicularis muscle which comprises threeportions:-i.The orbitalii.The palpebraliii.The lacrimalIt closes the eyelids & is supplied by zygomatic branch ofthe facial nerve.
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 andperipheral septum orbitale.a.) Tarsal plate:There are two plates of dense connective tissue, which giveshape and firmness to the lids.Both join with each other at medial and lateral canthi andattached to the orbital margins through medial and lateralpalperable ligaments
b.) Septum orbitaleIt is thin membrane of connective tissue perforated bynerves , vessels and LPS muscle, which enter the lidsfrom the orbit.6. LAYER OF NON-STRIATED MUSCLE FIBRES:It consist of the palpebral muscle of muller which lies deepto the septum orbitale in both the lids.In the upper lid it arises from the fibres of LPS muscle and inthe lower lid from prolongation of the inferior rectusmuscle; and is inserted on the peripheral margins of thetarsal plate.It is supplied by sympathetic fibres.
NERVES OF LIDS Motor supplyFacial - supplies orbicularis muscle,Oculomotor - supplies LPS muscleSympathetic fibres - supply the muller’s muscle. Sensory supplyFrom branches of the trigeminal nerve.
RECTI MUSCLES Four in number, approximately strap shaped Attached to common tendinous ring Each rectus passes forwards and attached totendinous expansion into the scleraEYEMUSCLES
MUSCLE ACTIONSuperior rectus Upwards and mediallyInferior rectus Downards and mediallyMedial rectus Medial movement ( adduction )Lateral rectus Lateral movement ( abduction )EYEMUSCLES
OBLIQUES SUPERIOR OBLIQUE Fusiform muscle Arises from body of sphenoid, passes throughtrochlear fossa of frontal bone, attached to sclerabetween superior and lateral recti muscles Moves the eye laterally and intrudes the eyeballEYEMUSCLES
OBLIQUES INFERIOR OBLIQUE Lies near anterior margin of floor of orbit Inserted into the lateral part of the sclera behindthe equator of eyeball Moves eye laterally and causes extorsionEYEMUSCLES
LEVATOR PALPEBRAESUPERIORIS• Thin triangular muscle• Arises from inferior aspect of lesser wing ofsphenoid• Ends in wide aponeurosis, some fibers attaches toanterior end of tarsal plate and others to the skinof eyelid• Laterally passes between orbital and palpebralparts of lacrimal gland and attached to the orbitaltubercle• Medially continues as loose connective tissue onmedial palpebral ligament• Innervated by occulomotor nerve• Elevates upper eyelid• Linked to superior rectus by check ligament, thusupper eyelid elevates when eye directed upwardsEYEMUSCLES
Cranial Nerve III(Occulomotor)• It supplies all the extraocular muscles except thesuperior oblique and the lateral rectus• It also carries cholinergic innervation to thepupillary sphincter and the ciliary muscle• The CN III nucleus consists of several distinct,large motor cellsubnuclei, each of which subserves the extraocularmuscle it innervates• The Edinger-Westphal nucleus provides theparasympathetic preganglionic efferent innervationto the ciliary muscle and pupillary sphincterNERVESUPPLY
Cranial Nerve III CN III usually divides into superior and inferiordivisions The superior division of CN III innervates thesuperior rectus and levator palpebrae muscles. The larger inferior division splits into three branchesto supply the medial and inferior rectus muscles andthe inferior oblique. The parasympathetic fibers enter the inferiordivision, and course through the branch that suppliesthe inferior oblique muscle and join the ciliaryganglion. They synapse with the postganglionic fibers, whichemerge as many short ciliary nerves.NERVESUPPLY
Cranial Nerve IV (Trochlear) Cranial nerve IV has the longest intracranial course The CN IV the only cranial nerve that is completelydecussated and the only motor nerve to exit dorsallyfrom the nervous system. CN IV enters the orbit through the superior orbitalfissure outside the annulus of Zinn and runssuperiorly to innervate the superior oblique muscleNERVESUPPLY
Cranial Nerve V (Trigeminal) The largest cranial nerve Possesses both sensory and motor divisions Thesensory portion subserves the greater part of thescalp, forehead, face, eyelids, eye, lacrimal gland,extraocular muscles, ear, dura mater, and tongue The motor portion innervates the muscles ofmastication through branches of the mandibulardivisionNERVESUPPLY
Cranial Nerve VI (Abducens) The nucleus of cranial nerve VI is situated in thefloor of the fourth ventricle, beneath the facialcolliculus, in the caudal pons CN VI runs below and lateral to the carotid arteryand may transiently carry sympathetic fibers fromthe carotid plexus It passes through the superior orbital fissure withinthe annulus of Zinn and innervates the lateralrectus muscle on its ocular surfaceNERVESUPPLY
CILIARYGANGLIONCILIARY GANGLION Para sympathetic ganglion which is asmall, flat, reddish grey swelling 1-2 mmdiameter, located near the apex of orbitmedial to superior orbital fissure. Three types of nerve fibers run throughthe ganglion: 1. parasympathetic fibers2.sympathetic fibers3.sensory fibers Only parasympathetic fibers formsynapses in the ganglion and other twotypes of nerve fibers simply passthrough.
CONNECTIONSCiliary nerve innervates two muscles1.Sphincter pupillae:constricts the pupil, a movement known as Miosis.2.Ciliaris muscle:Releasing tension on the , making the lens more convex, alsoknown as accommodationCILIARYGANGLION
Orbital Fat Contains two compartments: Central compartment (retrobulbar &intracone) Peripheral compartment (peribulbar &pericone)The importance of the orbital fat, is that itcontains the motor & sensory nerves for theeye.Therefore regional anesthesia can be injectedinto the fat and provide the patient with aneffective block.
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 orredness 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
First-Aid Techniques◦ Chemical burns Flush the eye immediately with water or anydrinkable liquid and continue flushing for at least15 minutes. For caustic or basic solutions, continueflushing whileon the way to the doctor. Flush the eye even if it has a contact lens. Flushingover the lens may dislodge it.◦ Blows to the eye Apply a cold compress without pressure. Tape a plastic bag containing crushed ice to theforehead 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,
MAKE EYE SAFETY•BLOOD SPLASH INJURY•Disposable surgical masks with full-face visors have beenshown to offer the highest level of protection from blood splashinjury•The use of masks and visors should be standard practice for alltheatre staff, including assistants, scrub nurses and observers.•If such an incident occur, a procedure similar to that used forneedle-stick injury may be followed.•The eye should first be rinsed thoroughly to remove as much ofthe fluid as possible.•Serology should be ordered promptly to obtain a baseline forfuture comparisons.•Hiv screen and acute hepatitis screen are indicated.•Post-exposure prophylaxis (pep) should be initiated as soon aspracticable unless the patient is known to be HIV, HBV and HCVnegative.
OPHTHALMICASSESSMENTOPHTHALMICASSESSMENT Ophthalmic assessment is mandatory for everypatient who has sustained mid facial trauma severeenough to cause a fracture. HISTORY- Time, place, nature of injury- whether glasses were worn at the time ofinjury- antecedent visual status- whether any squit or other abnormalitiespresentbefore the injury
VISUAL ACUITYOPHTHALMICASSESSMENT• Measure of resolving power of the eye• Recorded as a fractiondistance of the patient from the chartline he / she sees at that distancePRINCIPLE : Two distinct points appear as separateonly when they subtend an angle of 1 minute atnodal plane of the eye.Each test letter is designed as it subtends an angle of5 minutes at nodal plane of eye.
VISUAL ACUITYOPHTHALMICASSESSMENT• SNELLEN’S CHART• Patient at 6 mts from snellen’schart.• Test letters are constructed sothat edges subtend a visualangle of 1min of arc.• For normal eye with 6/6 vision,each complete test lettersubtends 5 min of arc at theeye.• If patient cant read at 6/6 anddoesn’t have glasses before,patient is asked to see throughpin hole. If acuity increases
VISUAL ACUITYOPHTHALMICASSESSMENT When visual acuity is less and patient cant read ,then measured by counting fingers.(CF) If acuity is still less, then hand movements arerecorded.(HM) For patients with polytrauma acuity for near visioncan be measured as snellens letters subtendssame angle at 0.33 mts.
VISUAL FIELDSOPHTHALMICASSESSMENT Assessed in patients with sustained severe headtrauma CENTRAL VISUAL FUNCTION Patient is asked to look at red object and x-rayilluminator with each eye separately and comparethe color and brightness perceived respectively. Color desaturation – traumatic optic neuropathy Decreased brightness – optic nerve damage Patient is told to look at the examiners nose witheach eye separately and asked whether any part offace is missing or blurred. This detects paracentralscotoma (choroidal tear)
VISUAL FIELDSOPHTHALMICASSESSMENT BINOCULAR VISUAL FIELD TESTING Examiner sits opposite to patient at 1mt lookinginto his eyes. Hands were placed in outer quadrants and askedto identify the finger movements. Patients suspected of left homonymoushemianopia when left field of vision is defecit. CENTRAL VISUAL FIELD TO CONFRONTATION Traumatic damage to visual pathways is morelikely to cause impairment of central 30 degrees ofvisual field. A small red pin is introduced from periphery tocenter along the coronal plane and obliquemeridians to check quadrantic field loss.
VISUAL FIELDSOPHTHALMICASSESSMENT PERIPHERAL VISUAL FIELD Examiner introduces large white pin from behindthe patient and moved in an arc of 0.33 mts radiusand peripheral visual field is assessed. SUBJECTIVE VISUAL FIELD Examiner sits opposite the patient, one eye ofpatient and examiner should be closed and fixesthe other eye. Red pin is moved in all quadrants adjecent toexaminers eye and noted for color desaturation ifany. In traumatic chiasmatic damage, all the otherfindings except this are normal.
PUPILSOPHTHALMICASSESSMENT DIRECT AND CONSENSUAL PUPILLARYREFLEXES Penlight source is illuminated from below in eacheye twice, first for the direct and next forconsensual reflex
PUPILSOPHTHALMICASSESSMENT SWINGING FLASH LIGHT TEST Pupils were illuminated in same manner but lightshined in each eye for 2 seconds and then swungrapidly to illuminate the other eye. Afferent pupillary defect, unilateral third nerve palsy
RETINAOPHTHALMICASSESSMENT PHOTO STRESS TEST Visual acuity is recorded and one eye illuminatedwith bright light for 30 sec. Visual acuity is again noted observing the recoverytime. Normal recovery time is 10 – 30 sec. If more than this, retinal damage is suspected.
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 byintraorbital 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.
DISPLACEMENT OF GLOBEOPHTHALMICASSESSMENT VERTICAL DISPLACEMENT Commonly seen with orbital fractures. In acute phase upward displacement due tohematoma and later phases downwarddisplacement is commonly seen. HORIZANTAL DISPLACEMENT Laterally displaced – medial canthal ligamentsevered Similar to squint In both these cases corneal light reflexes aresymmetrical and double vision is not seen.
Subconjunctival hemorrhage Caused by vascular rupture beneath the bulbarconjunctiva or by osmotic increase of vascularwall Treatment:1)find out the cause2)good explanation
Orbital Hematoma Poor Vascular perfusion ofthe optic nerve and retina Early recognition “Gray Vision” Proptosis Ecchymosis Subconjunctivalhemorrhage Afferent pupil defect Hard globe
Orbital Hematoma Treatment◦ Lateral Canthotomy(immediately)◦ Lateral canthal tendonlysis (immediately)◦ IV acetazolamide500mg◦ IV mannitol 0.5 g/kg◦ Surgicaldecompression of theorbit
INDIRECT CONSEQUENCESMAXILLOFACIALTRAUMA TRAUMATIC RETINALANGIOPATHY H/O loss of vision 24 to 48 hrs after injury Mostly occurs after severe skull fracture, chestcompression, long bones fractures. Multiple discrete, superficial infarcts of retinaaccompanied by development of multiple cottonwool spots adjacent to optic nerve head. No specific treatment. In most of cases gradual recovery of vision in fewmonths.
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 patientssuspected with raised intra cranial pressure.
EYELID TRAUMA Types◦ Blunt◦ Sharp/penetrating classification◦ lid margin not involved involved*◦ canthal involved* *call ophthalmology◦ canalicula involved*
EYE LID INJURIESMAXILLOFACIALTRAUMA 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
EYE LID INJURIESMAXILLOFACIALTRAUMA EYE LID LACERATIONS Should be repaired within 72 hrs. Surgical repair should be done in layers accurately First Margin should be restored with nonabsorbable suture passing through the gray line. Tarsal plate is repaired with absorbable suture,only passing through partial thickness. Any damage to levator should be carefullyidentified and repaired to prevent ptosis.
Entropion Inversion of the lidmargin Types:◦ Congenital◦ Acute-spastic◦ Involutional◦ Cicatricial
Blepharoptosis Drooping or inferior displacement ofthe upper lid Classification:◦ Congenital vs acquired◦ Myogenic, aponeurotic, neurogenic,mechanical, or traumatic◦ Iimitators: dermatochalaisis and browptosis Evaluation
HEMIFACIAL SPASM Intermittent contractions ofthe entire side of face Present during sleep Compression of 7th nerveat the level of the brainstem MRI evaluation
7TH NERVE PALSY Location of lesion:◦ Supranuclear, brainstem, peripheral Cause of paralysis:◦ Bell’s◦ Infection◦ Infarct◦ Demyelination◦ Neoplasm◦ Trauma◦ Miscellaneous
NASO LACRIMAL INJURIES• Damage to naso lacrimal drainage system results inEPIPHORA• Any lacerations of middle third of lower eyelid shouldsuspect injury to inferior canaliculus.(3/4th of tearvolume evacuated)• Epiphora following nasal fractures is due to protectiveinfluence of medial canthal ligament.• Post operative epiphora- due to malposition of lower eyelid- due to malposition of bone fragments whilereducing fracture fragments• Dacrocystorhinostomy• Canalicular lacerations are to be examined andaddressed.MAXILLOFACIALTRAUMA
ORBITAL FRACTURESOrbital fractures can be divided intoAnterior section- sturdy orbital rimPosterior section- comparitively thin lateral walls, roof & floor- these can be blow–in or blow–outIsolated orbital fractures accounts for 5% of mid facialfractures.Most common is the blow – out fracture.It can occur in the floor, medial and lateral walls.Commonly floor of the orbit is involved
Indications for Repair Diplopia that persists beyond 7 to 10 days Obvious signs of entrapment (positive forcedduction test) Relative enophthalmos greater than 2mm Fracture that involves greater than 50% of theorbital floor (most of these will lead to significantenophthalmos when the edema resolves) Entrapment that causes an oculocardiac reflex withresultant bradycardia and cardiovascular instability Progressive V2 numbness
Immediate repair Nonresolving oculocardiacreflex with entrapment◦ Bradycardia, heart block,nausea, vomiting, syncope Early enophthalos orhypoglobus causing facialasymmetry “White-eyed” floor fracturewith entrapment When the criteria have beenmet, surgery performed assoon as possible Dulley and fells mentioned72% of enopthalmas inpatients operated 6 monthsafter injury and 20% whenoperated with in 14 days.
Repair Within Two Weeks Symptomatic diplopia with positive forced ductiontest Large floor fracture causing latent enophthalmos Significant hypoglobus Progressive infraorbital hypesthesia
Observation Minimal diplopia◦ Not in primary or downgaze Good ocular motility No significant enophthalmos No significant hypoglobus
Trapdoor Fractures Trapdoor fractures with entrapment differ inchildren and adults◦ Children repaired within 5 days of injury dobetter that those repaired within 6-14 days orthose 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 injuryhave less long term sequela than those repairedgreater than 14 days from injury
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
MEDIAL WALL FRACTURES Second most commonly disrupted orbital wall. It causes entrapement or damage of medial rectusmuscle and orbital wall. Diagnosed consistently by limitation in abduction ofthe globe and globe retraction. Forced duction test is mandatory Axial CT scan is done to evaluate size and extentof defect
MEDIAL WALL FRACTURES If amout of orbital tissue loss is minimal, notnecesssary to seal the fracture site When the defect is larger, reconstructed withalloplastic or allogenic materials and secured Killian and lynch incision – curvelinear, made alongthe lateral wall of nose , 12 mm medial to medialpalpebrea Bicoronal flap
BLOW IN FRACTURES Less common Presents with proptosis because of decreasedorbital volume Restricted ocular motility Dipolpia Minimally displaced – no need of treatment Immediate decompression with reconstruction
Transconjunctival Approach Transconjunctival◦ No visible scar◦ Less incidence of ectropionand scleral show◦ Poorer exposure withoutlateral canthotomy andcantholysis◦ Better access to the medialorbital wall◦ Risk of entropion
Endoscopic Balloon catheterrepair Wide MMA Insert Foley and inflate Leave in place for 7-10 days Best for large trapdoor fractures withoutentrapment Broad spectrum antibiotics
ORBITAL INFECTIONSORBITALINFECTIONSAnatomical proximity, common blood supply andlymphatic drainage.All sinuses share common bony wall with orbit –prone to infections from sinusesThin walls of orbitPeriorbita is loosely attached to bone except at therim and apexRelatively closed compartment
CLASSIFICATIONORBITALINFECTIONSSTAGE I Preseptal cellulitis. Infection is confined to the lids andperiocular soft tissue anterior to orbital septum. orbit may beinflamed secondarily but not directly infectedSTAGE II Orbital cellulitis with proptosis, limitations in movements, andpossible optic nerve compromise.STAGE III Orbital cellulitis with a subperiosteal abscessSTAGE IV Orbital cellulitis with a true orbital abscess within the orbitalfatSTAGE V Retro orbital spread of the infection into the cavernous sinus orbrain
INFECTION Preseptal Cellulitis◦ Vision, motility, pupils, disc arenormal◦ globe itself is not proptotic Orbital Cellulitis◦ 90% secondary to sinus disease◦ high risk of morbidity and mortality
PRESEPTAL CELLULITISORBITALINFECTIONS PRIMARY SOURCESi. Paranasal sinusitisii. Upper respiratory tract infectioniii. 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, opticnerve dysfunction are not present• CT SCAN to rule out any orbital involvement hasto be done.
ORBITAL CELLULITIS & ABSCESSORBITALINFECTIONS• Infection of retroseptal soft tissue of the orbit• Serious condition that should be quickly diagnosedand treated• Mostly occurs in children and spreads fromsinuses• Typically begins with painful swelling of the eyelidsand chemosis is seen mostly• Distuingished from preseptal cellulitis by presenceof proptosis, limitation of ocular movements,pupillary dysfunction and optic nerve damage• Should be diagnosed radiographically