Vergence Pathway

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    • Brain pathway that initiates convergence eye movements
    • Tip: divergence eye movements may occur by relaxation of convergence
    • Adjusts the position of the eyes to maintain bifoveal fixation as the visual target moves closer or farther away from the viewer
    • Signal travels to the occipital cortex in both cerebral hemispheres, which activates or inhibits convergence to avoid diplopia
    • From the visual cortex, the signal goes to a tegmental midbrain (vergence) area to initiate convergence
    • Lesion of the afferent visual pathway
      • Produces reduced vision, which breaks fusion and causes comitant esotropia
        or exotropia
        (“sensory ocular misalignment”), but retains full amplitude of ocular ductions
      • Common cause: any lesion of the visual pathway
    • Lesion of the descending cerebral pathways from the occipital lobes on both sides
      • Impairs transmission from the occipital lobes to the brainstem vergence center, which breaks fusion and causes comitant esotropia
        or exotropia,
        but retains full amplitude of ocular ductions
      • Common causes: head trauma, encephalitis, narcotic or other neurotropic medication or drug use, sleep disturbance, fever, and increased intracranial pressure
    • Lesion of the thalamus or midbrain
      • Disrupts the brainstem vergence center and causes comitant esotropia
        or exotropia,
        but retains full amplitude of ocular ductions
      • Tip: with a suspected thalamic or midbrain lesion, expect to find one or more of these clinical abnormalities
        • Impaired vertical gaze
        • Skew deviation
        • Lid retraction
        • Impaired pupil constriction to light with or without light-near dissociation (tectal pupils)
        • Third nerve palsy
        • Fourth nerve palsy

    Supranuclear Ocular Motor Pathways

    Overview Videos Horizontal Saccades Vertical Saccades Pursuit Pathway Vergence Pathway Vestibulo-Ocular Reflex