-IBIS-1.5.0-
tx
eyes/ears/nose/throat
strabismus
diagnoses

definition and etiology

definition:
direction of the eyes deviates from a normal parallel orientation;
• paralytic (noncomitant)
• nonparalytic (comitant or concomitant)

etiology:
• paralytic: may follow defects in oculomotor nuclei, nerves or muscles; may be caused by CNS, thyroid, muscle diseases, congenital abnormalities, trauma, neoplasm, infection
• nonparalytic: muscles function but do not properly converge; may follow vision problems, especially pediatric hyperopia
• some physicians have noted mild strabismus associated with anxiety states in young people, particularly in anorexic/bulimic types

signs and symptoms

signs and symptoms:

• paralytic: gaze remains parallel except when action of paralyzed muscle is demanded; diplopia will occur at that time
• non-paralytic, concomitant: convergent: usual onset under 5 years old; child corrects diplopia suppressing the image from one eye, creating risk of amblyopia
• non-paralytic, concomitant: divergent: absence of diplopia, eyes are used individually to fix objects in gaze; normally intermittent
• non-paralytic, comitant: latent: follows fatigue or illness in child, which breaks down intent to keep eyes parallel

course and prognosis

• paralytic: course depends on underlying cause; surgery sometimes helpful
• convergent: usually resolves with vision correction where this is the underlying problem; surgery may be necessary if this fails; amblyopia may persist in children treated too late
• divergent: usually resolves with surgery, which is the conventional treatment
• latent: orthoptic exercises, visual correction, surgery will usually correct this, depending on severity

differential diagnosis

• determine cause


footnotes