Pupil Exams and Visual Fields A Closer Look at Cranial Nerves No Financial Interests Amy Jost does not have any financial interests related to this presentation AMY JOST, BS, COMT, CCRC, OSC CINCINNATI EYE INSTITUTE Objectives Identify correlation between cranial nerves and the affects on muscles, pupils, and lids Differentiate between afferent and efferent messages from the eye to the brain. Discuss EOM Testing, Pupil Assessments, Ptosis Measurements, and Visual Field Testing List of the Cranial Nerves I. Olfactory (Smell) II. Optic (Sight) III. Oculomotor (Moves eyelid and eyeball and adjusts the pupil and lens of the eye) IV. Trochlear (Moves eyeballs) V. Trigeminal (Facial muscles incl. chewing; Facial sensations) VI. Abducens (Moves eyeballs) VII. Facial (Taste, tears, saliva, facial expressions) VIII. Vestibulocochlear (Auditory) IX. Glossopharyngeal (Swallowing, saliva, taste) X. Vagus (Control of PNS e.g. smooth muscles of GI tract) XI. Accessory (Moving head & shoulders, swallowing) XII. Hypoglossal (Tongue muscles - speech & swallowing) Cranial Nerves and Ocular Function Cranial Nerve II, Optic Nerve Cranial Nerve III, Oculomotor Nerve Cranial Nerve V 1, Ophthalmic Nerve (sensory) Cranial Nerve IV, Trochlear Nerve Cranial Nerve VI, Abducens Nerve 1
Muscle Insertions Extraocular Muscles Brain Extraocular Muscles LR6, SO4, all the rest are 3 Superior Oblique CN IV Inferior Rectus CN III Medial rectus Inferior Oblique, CN III Lens Medial Rectus CN III Superior Rectus CN III Lateral Rectus CN VI Primary Function and Innervation Muscle Primary Function Innervating Nerve Medial rectus Nasal (adduction) CN III (Oculomotor Nerve) Secondary and Tertiary Functions Muscle Secondary Function Tertiary Function Medial rectus None None Lateral rectus Temporal (abduction) CN VI (Abducens Nerve) Superior rectus Upward (elevation) CN III (Oculomotor Nerve) Inferior rectus Downward (depression) CN III (Oculomotor Nerve) Lateral rectus None None Superior rectus Incyclotorsion Nasal (adduction) Inferior rectus Excyclotorsion Nasal (adduction) Superior oblique Rotates towards the nose (incyclotorsion) CN IV (Trochlear Nerve) Superior oblique Downward (depression) Temporal (abduction) Inferior oblique Rotates away from the nose (excyclotorsion) CN III (Oculomotor Nerve) Inferior oblique Upward (elevation) Temporal (abduction) Cranial Nerves specific to EOM ocranial Nerve III, Oculomotor Nerve ocranial Nerve IV, Trochlear Nerve ocranial Nerve VI, Abducens Nerve Understanding 3 rd Nerve Palsy Knowing what CN III innervates, makes it easer to understand what it affects Down and Out 2
Cranial Nerve III Oculomotor Nerve innervates SR, IR, MR, IO Innervates Levator palpebrae muscle (lifts the lids) Also Innervates iris sphincter muscle and ciliary body, affecting pupil size and near vision 3 rd Nerve Palsy Effects on the EOMs Medial Rectus (Reduced adduction/turn towards nose) Superior Rectus (Reduced elevation/upward movement) Inferior Rectus (reduced depression/downward movement) Inferior Oblique (reduced excylotorsion) 3 rd Nerve Palsy- Left Eye OS municating artery 3 rd Nerve Palsy Effects on Accommodation c Decreases Ciliaris Muscle function, affects ability to accommodate Decreased Near Vision 3
3 rd Nerve Palsy Causes Anisocoria Decreases sphincter Pupilae (iris sphincter) function Difference in pupil size due to mydriasis of affected eye Worse in bright light, affected pupil will not constrict Pupil Assessments Pupil Reaction Reacts to Light Reacts to Accommodation Reacts to excitement/adrenaline rush Reacts to medications Pupillary Assessment Watching Pupils, but really assessing functionality of the retina/optic nerve If retina not functioning, photoreceptors cannot properly detect light If Optic Nerve not functioning, cannot carry the message to the brain Pupil size Measure pupil size in dim light and in bright light in BOTH eyes Pupil Shape Regular (round) vs. Irregular 4
Direct and Consensual Response RELATIVE Afferent Pupillary Defect Shine light into the Right eye, RIGHT pupil constricts= Direct Reaction Shine light into the Right eye, LEFT pupil constricts= Consensual Reaction Relative (as compared one to the other) If there are equal in health or damage, there is no relative difference If there is no difference between the two eyes, there will be no RAPD Afferent and Efferent Pathways Afferent: From an organ (eye) to the Brain Efferent: From the Brain back to the Organ (BOTH eyes) Give example Swinging Flashlight Test Shine light into one eye, note pupil reaction BOTH eyes should constrict due to direct and consensual response Quickly switch the light over to the Fellow Eye (if both eyes are normal, pupils should NOT constrict/dilate) Because pupils already constricted Swinging Flashlight Test Relative Afferent Pupillary Defect (R-APD) If pupil constricts further, that eye is likely normal If pupil dilates, that eye has an APD 5
Ptosis Measurements Eyelid Assessments Distance between Corneal Reflex and Eyelid Margin Graded MRD in mm of droop: Mild ptosis: 2 mm Moderate ptosis: 3 mm Severe ptosis: 4 mm Also presents with: Ptosis Anisocoria In light Which eye is affected? In dark Anisocoria due to Miosis of affected eye, worse in dark Ptosis in affected eye Anhydrosis (no sweating on half of face/head) Can be caused by carotid artery damage/neck injury Adie s Tonic Pupil Anisocoria Affected pupil is larger with bright light reflex Pupil may react to Accommodation Muscle function/pupils NOT affected Limited reaction to light in affected eye Reacts (constricts) with accommodation 6
ADIE S TONIC PUPIL Visual Field Assessments Affected eye will constrict MORE than the normal eye Criss-Cross &Upside Down All things on the Right Side, go to the Left side of the brain All things Superiorly, are seen on the inferior side Visual Field Fun Facts Damage before the Chiasm, defect will be in ONE eye Damage at or beyond the Chiasm, Defect will be similar in BOTH eyes Visual Field Fun Facts Look at these defects Types of Visual Fields Amsler Grid Confrontation Visual Field Humphrey Visual Field Goldmann Visual Field Tangent Screen 7
Kinetic vs. Static Visual Fields Kinetic VF: Target stimulus is slowly moved from the non-seeing area of the visual field into the visual field until detected by the patient (Goldmann VF, Tangent Screen, can do CVF) Static VF: Target is presented suddenly, then disappears, no movement of the target (HVF, CVF) Tips on Performing HVF Patient Education is Key! There is a learning curve Fixation Set the lenses correctly: Correct power, Axis, distance from the eye Retinal Nerve Fiber Layers Arcuate Scotomas Visual Field Parameters Temporally, 100-110 Nasally, 60 Visual Field Parameters Superiorly, 50-60 Inferiorly, 70 Tips on Performing CVF Check centrally and in the Four Corners Avoid the Horizontal and the vertical meridians Extend fully Temporally. Go alllllthe way out Nasally not as far Inferiorly, further than Superior Let s try this 8
Amsler Grid Central 20-30 May Identify Macular Pathology Like a Near Vision test Need reading Rx well Lit chart Proper Distance Visual Field Vocabulary Scotomas Depressions Constricted Hemianopia Quadrantanopia Temporal Nasal Altitudinal Arcuate Central Cecocentral/Paracentral Congruous Homonymous Blind Spot Macular Sparing RNFL C/D ratio Horizontal Raphe CVF/HVF/GVF/Octopus Amsler Grid Kinetic Perimetry Static Perimetry SITA Apostilbs Fixation Losses False Positives False Negatives Stimulus Threshold Isopters Island of Vision Nasal Step Pie in the Sky Any Questions? Amy Jost Cincinnati Eye Institute Research & Education Department 1945 CEI Drive Cincinnati, OH 45242 513-569-3678 ajost@cincinnatieye.com 9