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O OC CU UL LA AR RM MO OV VE EM ME EN NT TS S & & S ST TR RA AB BIIS SM MU US S By Dr. Mirza Shafiq Ali Baig Dr. Farnaz Siddiqui OCULAR MOVEMENTS • Ductions – – • Monoocular movements around the axes of Fick. Adduction, abduction, elevation, depression, intorsion and extorsion. Version – – – – Binocular, simultaneous ,conjugate movements in the same directions. Dextroversion and levoversion Dextroelevation and levoelevation Dextrodepression and levodepression. OCULAR MOVEMENTS • Vergences – Binocular, simultaneous, disjugate or disjunctive movements in opposite directions. – Convergence and divergence. ANATOMY OF THE EOM’S Six Extraocular muscles surround each eye: • • • • • • Medial Rectus Lateral Rectus Superior Rectus Inferior Rectus Superior Oblique Inferior Oblique ANATOMY OF THE EOM’S Medial Rectus • Origin: Annulus of Zinn • Insertion: 5.5mm behind the nasal limbus • Action: Adduction • Nerve Supply: Oculomotor nerve Lateral Rectus • Origin: Annulus of Zinn • Insertion: 6.9mm behind the temporal limbus • Action: Abduction • Nerve Supply: Abducent nerve Anatomy Of The EOM’s Superior Rectus • • • • Origin: Annulus of Zinn Insertion: 7.7mm behind the superior limbus Action: Elevation, adduction and intorsion. Nerve Supply: Oculomotor nerve Inferior Rectus • Origin: Annulus of Zinn • • • Insertion: 6.5mm behind the inferior limbus Action: Depression, adduction and extorsion. Nerve Supply: Oculomotor nerve ANNULUS OF ZINN ANATOMY OF THE EOM’S Superior Oblique • • • • Origin: Superomedial to the optic foramen Insertion: Upper temporal quandrant of globe. Action: Intorsion, depression, abduction. Nerve Supply: Trochlear nerve Inferior Oblique • • • • Origin: Behind the orbital rim lateral to the lacrimal sac. Insertion: Lower temporal quadrant of globe. Action: Extorsion, elevation, abduction. Nerve Supply: Oculomotor nerve STRABISMUS • Misalignment of the visual axes of the two eyes • Classification – Pseudostrabismus – Heterophoria – Heterotropia • • Concomitant squint Incomitant squint PSEUDOSTRABISMUS • • • • Prominent epicanthal fold Hypertelorism No treatment required Tendency of the eyes to deviate when fusion is blocked. – – – – Esophoria (Inward imbalance) Exophoria (Outward imbalance) Hyperphoria (Upward imbalance) Hypophoria (Downward imbalance) HETEROTROPIA • • Manifest deviation in which the visual axes do not intersect at the point of fixation. – Esotropia (Inward deviation) Exotropia (Outward deviation) – – Hypertropia (Upward deviation) Hypotropia (Downward deviation) CONCOMITANT SQUINT • • The variability of the angle of deviation is within 5 Δ in different horizontal gaze positions. Angle of the deviation varies in various positions of the gaze as the result of abnormal innervation or restriction. SIGN and SYMPTOMS • • • • • • • Deviation of eye Loss of vision Eyeache / strain Diplopia Refractive errors Headache Head tilt ESOTROPIA • Classification: – Non accomodative • • • • • • • Infantile Esotropia Microtropia Near Esotropia Distance Esotropia Acute Esotropia Consecutive Esotropia Sensory Esotropia • ACCOMODATIVE 1. Refractive . fully accommodative . partially accommodative 2. Non-refractive . with convergence excess . with accommodation weakness 3. Mixed Esotropia • Infantile Esotropia – – – – – • Deviation within first six months of life with no significant refractive errors and no limitation of ocular movements. Angle is large (>30Δ) Fixation is alternating in primary position Cross fixation in side gaze Nystagmus Infantile Esotropia: – – – The refractive error is usually normal for the age of the child (about +1.50 D). Inferior oblique overaction may be present initially or develop later. Poor potential for BSV. ESOTROPIA • Refractive accommodative Esotropia – a physiological response to excessive hypermetropia and is beyond the patient's fusional divergence amplitude. – The deviation presents at about the age of 2.5 years, with a range of 6 months to 7 years. The two types are: Fully accommodative, which is completely eliminated by correction of the hypermetropic refractive error. Partially accommodative, which is only partially eliminated by correction of hypermetropia. ESOTROPIA • Non Refractive accommodative Esotropia – – – Associated with high AC/A ratio. Unit increased of accomodation accompanied by disproportionally large increase of convergence. The two types are: Convergence excess Accommodation weakness EXOTROPIA • • Constant – – – Congenital Sensory Consecutive Intermittent – – – divergence excess (worse for distance) convergence weakness (worse for near) basic exotropia (same for distance and near) STRABISMUS DIAGNOSIS • Patient History – – – – – – – – – – Probable time of onset of strabismus Nature of the onset (sudden or gradual) Frequency of deviation (constant or intermittent) Change in size or frequency of the deviation Which eye is strabismic Presence or absence of diplopia and other visual symptoms or signs History of neurologic, systemic, or developmental disorders Birth history Family history of strabismus Previous treatment, if any, and the type and results of such treatment. STRABISMUS DIAGNOSIS • OCULAR EXAMINATION – Visual Acquity – Light reflection tests – Cover test – Dissimilar image test – Binocular single vision test – Refraction – Fundoscopy STRABISMUS DIAGNOSIS – Visual Acquity: • • Testing in preverbal children – Fixation and following – Comparison between the behavior of two eyes. – Fixation behavior – Rotation Test – Preferential looking test – Pattern visual evoked potential Testing in verbal children – Crowded kays picture – Keeler logMAR – Sheridan Gardiner test – Sonkensen Crowded test STRABISMUS DIAGNOSIS – Light Reflection test • Hirshberg’s test – – – • Detect gross heterotropia Normal reflex » Just nasal to center of the pupil Abnormal reflex » » Border of the pupil (15deg or 30 prism D) » Limbus (45deg or 90 prism D) In between border and limbus (30 deg or 60 prism D) Krimsky’s Test – Place prism in front of deviated eye until light reflex is symmetrical Strabismus Diagnosis – Cover Tests • Cover-uncover test – Cover component » » » – Detects heterotropias Cover straight eye Look at uncovered deviated eye (movement indicate tropia) Uncover component » » » Detects heterophorias Uncover straight eye Look at uncover eye for deviation and refixation Strabismus Diagnosis – Alternate cover-uncover test • • • Detects heterophorias Alternate cover and uncover both eyes Look for uncover eye for movements – Alternate prism cover test • • Measures total deviation (tropias and phorias) Prism over deviated eye and alternate cover each eye until no movement Strabismus Diagnosis • Binocular Single Vision Test – Base out prism test – The Worth’s four dot test – Bagolini strilated glasses test – The synoptophore – Stereopsis tests • Titmus test , TNO, random dot, lang test and frisby plates STRABISMUS DIAGNOSIS • Refraction – – Cycloplegic refraction • • Paralysis of ciliary muscle to neutralize the affect of accommodation Drug used are Cyclopentolate and Atropine Fundoscopy • Exclude ocular pathology – Macular scarring – Optic disc hypoplasia – Retinoblastoma STRABISMUS TREATMENT – – Why we Treat • • • • Restore BSV Correct abnormal head posture Treat diplopia and confusion Correct misalignment Treatment options: • • • • Refraction correction Occlusion therapy Orthoptic exercises Prism in glasses • • Surgery Botulinum toxin chemodenervation STRABISMUS TREATMENT STRABISMUS TREATMENT • Surgery – Weakening procedures • Recession – – • • Slackens the muscle by moving it away from the insersion Disinserted muscle is sutured to the scalera behind its original insertion Disinsersion or myectomy – Detaching the muscle from its insertion without reattachment Posterior fixation sutures – Suture the muscle belly to the sclera posteriorly so as to decrease the pull of the muscle in its field of action STRABISMUS TREATMENT • STRENGTHENING PROCEDURES – Resection • Shortens the muscle to enhance to effective pull • • – – Sutures are tied into the muscle behind its insertion Muscle anterior to the suture is excised and the cut end is reattached to the original insertion Tucking • Tenden of superior oblique in congenital fourth nerve palsy Advancement • Muscle advancement nearer to the limbus.