J Korean Ophthalmol Soc.  2009 Feb;50(2):269-274. 10.3341/jkos.2009.50.2.269.

10-Prism-Diopter Fixation Test for Amblyopia

• Park JY
• Park SH

• KMID: 2212061
• DOI: http://doi.org/10.3341/jkos.2009.50.2.269

Abstract

PURPOSE: To evaluate the clinical usefulness of the 10-prism-diopter (PD) fixation test in the diagnosis of amblyopia.
METHODS
The study comprised 132 children (42 normal, 90 amblyopes) who underwent the 10-PD fixation test and stereoacuity test. The sensitivity, specificity, false-positive and false-negative rates of the 10-PD fixation test were analyzed according to the clinical diagnosis.
RESULTS
The 10-PD fixation test sensitivity was 86%, the specificity was 61%, the false-positive rate was 17% and the false-negative rate was 24%. Data showed agreement between the 10-PD fixation test and the stereoacuity test (gamma=0.737, p=0.000). The results in the 10-PD base-down test and base-out test also showed agreement (gamma=0.779, p=0.000).
CONCLUSIONS
The 10-PD fixation test is a simple and useful method in detecting amblyopia.

Keyword

Amblyopia; 10 prism diopter fixation test

MeSH Terms

Amblyopia
Child
Humans
Sensitivity and Specificity

Figure

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  Figure 1. Responses to 10-PD base-out test. We regarded A and B as positive response that means equal fixation preference, C and D as negative response or suppression. (A) Non fixating eye (right eye) makes convergence and left eye maintain fixation while also converging. (B) Both eyes make version movement to the opposite side on which the prism was placed, followed by a convergence to the fixation target. (C) Version movement of both eyes, with no convergence. (D) No movement of either eye.

Reference

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