Agreement between clinical and laboratory methods assessing tonic and cross‐link components of accommodation and vergence

Neveu, Pascaline; Priot, Anne-Emmanuelle; Philippe, Matthieu; Fuchs, Philippe; Roumes, Corinne

doi:10.1111/cxo.12311

Cited by 5 publications

(7 citation statements)

References 75 publications

(161 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This significant accommodation should be taken into account during routine assessment (no cyclopedia) of refractive status among young people. The accommodative response in the Non-Cyc-0D was about 0.50 D greater than in the Cyc-0D with a reduced anterior chamber depth and an increased lens thickness, indicating that there was a minimal tonic accommodation in the Non-Cyc-0D eye 31 . Interestingly, the sub-foveal ChT in Non-Cyc-6D was reduced compared to Non-Cyc-0D or Cyc-6D while the ChT in Non-Cyc-0D was not different from the Cyc-0D, indicating that a greater accommodative response was associated with a thinner ChT while tonic accommodation had no effect on ChT.…”

Section: Discussionmentioning

confidence: 80%

The effect of topical administration of cyclopentolate on ocular biometry: An analysis for mouse and human models

Huang

Xie

et al. 2017

Sci Rep

View full text Add to dashboard Cite

Mydriasis with muscarinic antagonists have been used routinely prior to retinal examination and sometimes prior to refractive measurements of the mouse eye. However, biometric changes during topical administration of muscarinic antagonists have not been fully investigated in mice and humans. We found that the mouse eyes treated with cyclopentolate developed a hyperopia with a reduction in both the vitreous chamber depth and axial length. In humans, prior to the cyclopentolate treatment, a 6D accommodative stimulus produced a myopic shift with a reduced anterior chamber depth, choroidal thickness and anterior lens radius of curvature and an increase in lens thickness. After the cyclopentolate treatment, human eyes developed a hyperopic shift with an increased anterior chamber depth and anterior lens radius of curvature and a reduced lens thickness. Therefore, the biometric changes associated with this hyperopic shift were mainly located in the posterior segment of the eye in mice. However, it is the anterior segment of the eye that plays a main role in the hyperopic shift in human subjects. These results further indicate that mouse eyes do not have accommodation which needs to be taken into account when they are used for the study of human refractive errors.

show abstract

Section: Discussionmentioning

confidence: 80%

The effect of topical administration of cyclopentolate on ocular biometry: An analysis for mouse and human models

Huang

Xie

et al. 2017

Sci Rep

View full text Add to dashboard Cite

show abstract

“…However, several other studies [15][16][17] have found no significant change in the AC/A ratio. Based on a previous study, 26 the coefficient of repeatability is 0.277 MA/D for the AC/A ratio. This variability may have masked any effect for the AC/A ratio.…”

Section: Discussionmentioning

confidence: 96%

“…It was calibrated for each participant at the beginning of the experiment. [21][22][23][24][25][26] To perform the calibration, the right eye was occluded with a Wratten filter while the left eye fixated a Maltese cross at infinity (viewed through the haploscope device); during fixation with the left eye, trial lenses (þ4 D to À4 D in 1-D step) were placed in front of the right occluded eye; measured refraction was compared to the refraction expected from the trial lenses considering a distance of 12 mm between the lens and the eye. A correction factor was obtained from the linear regression between PR II refraction and expected refraction.…”

Section: Assessment Apparatusmentioning

confidence: 99%

See 1 more Smart Citation

Stereoscopic Viewing Can Induce Changes in the CA/C Ratio

Neveu¹,

Roumes²,

Philippe³

et al. 2016

Invest. Ophthalmol. Vis. Sci.

Self Cite

View full text Add to dashboard Cite

Citation: Neveu P, Roumes C, Philippe M, Fuchs P, Priot A-E. Stereoscopic viewing can induce changes in the CA/C ratio. Invest Ophthalmol Vis Sci. 2016;57:4321-4326. DOI:10.1167/ iovs.15-18854 PURPOSE. Stereoscopic displays challenge the neural cross-coupling between accommodation and vergence by inducing a constant accommodative demand and a varying vergence demand. Stereoscopic viewing calls for a decrease in the gain of vergence accommodation, which is the accommodation caused by vergence, quantified by using the convergenceaccommodation to convergence (CA/C) ratio. However, its adaptability is still a subject of debate.METHODS. Cross-coupling (CA/C and AC/A ratios) and tonic components of vergence and accommodation were assessed in 12 participants (27.5 6 5 years, stereoacuity better than 60 arc seconds, 6/6 acuity with corrected refractive error) before and after a 20-minute exposure to stereoscopic viewing. During stimulation, vergence demand oscillated from 1 to 3 meter angles along a virtual sagittal line in sinusoidal movements, while accommodative demand was fixed at 1.5 diopters. RESULTS.Results showed a decreased CA/C ratio (À10.36%, df ¼ 10, t ¼ 2.835, P ¼ 0.018), with no change in the AC/A ratio (P ¼ 0.090), tonic vergence (P ¼ 0.708), and tonic accommodation (P ¼ 0.493).CONCLUSIONS. These findings demonstrated that the CA/C ratio can exhibit adaptive adjustments. The observed nature and amount of the oculomotor modification failed to compensate for the stereoscopic constraint.Keywords: accommodation, vergence, CA/C, stereoscopic viewing A ccommodation and vergence are neurologically crosscoupled and interact dynamically, so that an accommodative stimulus induces both accommodative and vergence responses-and vice versa for a vergence stimulus. The vergence evoked by accommodation, known as accommodative vergence, can be quantified by using the AC/A ratio, which assesses the amount of vergence per unit change in accommodation. The accommodation induced by vergence, known as vergence accommodation, can be quantified by using the CA/C ratio, which measures the amount of accommodation per unit change in vergence. Different static and dynamic models of the accommodative and vergence systems have been proposed to provide an understanding of the organization and the interaction between the two systems.

show abstract

“…Further, vergence movements can be divided into a transient and a sustained part [92]. The transient part is fast and preprogrammed and initiates the response, while the sustained part is slow and under feedback control and brings the eyes to the final, accurate position [92, 93]. It could be possible that there is an effect of familiar size on vergence distance when the vergence movement is first programmed (in the transient part), but is corrected during the movement by the sustained part through the disparity feedback loop.…”

Section: Discussionmentioning

confidence: 99%

Size matters: How reaching and vergence movements are influenced by the familiar size of stereoscopically presented objects

Schubert¹,

Jung²,

Helmert³

et al. 2019

PLoS ONE

View full text Add to dashboard Cite

The knowledge about the usual size of objects—familiar size—is known to be a taken into account for distance perception. The influence of familiar size on action programming is less clear and has not yet been tested with regard to vergence eye movements. In two experiments, we stereoscopically presented everyday objects, such as a credit card or a package of paper tissues, and varied the distance as specified by binocular disparity and the distance as specified by familiar size. Participants had to fixate the shown object and subsequently reach towards it either with open or with closed eyes. When binocular disparity and familiar size were in conflict, reaching movements revealed a combination of the two depth cues with individually different weights. The influence of familiar size was larger when no visual feedback was available during the reaching movement. Vergence movements closely followed binocular disparity and were largely unaffected by familiar size. In sum, the results suggest that in this experimental setting familiar size is taken into account for programming and executing reaching movements while vergence movements are primarily based on binocular disparity.

show abstract

Agreement between clinical and laboratory methods assessing tonic and cross‐link components of accommodation and vergence

Cited by 5 publications

References 75 publications

The effect of topical administration of cyclopentolate on ocular biometry: An analysis for mouse and human models

The effect of topical administration of cyclopentolate on ocular biometry: An analysis for mouse and human models

Stereoscopic Viewing Can Induce Changes in the CA/C Ratio

Size matters: How reaching and vergence movements are influenced by the familiar size of stereoscopically presented objects

Contact Info

Product

Resources

About