Lecture Notes on Strabismus

Definition

• Strabismus: Misalignment of the eyes.
• Types:
  • Commotant Strabismus: Angle of deviation is the same in all gaze positions; extraocular movements are full.
  • Incomotant Strabismus: Angle of deviation varies with gaze position; extraocular movements are not full.

Causes and Implications of Incomotant Strabismus

• Restriction: Caused by ocular trauma, orbital inflammation, or orbital tumor.
• Paralysis: Due to improper cranial nerve innervation.
• Key Diagnoses:
  • Third Cranial Nerve Palsy:
    • Symptoms: Limited eye movements, droopy eyelid, eye in "down and out" position, possible dilated pupil.
    • Emergency: Possible brainstem aneurysm; requires immediate neuroimaging.
  • Sixth Cranial Nerve Palsy:
    • Symptoms: Interned eye (esotropia), limited abduction, possibly associated with disc swelling (papilledema).
    • Emergency: Must rule out raised intracranial pressure; requires neuroimaging.

Pediatric Considerations

• Strabismus and Amblyopia: Can indicate serious eye problems in children.
• Serious Conditions:
  • Retinoblastoma:
    • Description: White tumor of the retina.
    • Consequences: Blindness, loss of eye, death if untreated.
  • Congenital Cataract:
    • Consequence: Blindness if not treated urgently.

Screening and Diagnosis

• Red Reflex Examination:
  • Conducted with a direct ophthalmoscope during routine checkups from birth.
  • Normal Red Reflex: Indicates no obstruction.
  • Dark/White Reflex: May suggest retinoblastoma or congenital cataract; requires immediate referral to ophthalmology.