Aug 2026· Strabismus· Vol 34, pp. 59 - 70· 0 citations· 42 references
Medicine
TL;DR
There was a significant relationship between convergence fusion range and stereoacuity measured using the Frisby and Real Depth stereo tests in this population of adults with normal binocular single vision.
Abstract
ABSTRACT Purpose: To explore the relationship between motor fusion and stereoacuity in adults with normal binocular single vision. Method: A sample of 31 adult participants was recruited by convenience sampling. The inclusion criteria included age 18–40 and no history of uncorrectable vision loss or strabismus. Examinations included visual acuity, orthoptic assessment and non-cycloplegic autorefraction (Canon RK-F2). Stereoacuity was performed using Precision Vision’s Real Depth Stereo Test, Frisby Stereo Test, Titmus Stereo Fly Test and TNO. Prism fusion ranges were performed at 33 cm and 6 m, using an accommodative target. Written informed consent was obtained from all participants prior to the examination. Results: Participants had a mean age of 23.16 ± 2.48 years, were 80.6% female and 71% had myopia. Most were orthophoric (58.1%) at distance fixation and exophoric (67.7%) at near fixation. There was a moderate and significant correlation between distance and near convergence by prism fusion ranges (r = 0.64, p < .001). There was a moderate negative correlation between near convergence by prism fusion and stereoacuity using the Real Depth Stereo Test (r = −0.42, p = .018) and Frisby Stereo Test (r = −0.52, p = .003). However, there was no correlation between near convergence by prism fusion with Titmus (r = 0.19, p = .36) or TNO (r = −0.31, p = .1). Near divergence fusion range was not significantly correlated to any stereoacuity test (all p > .05). Conclusion: There was a significant relationship between convergence fusion range and stereoacuity measured using the Frisby and Real Depth stereo tests in this population of adults with normal binocular single vision.
This prototype MRG image translocation software was helpful to 69% of patients with binocular diplopia, but limited by large angle strabismus because of the limited instrument field of view.
Edsel B Ing, Kevin Sha, Sarosh Dandoti et al.· Journal of neuro-ophthalmolo...· 0 citations
Purpose Accurate stereoacuity assessment is essential for evaluating binocular vision, yet non-visual factors such as instruction quality and task execution time might influence performance on random-dot stereotest in adults with normal binocular vision. Methods In this randomized controlled study, 100 adults (mean age 26.4 ± 5.17 years) with normal binocular vision were assigned to a control group (n = 40) or an experimental group (n = 60). All participants completed two consecutive administrations of the Random Dot 2 Stereo Acuity Test with LEA Symbols in an immediate test–retest paradigm. In the control group, both administrations followed standard manufacturer instructions. In the experimental group, the second (retest) administration was preceded by a detailed explanation supported by visual examples of possible target shapes. Stereoacuity (in arcseconds) and test completion time (in seconds) were recorded to evaluate the effect of enhanced instruction on retest performance. Results The control group showed no significant change in stereoacuity between measurements (mean change: 0.03 log10 arcsec, p = 0.125). In contrast, the experimental group demonstrated a significant improvement (mean change: 0.45 log10 arcsec, p < 0.0001), with most participants reaching the test’s finest disparity level (63 arcsec). Changes in response time did not differ between groups (p = 0.063). However, in the experimental group, greater improvements in stereoacuity were strongly associated with longer post-test response times (p < 0.0001). Conclusion Enhanced instructions with visual cues significantly improved stereoacuity outcomes beyond expected test–retest variability, highlighting the importance of instruction quality and task engagement in stereopsis assessment, which should be carefully considered in both clinical practice and research settings.
M. Argilés, Valldeflors Vinuela-Navarro, Luis Pérez-Maña et al.· Journal of Optometry· 0 citations
Purpose To evaluate multi-distance binocular visual function in children using a tablet-based dichoptic platform and compare performance between single-vision and highly aspherical lenslet (HAL) spectacle lenses. Methods This cross-sectional study included 300 children aged 4 to 17 years wearing single-vision spectacle lenses (n = 154) or HAL spectacle lenses (n = 146). Outcomes included foveal simultaneous-perception non-composite responses, peripheral simultaneous-perception non-normal responses, and fine, dynamic, and gross stereopsis from 0.4 to 3.0 m. Generalized estimating equations clustered by participant evaluated lens type and testing distance, with adjustment for age, sex, myopia magnitude, interocular spherical-equivalent difference, and mean absolute cylinder. Results Fine stereopsis declined significantly as testing distance increased and was rarely measurable at 2.0 m. Compared with 0.4 m, the adjusted odds of measurable fine stereopsis were lower at 1.5 m (adjusted odds ratio [aOR] = 0.81; P = 0.003) and 2.0 m (aOR = 0.08; P < 0.001). In adjusted observational analyses, HAL lens wear was associated with higher odds of measurable dynamic (aOR = 1.68; P = 0.024) and gross stereopsis (aOR = 2.51; P = 0.006) than single-vision lens wear. Fine stereopsis remained comparable between the two groups (aOR = 0.99; P = 0.960). Foveal non-composite responses were uncommon at 0.4 m but highly prevalent at 3.0 m (>87%) regardless of lens type, while peripheral simultaneous perception remained mostly normal. Conclusions Tablet-based binocular visual performance declined as the testing distance increased. In this cross-sectional observational analysis, children wearing HAL spectacle lenses showed higher adjusted odds of measurable dynamic and gross stereopsis than those wearing single-vision lenses, while fine stereopsis remained comparable. These findings provide preliminary clinical evidence regarding binocular visual performance with HAL lens wear and warrant confirmation in longitudinal studies across different myopia levels.
Zhuotong Wu, Yuhao Ye, Yong Ma et al.· Clinical Ophthalmology· 0 citations
Purpose To evaluate the association between Active Vision Therapy (AVT) combined with occlusion and occlusion-only therapy in task-based saccadic and pursuit visuomotor performance and visual outcomes in children with anisometropic amblyopia. Methods Forty children (median age=9years, IQR=7–11) with persistent anisometropic amblyopia after six weeks of spectacle adaptation were alternately assigned to AVT–occlusion (n = 23) or occlusion-only (n = 17). BCVA, stereopsis, contrast sensitivity, and task-based saccadic and smooth pursuit performance were measured at baseline, three weeks, six weeks, and three months. AVT included structured monocular and binocular exercises using Vision Training System 4 and Cheiroscope, while occlusion involved daily patching of the fellow eye. Repeated-measures ANOVA and Friedman tests evaluated changes over time, partial Spearman correlations adjusted for group examined associations between oculomotor and visual improvements. Results Both groups improved in BCVA, and task-based saccadic and smooth pursuit performance (p < 0.05) in the AVT–occlusion group. Significant time × therapy interactions were found for BCVA, task-based saccadic and smooth pursuit performance, and contrast sensitivity (p ≤ 0.03). At three months, AVT–occlusion outperformed occlusion-only in BCVA (−0.13 logMAR, p = 0.01), task-based saccadic response time (−0.78 ms equivalent, P < 0.001) and task-based smooth pursuit performance (4.68%, p = 0.03), and contrast sensitivity (0.06 log-units, p = 0.005). Greater gain in task-based saccadic (ρ=-0.43, p = 0.006) and smooth pursuit (ρ=-0.53, p = 0.001) performance correlated with BCVA improvement; faster saccadic response performance (ρ=0.35, p = 0.026) correlated with better stereopsis. Conclusions AVT with occlusion was associated with greater improvements in functional visuomotor task performance and visual outcomes in children with anisometropic amblyopia, supporting its role as a function-oriented adjunct to conventional therapy.
Manisha Koirala, Sanjeev Bhattarai, J. Shrestha et al.· Journal of Optometry· 0 citations
ABSTRACT Background: Impaired depth perception can be caused by monocular blur and is assessed with a range of stereotests, but differences in test presentation result in varying outcomes. A new testing system Optonet includes a stereo test which has not been evaluated in terms of the impact of blur; therefore, the aim of this study was to compare the effect of simulated impaired visual acuity across differing stereotests including Optonet. Method: Participants aged ≥18 years with visual acuity ≤0.3 logMAR in either eye and <0.2 logMAR interocular difference were included. Visual acuity (VA) was tested using the ETDRS test for near (40cms) and distance (4 meters). Stereoacuity was measured with Frisby, TNO, and Optonet, a random dot-based test on an iPad with red/blue glasses. Blur was induced with Bangerter foils 0.2 and 0.4 and VA and stereodata were remeasured. An arbitrary value of 5000” of arc was given if stereoacuity was not measurable. Results: Twenty-five participants (23 females and 2 males), median age 21 (IQR:2, Range 19–38), were included. Near VA (Median ± IQR) with 0.2 and 0.4 Bangerter foil (right eye) was 0.36 ± 0.18 and 0.50 ± 0.19 logMAR, respectively, with 0.00 ± 0.15 logMAR in left eye. TNO demonstrated the largest degradation compared to Frisby and Optonet (no foil: 60” (TNO) 20” (Frisby) 40” (Optonet), 0.2 foil: 240” (TNO) 40” (Frisby) 119” (Optonet), 0.4 foil: 2000” (TNO) 85” (Frisby) 158” (Optonet)). Significant differences in the amount that stereoacuity was reduced occurred between Frisby and TNO (p < .05, Friedman’s two-way analysis of variance). Conclusion: Differences in stereoacuity are evident across stereotests under simulated conditions of blur. For accurate repeatable measures of stereoacuity, a consistent stereotest should be used. Random dot tests such as TNO and Optonet are impacted more by blur than Frisby with Optonet showing the greatest sensitivity to blur.
J. Mehta, Anna O'Connor, Roisin Buckels· Strabismus· 0 citations
Purpose To quantitatively evaluate vergence-related eye movements in acquired comitant esotropia (ACE) using video-based eye tracking and to characterize abnormal movement patterns and their postoperative changes. Methods We studied 46 patients with ACE (mean age, 24.3 years) who underwent unilateral or bilateral medial rectus recession. Binocular gaze was recorded at 300 Hz (Tobii Pro Spectrum) while participants alternately fixated every 5 seconds on a near target (30 cm) and a far target (60 cm). Stable amplitude was the difference between the mean near- and far-target gaze angles in the 3- to 4-second period after each target step. Eye movements were classified as conjugate or vergence according to the direction of stable amplitude in each eye. Saccadic onset, offset, and postsaccadic stabilization metrics were extracted. Statistical analyses included logistic regression and Wilcoxon signed-rank tests. Results Despite vergence stimulation, 26 patients (56.5%) exhibited conjugate movements, whereas 20 patients (43.5%) showed vergence movements. Conjugate movements were associated with a larger absolute stable amplitude of the fixating eye, larger absolute saccadic amplitudes in both eyes, and a smaller interocular difference in saccadic amplitude (fixating – non-fixating; all P < 0.05). In addition, interocular differences were observed in stabilization time and amplitude, particularly in the vergence group. Postoperatively, conjugate movements decreased markedly, as 81.8% of patients (18/22) demonstrated vergence movements at 1 month, and 92.3% (12/13) at ≥3 months. Conclusions Video-based eye tracking revealed frequent conjugate movements during vergence stimulation in ACE. After medial rectus recession surgery, vergence responses increased substantially, suggesting restoration of coordinated binocular motor control.
Junichiro Hiratake, Yoshihito Mochizuki, Y. Okita et al.· Investigative Ophthalmology...· 0 citations