pupil examination step by step for ophthalmic exam.pptx

can help you with pupil abnormalities

1. Pupil By Staff Members Ophthalmology Department Zagazig University 2022

2. I am Dr Ahmed Elsayed Assistant lecturer of Ophthalmology / Zagazig University And You ? Group A7

3. Rules

4. PUPILLARY LIGHT REFLEX Definition : When light falls on one eye, pupil of this eye become smaller (Direct light reflex) and also pupil of the other eye (Indirect, consensual or crossed light reflex).

5. Pathway of pupillary light reflex : Stimulus : light. Receptors : Rods and cones in the retina. Afferent : Axons of ganglion cells → Optic nerve → Chiasma → In the chiasma, the nasal fibers cross to reach the optic tract of the opposite side (First crossing). The temporal fibers pass directly into the optic tract of the same side. → Fibers leave tract at its posterior third → Mid-brain and relay in the pre-tectal nucleus → Edinger-Westphal nucleus on both sides (Second crossing).

6. Centre: Edinger-Westphal nucleus (Part of III nerve nucleus). Efferent : III nerve with parasympathetic fibers → Ciliary ganglion → Post ganglionic fibers enter the eye (in short ciliary nerves) to supply sphincter pupille muscle. N.B: Consensual reaction is due to crossing of the fibers in the Chiasma and in Midbrain. N.B: Consensual reaction is due to crossing of the fibers in the Chiasma and in Midbrain.

7.   Technique of pupillary light reaction The illumination room is reduced and, the patient should be instructed to look at a distant object to reduce accommodation and bright light is directed on the side of the patient’s eye (Avoid standing in front of the patient or placing the light in the front of the eye, this will stimulate accommodation and hence miosis ). Placing the light on side of one eye gives direct pupillary light reaction (Constriction of the pupil) in this eye and consensual pupillary light reaction (Constriction of the pupil) in the other eye.

8.   Technique of pupillary light reaction Repeat in other eye. Movement of the light to and fro between the eyes gives Swinging flashlight test (Constriction of both pupil). If one pupil dilates instead of constricts, this is an afferent pupil defect indicating a serious retinal or optic nerve problem.

9. Group interaction

10. Check list Reduction of room illumination the patient should be instructed to look at a distant object to reduce accommodation Bright light is directed on the side of the patient’s eye while observing the size of the patient’s pupil Repeat the test in other eye Swinging flashlight by moving the light to and fro between both eyes Interpretation of the result  

11. NEAR REACTION When a near object is viewed, three related reflexes occur : Convergence, by contraction of the two medial recti muscle. Miosis, by contraction of the sphincter pupillae muscle. Accommodation, by contraction of ciliary muscle. All three reflexes are mediated by III nerve.

12. Technique of a ccommodation (near response) test Ask the patient to look from the distance fixation to near object, both pupils should constrict equally.

13. Pathway : Stimulus : Blurring of the image. Receptors: Rods and cones. Afferent : Rods and cones → Optic nerve → Chiasma → Optic tract → Lateral geniculate body → Optic radiation → Occipital cortex → Frontal cortex → internal capsule → Edinger Westphal nucleus. Centre : Edinger Westphal nucleus. Efferent: Same as in the light reflex.

14. ABNORMAL PUPILLARY REACTION Relative afferent pupillary defect (RAPD, Marcus Gunn pupil) : It is a sign caused by unilateral : a- Partial optic nerve lesion. b- Severe retinal disease.

15. b- “Swinging flashlight test” : When swinging the light from the unaffected to the affected eye , the abnormal pupil dilates instead of constricting. It is characterized by : a- Vision in the affected eye is markedly diminished while vision in the another eye is normal.

16. It is characterized by : Involved eye is completely blind (NO PL). Loss of direct and consensual reaction on stimulation of the affected eye while both reactions are intact on stimulation of the normal eye. Near reflex is normal in both eyes. Absolute afferent pupillary defect (amaurotic pupil) : It is caused by a complete optic nerve lesion or central retinal artery occlusion.

17. Questions Dr : Ahmed Elsayed Mohamed [email protected] 00201147110558