Quantification of heterophoria and phoria adaptation using an automated objective system compared to clinical methods

Han, Sang Jin; Guo, Yi; Granger-Donetti, BÃ©rangÃ ̈re; Vicci, Vincent R.; Alvarez, Tara L.

doi:10.1111/j.1475-1313.2009.00681.x

Cited by 45 publications

(45 citation statements)

References 37 publications

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“…28,29 This software was designed to independently generate visual stimuli to the left and right eye with the use of two monitors and two partially (50%) reflecting mirrors. The VisualEyes program produces a stimulus in each monitor that is transposed onto reflective mirrors.…”

Section: Methodsmentioning

confidence: 99%

Objective Assessment of Vergence after Treatment of Concussion-Related CI: A Pilot Study

Scheiman

Talasan²,

Mitchell³

et al. 2017

Optom Vis Sci

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Purpose To evaluate changes in objective measures of disparity vergence after office-based vision therapy (OBVT) for concussion-related convergence insufficiency (CI), and determine the feasibility of using this objective assessment as an outcome measure in a clinical trial. Methods This was a prospective, observational trial. All participants were treated with weekly OBVT with home reinforcement. Participants included two adolescents and three young adults with concussion-related, symptomatic CI. The primary outcome measure was average peak velocity for 4-degree symmetrical convergence steps. Other objective outcome measures of disparity vergence included time to peak velocity, latency, accuracy, settling time, and main sequence. We also evaluated saccadic eye movements using the same outcome measures. Changes in clinical measures (near point of convergence, positive fusional vergence at near, Convergence Insufficiency Symptom Survey (CISS) score) were evaluated. Results There were statistically significant and clinically meaningful changes in all clinical measures for convergence. Four of the five subjects met clinical success criteria. For the objective measures, we found a statistically significant increase in peak velocity, response accuracy to 4° symmetrical convergence and divergence step stimuli and the main sequence ratio for convergence step stimuli. Objective saccadic eye movements (5° and 10°) appeared normal pre-OBVT, and did not show any significant change after treatment. Conclusions This is the first report of the use of objective measures of disparity vergence as outcome measures for concussion-related convergence insufficiency. These measures provide additional information that is not accessible with clinical tests about underlying physiological mechanisms leading to changes in clinical findings and symptoms. The study results also demonstrate that patients with concussion can tolerate the visual demands (over 200 vergence and versional eye movements) during the 25-minute testing time and suggest that these measures could be used in a large-scale randomized clinical trial of concussion-related CI as outcome measures.

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Section: Methodsmentioning

confidence: 99%

Objective Assessment of Vergence after Treatment of Concussion-Related CI: A Pilot Study

Scheiman

Talasan²,

Mitchell³

et al. 2017

Optom Vis Sci

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“…The phoria level was calculated by averaging the last three seconds of the right eye response based upon prior published data from where a steady state is reached within 12 seconds. Examples of phoria responses have been demonstrated in this laboratory’s previous studies 35, 47, 62–64 .…”

Section: Methodsmentioning

confidence: 63%

“…One fusional cycle was defined as fusion of a near target for both the 3 BI and 12 BO prisms 60, 61 . Symptoms were assessed using the convergence insufficiency symptom survey (CISS) 47 . A haploscope set-up was used to control the visual stimuli to both eyes independently.…”

Section: Methodsmentioning

confidence: 99%

Adaptation to Progressive Additive Lenses: Potential Factors to Consider

Alvarez

Kim

Granger-Donetti

2017

Sci Rep

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People develop presbyopia as part of the normal aging process. Most presbyopes adapt to progressive additive lens (PALs), while others do not. This investigation sought to determine whether the ability to modify disparity vergence or phoria was correlated to PALs adaptation. In experiment 1, a double-step paradigm quantified the ability to modify convergence responses in sixteen presbyopes. In experiment 2, thirty-one incipient presbyopes participated in a 5-minute sustained fixation task to evoke phoria adaptation where the magnitude and rate of phoria adaptation were measured. Then, the experiment was repeated after wearing PALs for one month. Linear regression analyses were conducted between the following parameters: near point of convergence, positive fusional vergence at near, vergence facility, net change in the magnitude of phoria adaptation, and the rate of phoria adaptation. The ability to change convergence average peak velocity was significantly greater (p < 0.03) in presbyopic PALs adapters compared to presbyopic PALs non-adapters. The rate of phoria adaptation and vergence facility were significantly greater (p < 0.03) in incipient presbyopic PALs adapters compared to incipient presbyopic PALs non-adapters. Vergence facility and the rate of phoria adaptation may have potential clinical utility in differentiating which patients may adapt to PALs and which ones will have more difficulty.

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“…We have validated this method of measuring phoria using the VisualEyes System. 6,7,8 Applications and Significance:…”

Section: Possible Modificationsmentioning

confidence: 99%

VisualEyes: A Modular Software System for Oculomotor Experimentation

Guo

Kim

Alvarez

2011

JoVE

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Eye movement studies have provided a strong foundation forming an understanding of how the brain acquires visual information in both the normal and dysfunctional brain. 1 However, development of a platform to stimulate and store eye movements can require substantial programming, time and costs. Many systems do not offer the flexibility to program numerous stimuli for a variety of experimental needs. However, the VisualEyes System has a flexible architecture, allowing the operator to choose any background and foreground stimulus, program one or two screens for tandem or opposing eye movements and stimulate the left and right eye independently. This system can significantly reduce the programming development time needed to conduct an oculomotor study. The VisualEyes System will be discussed in three parts: 1) the oculomotor recording device to acquire eye movement responses, 2) the VisualEyes software written in LabView, to generate an array of stimuli and store responses as text files and 3) offline data analysis. Eye movements can be recorded by several types of instrumentation such as: a limbus tracking system, a sclera search coil, or a video image system. Typical eye movement stimuli such as saccadic steps, vergent ramps and vergent steps with the corresponding responses will be shown. In this video report, we demonstrate the flexibility of a system to create numerous visual stimuli and record eye movements that can be utilized by basic scientists and clinicians to study healthy as well as clinical populations. ProtocolAn overview of the key elements needed to conduct an oculomotor experiment is shown in figure 1. Each block in the flow chart will be discussed in detail below. INSTRUMENTATION SET-UP:2. CALIBRATION: VISUALEYES SOFTWARE:Page 1 of 6 Journal of Visualized Experiments www.jove.comCopyright © 2011 Journal of Visualized Experiments 1. Any type of eye movement monitor can be used for this system. We will demonstrate an infrared limbus tracking and a video monitoring system. 2. For tandem tracking movements such as saccadic or smooth pursuit, a single computer can be used for the visual display. To study opposing eye movements such as vergence or the interaction of vergence with tandem version movements (ie, vergent with saccadic stimuli) a haploscope is needed with two computer monitors for visual display, see figure 2.1. Calibration is needed to convert one set of metrics into another. Eye movements are typically indicated in degrees (°) of rotation shown in figure 3. However, computer monitors use pixel values compared to vision researchers who often denote the visual stimuli in degrees. Hence, a conversion is needed to convert the pixel values to degrees. One can use trigonometry to calculate where to place the physical targets to calibrate the visual displays. For example, if the stimulus on the computer screen aligns with a 2°physical target (see figure 2) then that pixel value corresponds to a 2°stimulus. 2. To calibrate the system, the operator needs to open Pixel2Deg.vei within the Vi...

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Quantification of heterophoria and phoria adaptation using an automated objective system compared to clinical methods

Abstract: This objective limbus tracking system offers a better means by which to study the phoria and its adaptation throughout an eye movement experiment. The broader aim of this research is to establish a tool that will further the basic science of oculomotor control and binocular dysfunctions.

Cited by 45 publications

References 37 publications

Objective Assessment of Vergence after Treatment of Concussion-Related CI: A Pilot Study

Objective Assessment of Vergence after Treatment of Concussion-Related CI: A Pilot Study

Adaptation to Progressive Additive Lenses: Potential Factors to Consider

VisualEyes: A Modular Software System for Oculomotor Experimentation

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