Sign Up for a Free Account

This is an image preview.
Start a Free Account
to view the full image.

  • Nearly 3,000 illustrations, including video clips of neurologic disorders.

  • Every article is reviewed by our esteemed Editorial Board for accuracy and currency.

  • Full spectrum of neurology in 1,200 comprehensive articles.

Single Maddox rod test measuring vertical ocular misalignment

Single Maddox rod test: measuring vertical ocular misalignment in patient with right fourth and sixth cranial nerve palsies. (A) Maddox rod is placed in front of right eye with cylinders stacked horizontally as patient views a bright light (not shown in this frame). (B) Patient sees a horizontal red line (with right eye) that is displaced below the light, indicating a right hyperdeviation. (C) Vertical prism bar is placed base-down in front of Maddox rod and positioned such that the patient reports that the horizontal red line has moved upward so that it now appears to the patient to pass through the fixation light. (D) The amount of prism-diopters (read off the prism bar) necessary to bring the light into this position is the measure of the degree of right hyperdeviation. (Contributed by Dr. Kara Warden.)

Related Media

Associated Disorders

  • Anxiety
  • Blunt trauma to the orbit
  • Botulism
  • Brainstem tumors
  • Combined extraocular cranial nerve palsies
  • Encephalitis
  • Esotropia
  • Exotropia
  • Fourth cranial nerve palsy
  • Genetic extraocular myopathies
  • Graves disease
  • Idiopathic orbital inflammation
  • Illusory spread
  • Increased intracranial pressure
  • Internuclear ophthalmoplegia
  • Lambert-Eaton myasthenic syndrome
  • Malingering
  • Meningitis
  • Midbrain lesion
  • Myasthenia gravis
  • Neoplastic infiltration of the extraocular muscles
  • Ocular motor cranial nerve palsy
  • Palinopsia
  • Sixth cranial nerve palsy
  • Skew deviation
  • Superior oblique tendon sheath (Brown) syndrome
  • Third cranial nerve palsy
  • Visual hallucinations