The validity and repeatability of the New Aniseikonia Test.

Abstract

PURPOSE:

Aniseikonia has been traditionally measured using the New Aniseikonia Test (NAT) based on red/green anaglyphs. This study was designed to establish whether the NAT is a valid and reliable test.

METHODS:

The NAT was tested on three groups of subjects: a control group (n = 45) and two groups of participants at risk of experiencing aniseikonia, those with anisometropia greater than or equal to 1.00 D (n = 29) and those with bilateral pseudophakia (n = 26). The validity of the test was established by comparing the measured aniseikonia with that simulated with size lenses in a double-blind study. Repeatability was evaluated by comparing the results obtained at two different time points.

RESULTS:

Our results indicate that the NAT underestimates aniseikonia and more so in the horizontal than in the vertical direction. Repeatability was poor, although biases were clinically insignificant. However, the 95% limits of agreement were around +/-2%. The behavior of the test was similar in the three groups of subjects.

CONCLUSIONS:

We conclude that the repeatability of the NAT is not very high and recommend that clinicians be cautious when interpreting the results of this test.

• Authors: Beatriz Antona, Francisco Barra, Ana Barrio, Enrique Gonzalez, Isabel Sánchez
• Journal: Optometry and vision science : official publication of the American Academy of Optometry (Optom Vis Sci) Vol. 83 Issue 12 Pg. 903-9 (Dec 2006) ISSN: 1040-5488 [Print] United States
• PMID: 17164683 (Publication Type: Journal Article, Multicenter Study, Research Support, Non-U.S. Gov't, Validation Study)

Topics

• Adult
• Aniseikonia (diagnosis, physiopathology)
• Humans
• Refraction, Ocular (physiology)
• Reproducibility of Results
• Vision Tests (standards)
• Vision, Binocular (physiology)