Near Heterophoria in Early Childhood

Babinsky, Erin; Sreenivasan, Vidhyapriya; Candy, T. Rowan

doi:10.1167/iovs.14-14649

Cited by 24 publications

(44 citation statements)

References 59 publications

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“…On average, there was less than 1 pd difference in the phoria magnitude between the alternating and the unilateral short cover protocol, while the unilateral long cover revealed larger phorias especially at the closest viewing distance in both adults and young children. These results agree with previous studies showing larger phorias after prolonged dissociation . This change in heterophoria with duration has been attributed to the decay of slow fusional vergence and so these results suggest that young children are capable of undergoing adaptation, supporting the results of other recent studies …”

Section: Discussionsupporting

confidence: 93%

“…The instrument uses default average calibration functions based on data collected from adults, but these calibration factors have been found to be variable across subjects . For this reason, individual calibrations of refractive state (lens calibration) and gaze (prism calibration) were performed for all subjects using a technique described elsewhere . The mean relative calibration slopes were similar for adults and children ( Prism calibration : Adults: −0.80 ± 0.20; Children: −0.92 ± 0.28; Lens calibration : Adults: 1.11 ± 0.22; Children: 1.04 ± 0.24).…”

Section: Methodsmentioning

confidence: 99%

“…Maddox originally suggested that the phoria position represents the combined contributions of tonic, proximal and accommodative vergence activity. Thus, the phoria could be influenced by factors such as the content of the visual stimulus and its viewing distance, which both influence accommodation and proximal responses, or the method and time of dissociation when tonic adaptation can impact the phoria estimate . Other factors such as age and refractive error also play a role in determining its magnitude .…”

Section: Introductionmentioning

confidence: 99%

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The heterophoria of 3–5 year old children as a function of viewing distance and target type

Troyer

Sreenivasan

Peper

et al. 2016

Ophthalmic Physiologic Optic

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Purpose Heterophoria is the misalignment of the eyes in monocular viewing and represents the accuracy of vergence driven by all classical cues except disparity. It is challenging to assess restless children using clinical cover tests, and phoria in early childhood is poorly understood. Here we used eye tracking to assess phoria as a function of viewing distance and target in adults and young children, with comparison to clinical cover tests. Methods Purkinje image tracking (MCS PowerRefractor) was used to record eye alignment in adults (19–28 years, N = 24) and typically developing children (three to five years, N = 24). Objective unilateral and alternating cover tests were performed using an infrared filter while participants viewed a pseudo-randomised sequence of Lea symbols (0.18 logMAR; Snellen: 20/30 or 6/9) and animated cartoon movies at distances of 40 cm, 1 m, and 6 m. For the unilateral cover test, a 10 second binocular period preceded and followed 30 seconds of occlusion of the right eye. For the alternating cover test, a 10 second binocular period preceded and followed alternate covering of right and left eyes for three seconds each. Phoria was derived from the difference in weighted average binocular and monocular alignment. A masked prism-neutralised clinical cover test was performed for each of the conditions for comparison. Results Closer viewing distance resulted in greater exophoria for both children and adults (p < 0.001). Phorias were similar for adults and children for each viewing distance and target, with mean differences of less than 2 prism dioptres or pd. Overall, the average PowerRefractor phorias in pd (pooled across protocols) for adults were 1.3, 2.3 and 3.8 pd exophoria and for children were 0.1 pd esophoria, 0.94 and 3.8 pd exophoria for the 6 m, 1 m and 40 cm distances respectively. The corresponding clinical cover test values were 0.7, 1.9, and 4.1 pd exophoria for adults and 0, 1.5 and 3.3 pd exophoria for the children. Refractive states were also similar (≤ 0.5 D) for viewing the Lea symbols or movie for any protocol tested. Conclusions Phoria estimation can be challenging for a pre-school child. These data suggest that by three to five years of age objective eye-tracking measures in a typically developing group are adult-like at the range of distances tested, and that use of an animated movie produces similar average results to a small optotype (0.18 logMAR; Snellen 20/30 or 6/9).

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Section: Discussionsupporting

confidence: 93%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The heterophoria of 3–5 year old children as a function of viewing distance and target type

Troyer

Sreenivasan

Peper

et al. 2016

Ophthalmic Physiologic Optic

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show abstract

“…In this study, we excluded the results of the under‐10‐years age group due to the possibility of data inaccuracy, so that prevalence estimates would be as close to true values as possible. Another explanation for the higher prevalence of convergence insufficiency in children is that children may have lower accommodative convergence/accommodation (AC/A) ratios compared to adults and this may result in under‐convergence (exophoria), even in the presence of accurate accommodation at near . Furthermore, higher demand for near work (due to school work and home work) can also explain the higher prevalence of convergence insufficiency in children.…”

Section: Discussionmentioning

confidence: 99%

The prevalence of convergence insufficiency in Iran: a population‐based study

Hashemi

Nabovati

Khabazkhoob

et al. 2017

Clinical and Experimental Optometry

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“…and its examination,both diatance and near, is essential to diagnose binocular disorders [1]. In 2015, Babinsky et al [2] conducted heterophroia exams on 50 children (refractive diopter: -1.25D to +3.75D) and 12 orthophoria adults, their results showed that 78% children and 69% adults manifested exophoria defined by over two prism degree, and only 20% children and 23% adults had orthophoria(the degree of deviation was within two prism degree, including each two-prism-degree exophoria and esophoria), and only one kid and one adult had esphoria over two prism degrees.…”

Section: Introductionmentioning

confidence: 99%

A Clinical Investigation about Horizontal Heterophoria Among Newly Diagnosed Myopia Juveniles in Nanchong District of China

Yan

Wang

et al. 2019

Preprint

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Background: To establish the prevalence and distribution of heterophoria in low myopia juveniles and and provide evidence of myopia prevention and treatment. Methods: Near and distant heterophoria were administered to the patients who were diagnosed of low myopia at their first visit in clinic. Tthe Von Graefe method was performed to test near, distant horizontal heterophoria types and degrees. Statistical analysis was performed with SPSS17.0 software. Results: A total of 150 students were participated in this study. Distant and near phoria was detected in 92.67% and 96.00% of the students respectively. exophoria was more common than esophoria(diantant:79.33% vs 13.33%; near:86.67% vs 9.33%, P<0.05), and the mean deviation of diantant and near heterophoria was -1.97△ and -3.91△. There was a statistical difference between the near and distant heterophoria (P<0.05). Conclusions: Most myopia juveniles have different extents of exophoria. Due to the high prevalence of heterophoria in myopia, in the process of refraction, attention should be paid to the examination of binocular visual function parameters such as heterophoria, which is conducive to the issuance of suitable optical correction prescriptions and the reasonable measures for myopia prevention and control. Keywords: Heterophoria, myopia, juvenile school students

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Near Heterophoria in Early Childhood

Abstract: Despite developmental maturation of interpupillary distance, refractive error, and AC/A, in a typical sample of young children the predominant dissociated position is one of exophoria.

Cited by 24 publications

References 59 publications

The heterophoria of 3–5 year old children as a function of viewing distance and target type

The heterophoria of 3–5 year old children as a function of viewing distance and target type

The prevalence of convergence insufficiency in Iran: a population‐based study

A Clinical Investigation about Horizontal Heterophoria Among Newly Diagnosed Myopia Juveniles in Nanchong District of China

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