The relationship between binocular vision symptoms and near point of convergence

Momeni‐Moghaddam, Hamed; David, A Goss; Ehsani, M.

doi:10.4103/0301-4738.97553

Cited by 27 publications

(34 citation statements)

References 14 publications

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“…The control group showed no changes in NPC distance over the same time points. This is the first report, to our knowledge, indicating that repetitive head impact with mild head acceleration negatively affected ocular NPC up to 24 h. Average NPC scores for healthy college aged population ranges from 6 to 8 cm [2,16,35,40]. The present study demonstrated similar pre-test values in the heading (8.18 ± 2.45 cm) and control (7.85 ± 1.96 cm) groups.…”

supporting

confidence: 74%

Effect of Repetitive Sub-concussive Head Impacts on Ocular Near Point of Convergence

et al. 2016

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This study intended to examine effects of repetitive sub-concussive head impacts on ocular near point of convergence (NPC). 20 healthy young adult soccer players were assigned to either a heading or control group. Heading subjects completed 10 headers of soccer balls projected at a speed of 11.2?m/s. Control subjects did not perform heading. Linear head acceleration was measured with a triaxial accelerometer. The NPC assessment was performed at pre-, 0?h post-, and 24?h post-heading. During the NPC assessment participants were seated and a visual target was moved towards the eyes at 1cm/sec. The participant signaled when he/she experienced diplopia or deviation of the eye was observed, and the distance was recorded. The assessment was repeated twice and average NPC scores were used for further analysis. Soccer heading induced mean group head accelerations of 14.49?5.4?g. Mild head impacts led to an increased NPC distance, which was supported by a significant Group x Time interaction. In the heading group, 0?h post- and 24?h post-heading NPC scores were significantly receded compared to baseline. Conversely, NPC scores for the control group showed no difference over time. Our findings indicate that mild frontal head impacts affekt NPC for a minimum of 24?h-post heading, suggesting that oculomotor processes are disrupted, at least transiently, by repetitive mild head impact.

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confidence: 74%

Effect of Repetitive Sub-concussive Head Impacts on Ocular Near Point of Convergence

et al. 2016

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“…The near point of convergence (NPC) is a basic parameter of the visual system and represents the convergence amplitude or in other words, the nearest point in space where an individual can maintain binocular fusion . Measurement of NPC is commonly done by clinicians as a routine clinical test to evaluate binocular status . The assessment of NPC is of special value in the diagnosis of convergence insufficiency (CI), which is one of the most common disorders of binocular vision.…”

mentioning

confidence: 99%

The distribution of near point of convergence and its association with age, gender and refractive error: a population‐based study

Ostadimoghaddam

Hashemi

Nabovati

et al. 2017

Clinical and Experimental Optometry

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“…However, Yeow and Taylor (1991) found that NPC decreased with an increase in age, with no significant difference between VDT and non-VDT users. Hamed, David, and Marzieh (2013) reported that the evaluation of NPC helped in the differentiation of symptomatic and asymptomatic subjects, and that the average NPC value for break point was 11.7 cm. While NPC is a measurement of how close one can bring a fixation target to the nose while maintaining fusion, NPA is used to assess the amplitude of accommodation.…”

Section: Discussionmentioning

confidence: 99%

“…Actually, most individuals addicted or immersed to computer games tend to play for prolonged hours without a break, and the effects of prolonged continuous viewing of VDTs at a near distance on physical and ocular health remain unclear. Moreover, most studies related to computer use and vision has individually evaluated physical and ocular symptoms and binocular vision (Parihar et al, 2016;Hamed et al, 2013). Unlike many studies reported in the literature related to VDT, the current study examined physical and ocular symptoms and signs (binocular functions) resulting due to prolonged computer gaming without rest for 4 h (hours) at a time, which has not been evaluated till date.…”

Section: Introductionmentioning

confidence: 99%

Peer Review #2 of "Effects of prolonged continuous computer gaming on physical and ocular symptoms and binocular vision functions in young healthy individuals (v0.2)"

2019

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Background and Objective. Addiction to computer gaming has become a social problem in Korea and elsewhere, and it has been enlisted as a mental health disorder by the World Health Organization. Most studies related to computer use and vision have individually assessed physical and ocular symptoms and binocular vision. Accordingly, the present study comprehensively assessed subjective physical and ocular symptoms and functions related to binocular vision after prolonged continuous computer gaming. This study aimed to investigate the effects of prolonged continuous computer gaming on physical and ocular health and visual functions in young healthy individuals. Methods. Fifty healthy college students (35 male/ 15 female), aged 19-35 years old, were enrolled in this study. The inclusion criteria were no binocular vision problems and no reported history of ocular disease. Participants played continuously for 4 h from 6:00 to 10:00 p.m. Physical and ocular symptoms and visual functions such as convergence, accommodation, phoria, and the blink rate were assessed before and after continuous computer gaming for 4 h. Results. Continuous computer gaming for 4 h resulted in convergence and accommodation disturbances and increased physical and ocular discomfort. Near phoria showed an exophoric shift, whereas distance phoria showed no change. Moreover, the accommodative and vergence facilities and blink rate were significantly decreased. All visual functions recovered to the baseline levels by the following morning. Discussion. Our findings suggest that excessive and continuous computer gaming impairs visual functions and causes ocular and physical fatigue. Our findings further the understanding of the adverse effects of excessive computer use on physical and ocular health, and adequate breaks are necessary to reduce physical and visual discomfort during computer gaming.

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The relationship between binocular vision symptoms and near point of convergence

Cited by 27 publications

References 14 publications

Effect of Repetitive Sub-concussive Head Impacts on Ocular Near Point of Convergence

Effect of Repetitive Sub-concussive Head Impacts on Ocular Near Point of Convergence

The distribution of near point of convergence and its association with age, gender and refractive error: a population‐based study

Peer Review #2 of "Effects of prolonged continuous computer gaming on physical and ocular symptoms and binocular vision functions in young healthy individuals (v0.2)"

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