Relationship between visual therapy vectograms and accommodative parameters in young healthy subjects

Abstract

Purpose: Tranaglyphs and Vectograms are visual therapy materials based on red/green or polarized targets respectively that use similar but slightly different images for each eye to train fusion and vergence skills. This study aimed to analyze the relationship of three accommodative parameters (the Negative Relative Accommodation [NRA], the Positive Relative Accommodation [PRA] and the Accommodative Amplitude [AA]) with the results of four different visual therapy vectograms/tranaglyphs. Material and methods: 45 subjects free of any accommodative or binocular problem were recruited among students attending the Optometry Clinic of the Optometry Faculty (USC). In the first session, the accommodative tests were performed according to their standard protocols. In a second session, following the manufacturer’s instructions, the subjects performed in random order four different calibrated vectograms/tranaglyphs: two red/green Variable Demand Anaglyphs (one based on circles [VDA-C] and one on draws [VDA-D]), one red/green Fixed Demand Anaglyph [FDA], and one polarized with Variable Demand [VDP]. Subjects were asked to indicate the maximum value of both base-out (BO) and base-in (BI), where the image fusion was lost. Results: NRA showed a negative correlation with the BO results of the VDP (p = 0.040, r = -0.270). PRA showed a negative correlation with the BO results of the VDA-C, the VDA-D and the VDP (all p ≤0.017, r ≥ -0.323). AA showed a positive correlation with the BI results of the VDA-D, the FDA, and the VDP (all p ≤0.013, r ≥0.341). Conclusion: Accommodation seems to have some influence on the visual therapy training with vectograms and tranaglyphs.