Disorders of Pupil Reactions

Lecture Outline

  • Lecture Objectives

  • Pupil reaction abnormalities:

  1. Efferent Disorders

  2. Afferent Disorders

  • Summary

Lecture Objectives

  • Discuss abnormal pupil reactions, their presentation, and workup.

Abnormalities of Pupil Reactions

  • ICD-10 Codes: H57.0XY - Anomalies of Pupillary Function

Terminology

  • Miosis (H57.03): Constriction (small pupil)

  • Mydriasis (H57.04): Dilation (large pupil)

  • Anisocoria (H57.02): Unequal pupil size

Pupil Reaction Testing

  • Methods of assessment:

  • Room illumination

  • Direct/consensual light tests

  • Light reflex comparisons

  • Near targets assessment

  • Normal response is PERRLA (Pupils Equal, Round, Reactive to Light and Accommodation)

Types of Pupil Reaction Abnormalities

  1. Efferent disorders affecting motor output:

  • Parasympathetic and sympathetic innervation issues

  1. Afferent disorders affecting sensory input:

  • Light and near input failures

  1. Drug effects:

  • Impact of drugs like cocaine, amphetamines

Light Pathways: Afferent (to CNS)

  • Visual pathway from retina to visual cortex depicted (e.g. Left/Right Retina, Left/Right Striate Cortex)

Pupillary Pathways : Efferent (from CNS)

  • Efferent pathways for Near Reflex and Light Reflex explained

Abnormalities to Test For

  1. Marcus Gunn Pupil (RAPD)

  • Active dilation during flashlight test

  1. Argyll Robertson pupil

  • Bilateral miosis; reacts better to near stimulus

  1. Adie’s Tonic Pupil

  • Unilateral mydriasis, poor light response, more common in females

  1. Horner’s Syndrome

  • Miosis, ptosis, and anhydrosis triad

  1. Hutchinson Pupil

  • Unilateral fixed and dilated; indicates CN III lesion

  1. Pharmacological Pupil

  • Effects of mydriatic/miotic agents (e.g. atropine, pilocarpine)

Detailed Assessment of Abnormalities

1. Marcus Gunn Pupil

  • Assess through swinging flashlight test

2. Argyll-Robertson Pupil

  • Causes include sarcoidosis, diabetes; light-near dissociation

3. Adie’s Tonic Pupil

  • Associated with viral infection, typically benign

4. Horner’s Syndrome

  • Triad: Miosis, ptosis, anhydrosis - examine causes for lesions

  • Special tests: Cocaine and apraclonidine tests used for diagnosis

5. Hutchinson Pupil

  • Usually post-head trauma or other serious conditions

6. Pharmacological Pupils

  • Various drugs can affect pupil size and reaction

Summary

  • Important to understand anatomy for interpreting pupil reaction abnormalities

  • Required thought process: Is it efferent, afferent, or drug-related?

Further Reading

  • Bowling, B. (2016). Kanski's clinical ophthalmology: A systematic approach (8th ed.).

  • Gerstenblith, A., & Rabinowitz, M. (2012). Wills Eye Manual: Office and Emergency Room Diagnosis and Treatment of Eye Disease (6th ed.).