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

Abstract

Purpose: Tranaglyphs and Vectograms are visual therapy material based on red/green or polarized targets respectively that used similar but slightly different images for each eye to train fusion and vergence skills. This study aimed to analyse 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 a first session, the accommodative tests were performed according to their standard protocols. In a second session, following manufacturer's instructions, the subjects performed in a 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 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.

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

“…In two sessions two weeks apart, following the manufacturer's instructions, the participants performed in a random order three times each, the three studied visual training tools: one red/green Fixed Demand Anaglyph [FDA], one Variable Demand Polarized Vectogram [VDPV], and one based on the Wheatstone W [WW] [2,6,15]. Participants have not performed any kind of visual therapy program or exercises between the two sessions.…”

“…FDA (Promocion Optométrica S.L., Spain) used were a single translucent card where red/green images with different prismatic demands were printed. During the procedure, the patient picks up the card at 40 cm while wearing red/green glasses [6,7]. The patient should be able to describe the picture (for example, an elephant).…”

“…Vectogram. VDVP (Promocion Optométrica S.L., Spain) used were formed by a pair of translucent slides or cards with similar images but different polarizations, which were picked by patients one over the other at 40 cm while the patients wear a pair of polarized glasses [6,7]. The patient should be able to describe the picture (for example, two circular chains).…”

“…The relationship between accommodative/vergence anomalies and an absence of a proper diagnosis or treatment could also generate other visual problems such as amblyopia, a reduction in the binocular function or stereopsis, that may end in learning disabilities or even behavioural disorders [3][4][5]. 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 [6,7]. All those tools have been usually used to practice image fusion and improvement of vergence skills [7].…”