You are in: eMedicine Specialties > Ophthalmology > EXTRAOCULAR MUSCLES Exotropia, PseudoArticle Last Updated: May 18, 2006AUTHOR AND EDITOR INFORMATIONSection 1 of 8
  Author: Kalpana K Jatla, MD, Fellow in Glaucoma, Department of Ophthalmology, Wills Eye Hospital Kalpana K Jatla is a member of the following medical societies: American Academy of Ophthalmology Coauthor(s): S Anna Kao, MD, Staff Physician, Department of Ophthalmology, West Georgia Medical Center; Kenneth T Horlander, MD, Consulting Staff, Department of Pulmonary and Critical Care Medicine, West Georgia Health System; Robert William Enzenauer, MD, MPH, Professor, Department of Ophthalmology, Hamilton Eye Institute, University of Tennessee Health Science Center Editors: Gerhard W Cibis, MD, Clinical Professor, Director of Pediatric Ophthalmology Service, Department of Ophthalmology, University of Kansas, Kansas City; Simon K Law, MD, PharmD, Assistant Professor of Ophthalmology, Jules Stein Eye Institute; Chief of Section of Ophthalmology Surgical Services, Department of Veterans Affairs Healthcare Center, West Los Angeles; J James Rowsey, MD, Former Director of Corneal Services, St Luke's Cataract and Laser Institute, Florida; Lance L Brown, OD, MD, Ophthalmologist, Affiliated With Freeman Hospital and St John's Hospital, Regional Eye Center, Joplin, Missouri; Hampton Roy Sr, MD, Associate Clinical Professor, Department of Ophthalmology, University of Arkansas for Medical Sciences Author and Editor Disclosure Synonyms and related keywords: pseudostrabismus, pseudoexotropia INTRODUCTIONSection 2 of 8
  BackgroundPseudoexotropia is a condition in which the alignment of the eyes is straight (also known as orthotropic); however, they appear to be turned outward. PathophysiologyPseudoexotropia occurs with a wide interpupillary distance or a positive angle kappa. Angle kappa is the angle formed between 2 imaginary lines: the visual axis and the pupillary axis. To construct the visual axis, extend a straight line from the viewing object through the nodal point. A straight line going through the center of the pupil and perpendicular to the corneal plane constructs the pupillary axis. Since fovea is displaced temporally, a small angle kappa (up to 5°) manifests as a nasally displaced corneal light reflex. Children may falsely appear to have an exotropia when they look to the side. FrequencyUnited StatesIncidence is higher in children with a temporally dragged macula from retinopathy of prematurity. SexNo known sexual predilection exists. AgeAppearance is seen at any age. CLINICALSection 3 of 8
HistoryParents bring their child to their physician, reporting that the child's eyes appear to be turned out. PhysicalPatients appear to have a large angle kappa or nasally deviated corneal light reflex. By performing the cover-uncover test, no movement can be demonstrated. In the case of a dragged macula, an ophthalmoscope examination reveals an ectopic macula displaced temporally. CausesA common cause of pseudoexotropia is a dragged or temporally displaced macula associated with retinopathy of prematurity. Retinal scarring in the temporal periphery caused by Toxocara canis is another cause of a temporally displaced macula resulting in pseudoexotropia. DIFFERENTIALSSection 4 of 8
Exotropia, Acquired Exotropia, Congenital WORKUPSection 5 of 8
Other Tests
TREATMENTSection 6 of 8
Medical CareNo treatment is indicated for this condition. ConsultationsPatients with suspected pseudoexotropia initially should be examined and then observed by an ophthalmologist because true tropia or true exotropia may later develop. For example, a large positive angle kappa may hide an esodeviation, and a negative angle kappa may hide an exodeviation. FOLLOW-UPSection 7 of 8
Further Outpatient Care
Patient Education
REFERENCESSection 8 of 8
Article Last Updated: May 18, 2006 |
