Differences in the values of anaglyphs, vectograms and cheiroscopes on participants with low, normal, and high AC/A ratio

Abstract

Purpose: Anaglyphs, Vectograms and Cheiroscopes are visual therapy materials based on red/green, polarized, or black/white targes that used similar but slightly different images for each eye to train fusion and vergence skills. This study aimed to analyse the differences in the results obtained on those devices on participants with low, normal, or high AC/A ratios. Material and methods: three groups of volunteer participants were recruited based on their recent clinical history among patients attending the Optometry Clinic of the centre: 15 participants with low AC/A, 15 participants with normal AC/A and 15 participants with High AC/A ratios. None of them was under any type of medication, have an ocular or systemic disease, or were performing any kind of visual training plan that could affect the study. In two sessions one week apart, following the manufacturer's instructions, the participants performed in a random order three visual therapy device-based training: one red/green Fixed Demand Anaglyph [FDA], one Variable Demand Polarized Vectogram [VDPV], and one based on the Wheatstone W [WW]. Participants were instructed to indicate the maximum value base-out (BO) where both image fusion and clarity was lost. Results between both sessions were compared with an analysis of differences. Results: There was found higher BO vergences results with the three devices regarding the second to the first session in the Low and Normal AC/A groups (Wilcoxon test, all p ≤ 0.013), but none in the High AC/A group (Wilcoxon test, all p ≥ 0.162). Conclusion: There is an enhancement of BO vergences in Low and normal AC/A participants but not in high AC/A participants by performing visual training with Anaglyphs, Vectograms and Cheiroscopes devices.