A Comparison of Near Strabismus Measurements with Different Fixation Targets

Abstract

Background and purpose: It has been reported there is a difference in the size of esodeviations when using letters compared to pictures or lights as a fixation target. In many clinics, small picture stickers are used as a target for preliterate or uncooperative children. In this study, experimental stickers with detailed pictures were compared to the Lang fixation cube and a monochromatic circle to assess their suitability as near fixation targets for the measurement of near deviations.

Patients and methods: Participants were 3-5 years of age and had an esodeviation. The near angle of deviation was measured using the three targets and compared to determine if treatment would be affected. Clinical significance is based on a difference of 5 prism diopters (PD) as this could potentially change the treatment plan.

Results: The results of the study show no clinically significant difference when comparing the three near targets. The experimental sticker induced the most accommodation, followed by the Lang fixation cube and then the red circle sticker.

Conclusion: Although none of the mean differences between the target comparisons reached the clinically significant threshold set, it should be considered that over one third of participants had a clinically significant difference in the esodeviation measurement at 33 cm when using the detailed picture sticker when compared to the red circle sticker.

Keywords: Esodeviation; fixation target; preliterate; strabismus measurement.