Pseudoexotropia

Updated: May 12, 2021
  • Author: Barbara L Roque, MD, DPBO, FPAO; Chief Editor: Donny W Suh, MD, FAAP  more...
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Overview

Practice Essentials

Pseudoexotropia is a clinically stable condition associated with a positive angle kappa due to macular ectopia. It can be identified early but should be monitored regularly, as a small percentage of cases could develop true strabismus. Parents should be counseled to focus on preventing further macular damage rather than fixing cosmetic appearance. Risk factors include prematurity, high myopia, and chorioretinal infection.

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Background

The term pseudoexotropia refers to an apparent outward deviation despite the eyes being well-aligned. [1]   

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Pathophysiology

Pseudoexotropia presents 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. The visual axis is the line connecting the fixation point with the fovea while the pupillary axis is the line that perpendicularly passes through the entrance pupil and the center of curvature of the cornea.  

Because the fovea is displaced temporally in cases with macular dragging (such as in cicatricial retinopathy of prematurity [2] ), positive angle kappa manifests as a nasally displaced corneal light reflex, and translates into a clinical disparity between the prism cover tests and the Hirschberg measurements.  

 

 

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Epidemiology

Frequency

United States

The incidence of pseudoexotropia is higher in children with a temporally dragged macula from retinopathy of prematurity.

Sex

No known sexual predilection exists.

Age

The appearance of pseudoexotropia is seen at any age.

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Prognosis

The degree of pseudoexotropia is usually stable as long as the associated macular dragging is also stable. In a retrospective review of 65 cases initially diagnosed with pseudostrabismus, 8 patients (12%) developed true strabismus. [3] One of the 8 developed true exotropia while the rest developed true esotropia.4 Risk factors were binocular single vision and the best corrected visual acuity. [3]  In cases with associated pattern strabismus, they can be successfully operated on to address the pattern, without making the pseudoexotropia worse. [4]  

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Patient Education

Parents should be counseled to focus on preventing further macular damage rather than fixing cosmetic appearance.

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