Rapd

RAMJI PANDEY
SENIOR CONSULTANT OPTOMETRIST
[email protected]

1. PUPILLARY EVALUATION -DIRECT & CONSENSUAL LIGHT REFLEX, NEAR REFLEX TEST, ASSESSMENT OF RAPD PRESENTER-RAMJI PANDEY SENIOR CONSULTANT OPTOMETRIST 1

2. Anatomy of pupil Pupil is a aperture located in a center of the iris of the eye that allows light to strike the retina. Iris consists mainly of smooth muscle, a circular group called the sphincter pupillae and a radial group called the dilater pupillae . When sphincter pupillae contract the pupil decreases or constrict the size The dilater pupillae innervated by sympathetic nerves from the superior cervical ganglion, cause the pupil to dilate when they contract of pupil. 2

3. FUNCTION OF THE PUPIL Functions :  Control in retinal Illumination  Reduction in optical aberration Clinical Importance Objective indicator of Light Input Anisocoria Pharmacological Indicator Indicator of level of wakefulness 4

4. VISUAL PATHWAY Visual pathway or Optic Pathway is the nervous pathway that transmits impulses from retina to visual center in cerebral cortex Components • Optic Nerve • Optic Chiasma • Optic Tract • Lateral Geniculate Bodies • Optic Radiations • Visual Cortex 5

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6. Nasal Fibers decussate in optic chiasma Optic tract Travels centrally along the optic nerve Gang li o n cells Rod s an d c ones

7. The Ac c e s s o ry motor nu c lei o f E W nucleus N e w r e l a y fi be rs p a rti a l l y cr o ss ov e r Prete c tal Nu cl eus Midbrain from Lateral side of Superior colliculus

8. Located inferiorly as it enters the orbit The axons of the EW nucleus extend into the III nerve Lie on the superficial dorsomedial aspect as it leave the brain stem Passes laterally to petroclinod ligament and dorsum sellae

9. Inferior division of III nerve Ciliary Gangli o n Via short Ciliary nerves Sphincter Pupillae

10. THE LIGHT REFLEX The light reflex consist of simultaneous and equal constriction of pupils in response to stimulation of one eye by light Constriction is elicited with extremely low intensities and is proportional within limits to both intensities and duration of stimulus . 11

11. LIGHT REFLEX When light is shone in one eye both the pupils constricts. Two Types: Direct Light Reflex Indirect (Consensual) Light Reflex Constriction of pupil to which light is shone : Direct Light Reflex and that of other : Indirect Light Reflex 12

12. EXAMINATION OF PUPILLARY REFLEX Direct Light Reflex Normal pupil reacts briskly & its constriction to light is well maintained Consensual Light Reflex Normally contralateral pupil should also constrict when light is thrown on to one pupil 13

13. LIGHT REFLEX TEST What it assess- the integrity of the pupillary light reflex pathway. How to perform it- dim the ambient light and the ask the patient to fixate a distant target. Shine the right eye from right side and left eye from left side.(Make sure you do not stand infront of the patient as their pupils will accommodate to focus on you). Record whether there is a direct pupillary response (the pupil constricts when the light is shone on it) and a consensual response (the fellow pupil constricts too). Normal test- there should be a brisk, simultaneous ,equal response of both pupils in response to light shone in one or the other eye. 14

14. NEAR REFLEX Two components: 1. Convergence Reflex: Convergence of visual axis and associated constriction of pupil 2. Accommodation Reflex: Increased accommodation and associated constriction of pupil Near Reflex Traid consists of: - Increased Accommodation - Convergence of Visual Axis - Constriction of pupils 15

15. Fibers form Medial Rectus m. via III n. M e s en c ephali c n . o f V ner v e Convergence Center in Tectal or Pre Tectal Region EW N u c leus Efferent fibers travel along III nerve R ela y i n Acc e ss or y Ganglion Sphinc t e r Pupillae

16. Retina Via Optic nerve, Chaisma Optic Tract Lateral Geniculate Body,optic radiation Striate Cortex From the Para Striate Cortex Via Occipitomesencephalic Tract and Pontine center EW Nucleus Via III nerve to Sphincter Pupillae

17. NEAR REFLEX TEST Instruct the patient to look at the distant target The examiner holds up a target containing fine detail approximately 25cm from the patient Ask the patient to fixate the near target and look for pupil constriction Note the speed of the constriction and the roundness of each pupil 18

18. AFFERENT PUPILLARY DEFECTS Assessment of afferent input from the retina, optic nerve, and chiasma , optic tract and midbrain till LGB Damage anywhere along this portion of the visual pathway reduces the amplitude of pupil movement in response to a light stimulus TOTAL AFFERENT PUPILLARY DEFECT 19 Absence of Direct light reflex on affected side and absence of consensual light reflex on normal side When the normal is stimulated both pupils react normally Diffuse illumination both pupils are equal in size Near reflex is normal in both eyes

19. RAPD (Relative Afferent Pupillary Defect) Paradoxical response Marcus Gunn pupil RAPD cause a reduction in pupil contraction when one eye is stimulated by light compared with when the opposite eye is stimulated by light. 20

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21. GRADING SCALE: RAPD Grade 1+: A weak initial pupillary constriction followed by greater redilation Grade 2+: An initial pupillary stall followed by greater redilation Grade 3+: An immediate pupillary dilation Grade 4+: No reaction to light – Amaurotic pupil 22

22. Causes of RAPD Optic neuritis Anterior ischemic optic neuropathy Compressive optic neuropathy Glaucoma Optic Nerve Tumors Orbital Diseases Ischemic Retinal Diseases : CRAO CRVO BRAO BRVO Ocular Ischemic Syndrome CSCR or CME RD Chiasmal compression  Optic tract lesion  Postgeniculate damage  Midbrain tectal damage 23

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