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Early detection and prevention of vision defects
Published in Micha de Winter, Mariëlle Balledux, José de Mare, Ruud Burgmeijer, Screening in Child Health Care, 2018
Micha de Winter, Mariëlle Balledux, José de Mare, Ruud Burgmeijer
Next to the tests discussed above, Ehrlich et al. (1983) mention tests for stereoscopic vision (notably the Random Dot Stereogram (RDS)) as one of the best tests for the detection of amblyopia. When this test is used as an amblyopia screening test the basic assumption is that stereoscopic vision is one of the first visual functions lost through amblyopia. In the Netherlands too, research has been conducted into the use of such tests (for instance the TNO stereo test) for the early detection of amblyopia (Walraven & Janzen 1983, Tan-Tan 1988, Lie 1986); so far this has mainly been targeted at older pre-school children (from about 4 years). The study by Walraven and Janzen among 730 children aged 4—18 years (1983) showed the TNO test to have a sensitivity of 100% and specificity of 93% in regard to the detection of amblyopia. According to Ehrlich et al. (1983) such a test can also be used with younger children. They mention two surveys (Reinecke & Simons 1974, Simons & Reinecke 1978) in which the RDS was used with pre-school children. From these studies, it appears that the test is easy to carry out, is effective and that there is no problem in getting the children’s cooperation. Considering the positive results with similar tests in other countries, it is recommended to investigate the applicability of this method within preschool Child Health Surveillance.
The Effects of Binocular Visual Function Training after Concomitant Exotropia Surgery
Published in Current Eye Research, 2023
Jing Chen, Jin Xu, Huili Jia, Jing He, Zhengyang Tao, Ping Huang, Huahong Zhong, Hongwei Deng
The advanced 4D digital strabismus correction system that the authors employed for in-hospital training was developed according to high-tech three-dimensional (3D) multi-dimensional digital new media technology, based on the cognitive theory of visual attention in modern neuropsychology, and the principle of the synaptic plasticity-change mechanism in neurobiology. It is an approach that includes deinhibition training, abnormal retina-corresponding training, a fusion perceptual function training system, and a 3D spatial perceptual function training system, enabling it to provide targeted, individualized, and quantitative training to maximize visual stimulation according to individual patient visual function status. Moreover, it can also quantitatively provide simultaneous perceptual training for perception fusion, particularly fusion function training using random-dot stereograms. Because it can accurately capture the breakpoint of binocular single vision, it has better operability and practicality for detecting and training the fusion function using random-dot stereograms. Finally, the use of polarized light and liquid-crystal switching stereo imaging technology can be maximized for the inspection and training of stereoscopic vision. Patients were trained according to the film content and the range of the Arcsecond. Interesting training games can be developed according to different levels of stereoscopic acuity, thereby providing a diversified range of training modes and short treatment times, which can greatly improve the treatment compliance of children.
The effect of induced monocular blur by bangerter filters on measures of visual acuity and stereoacuity
Published in Strabismus, 2021
Isabel Williamson, Patrick Keating, Anne Bjerre
BF are thought to cause less disruption to binocularity than total occlusion techniques.2 The current findings mirror results found by Levi et al7 and Menon et al26 that stereoacuity was significantly reduced at each filter level. This is particularly noticeable at the point where BF reduced the right monocular VA to below 2 logMAR lines from baseline, as advised by PEDIG11 for the treatment of amblyopia. These results suggest filters do not cause less disruption to binocularity. Disparity-sensitive cells in the visual cortex responsible for stereo perception require concordant visual input from either eye.27 The random arrangement of the micro elements of BF causes imbalanced visual stimulation to either eye, inhibiting this.9,28 This study focused on fine, real depth stereoacuity, in contrast to previous studies using random dot stereograms. The effects of Trusetal filters on coarse stereoscopic depth, to which low spatial frequency tuned neurons are receptive to, requires further exploration, before final conclusions can be made regarding BF and development of gross binocular vision in amblyopic patients.29
Random Dot E Stereotest underestimates stereopsis at high test distances
Published in Clinical and Experimental Optometry, 2020
The Random Dot E Stereotest can be carried out with a long range of distances from 20-cm to 6-m.2012 However, most of the studies have been conducted within 1.5-m.2006 Underestimation of the stereopsis threshold of a subject using the Random Dot E Stereotest at a relatively long distance may be caused by the relative size of the random dots in the background. Dot sizes of random dot stereogram (RDS) were involved in previous literature. In Tortter's work, dynamic RDS with the dot size of 3.5 arcminutes, were used to study the gaze direction controls response gain in visual‐cortex neurons of monkeys;1999 the RDS with 7 arcminute dots were adopted to explore the modulation of neural stereoscopic processing by different viewing distances.1992 Stevenson et al. studied the effect of target size and eccentricity on reflex disparity vergence with 5 arcminute square dots consisting of random dot patterns.1999 In Ito's study, the dot to make up RDS was rectangular, and the horizontal pixel length (2.7 arcminutes) was larger than the vertical (1.8 arcminutes).2003 Gray et al. adopted different dot sizes and intervals to explore the motion in depth, and the smallest dot size was 2.2 arcminutes.1999 From the literature we retrieved, most of the studies related to the random dot to make up RDS, the sizes of the dots were all larger than 1 arcminute.