A novel paediatric game-based visual-fields assessor

Capturing attention improves accommodation: An experimental study in children with ADHD using multiple object tracking

The present study was aimed at assessing the impact of manipulating the attentional load using a multiple object tracking (MOT) task on the dynamics of the accommodative response in children with attention deficit hyperactivity disorder (ADHD). The pupil size was recorded to assess the effectiveness of the experimental manipulation, and the role of ADHD medication was also explored. The accommodative and pupil dynamics (magnitude and variability) were monitored with an open-field autorefractometer (WAM-5500) in 41 children with ADHD (24 non-medicated and 17 medicated) and 21 non-ADHD controls, while they performed the MOT task with four different levels of complexity (i.e., tracking zero, one, two, or three targets). We found that increasing the attentional load caused a heightened accommodative response, showing a negative association between MOT complexity and accommodative lag in children with ADHD and non-ADHD controls. Complementarily, the pupil size increased as a function of task complexity, confirming a successful experimental manipulation. The stability of accommodation was insensitive to the attentional manipulation, but it differed between groups. Specifically, non-medicated children with ADHD exhibited a greater variability of accommodation in comparison to controls. Increasing the attentional load is associated with a reduction in the accommodative lag in children with ADHD and controls. Our findings show that the allocation of attention plays an important role in the dynamics of the accommodative response, which may be of relevance in the diagnosis and treatment of accommodative deficits in children with and without ADHD.

Comparison of Quality and Output of Different Optimal Perimetric Testing Approaches in Children With Glaucoma

Importance

There is limited evidence to support the development of guidance for visual field testing in children with glaucoma.

Objective

To compare different static and combined static/kinetic perimetry approaches in children with glaucoma.

Design, Setting, and Participants

Cross-sectional, observational study recruiting children prospectively between May 2013 and June 2015 at 2 tertiary specialist pediatric ophthalmology centers in London, England (Moorfields Eye Hospital and Great Ormond Street Hospital). The study included 65 children aged 5 to 15 years with glaucoma (108 affected eyes).

Main Outcomes and Measures

A comparison of test quality and outcomes for static and combined static/kinetic techniques, with respect to ability to quantify glaucomatous loss. Children performed perimetric assessments using Humphrey static (Swedish Interactive Thresholding Algorithm 24-2 FAST) and Octopus combined static tendency-oriented perimetry/kinetic perimetry (isopter V4e, III4e, or I4e) in a single sitting, using standardized clinical protocols, administered by a single examiner. Information was collected about test duration, completion, and quality (using automated reliability indices and our qualitative Examiner-Based Assessment of Reliability score). Perimetry outputs were scored using the Aulhorn and Karmeyer classification. One affected eye in 19 participants was retested with Swedish Interactive Thresholding Algorithm 24-2 FAST and 24-2 standard algorithms.

Results

Sixty-five children (33 girls [50.8%]), with a median age of 12 years (interquartile range, 9-14 years), were tested. Test quality (Examiner-Based Assessment of Reliability score) improved with increasing age for both Humphrey and Octopus strategies and were equivalent in children older than 10 years (McNemar test, χ2 = 0.33; P = .56), but better-quality tests with Humphrey perimetry were achieved in younger children (McNemar test, χ2 = 4.0; P = .05). Octopus and Humphrey static MD values worse than or equal to -6 dB showed disagreement (Bland-Altman, mean difference, -0.70; limit of agreement, -7.74 to 6.35) but were comparable when greater than this threshold (mean difference, -0.03; limit of agreement, -2.33 to 2.27). Visual field classification scores for static perimetry tests showed substantial agreement (linearly weighted κ, 0.79; 95% CI, 0.65-0.93), although 25 of 80 (31%) were graded with a more severe defect for Octopus static perimetry. Of the 7 severe cases of visual field loss (grade 5), 5 had lower kinetic than static classification scores.

Conclusions and Relevance

A simple static perimetry approach potentially yields high-quality results in children younger than 10 years. For children older than 10 years, without penalizing quality, the addition of kinetic perimetry enabled measurement of far-peripheral sensitivity, which is particularly useful in children with severe visual field restriction.

Visual function in children with primary brain tumors

PURPOSE OF REVIEW

To review the recent advances in understanding how primary brain tumors affect vision in children.

RECENT FINDINGS

Children with primary brain tumors may have vision loss due to involvement of their afferent visual pathways or from papilledema. These vision deficits may go unrecognized until later in life, years after treatment of the primary lesion. Strabismus and cranial nerve palsies may occur as a result of brain tumors. Ophthalmologists can monitor and treat young children at risk for vision loss from amblyopia as a result of effects from their underlying lesion. Advances in imaging techniques have made it possible to quantify damage to the visual pathways with objective tests.

SUMMARY

Systematic referrals for evaluation by an ophthalmologist should occur early in the course of treatment of primary brain tumors as these evaluations may improve visual outcomes and quality of life.

Clinical applicability of the Saccadic Vector Optokinetic Perimeter in children with and without visual impairment

BACKGROUND

Common paediatric perimetry techniques require central fixation and subjective responses, which may be challenging for young or cognitively impaired children. The Saccadic Vector Optokinetic Perimeter (SVOP) was designed to overcome these challenges by using infra-red eye tracking to assess the visual field. This study assessed the clinical feasibility of SVOP in children without visual impairment, comparing it to current paediatric techniques, and in children with visual impairment.

METHODS

Participants were recruited into two cohorts: children without visual impairment (visual acuity ≥ 6/7.5) and children with visual impairment (visual acuity ≤ 6/18). Children without visual impairment attempted the Goldmann perimeter, confrontation method, and SVOP. Children with visual impairment attempted SVOP, when clinically indicated, as part of a full ophthalmic assessment. Visual field results and test length were recorded.

RESULTS

Twenty-three children without visual impairment (4-14 years old) attempted all three visual field assessments. Full results were recorded for 91 per cent of children with SVOP, 87 per cent with Goldmann, and 100 per cent with confrontation SVOP was significantly faster than Goldmann (p < 0.001) and confrontation (p = 0.003). Thirty-five children with visual impairment (3-19 years old) with visual acuity ranging from 6/9.5 to worse than 6/360 (mean of 0.8 ± 0.4 logMAR) attempted SVOP, with 26 children able to complete SVOP.

DISCUSSION

This is the largest study to date of the clinical applicability of SVOP in children without visual impairment, as well as assessing the utility of SVOP in children with visual impairment. Further research is needed to assess the accuracy of SVOP in a range of paediatric ocular disorders. SVOP may potentially offer a visual field assessment method for children previously unable to complete current paediatric perimetry techniques.

A systematic review of game technologies for pediatric patients

Children in hospital are subjected to multiple negative stimuli that may hinder their development and social interactions. Although game technologies are thought to improve children's experience in hospital, there is a lack of information on how they can be used effectively. This paper presents a systematic review of the literature on the existing approaches in this context to identify gaps for future research. A total of 1305 studies were identified, of which 75 were thoroughly analyzed according to our review protocol. The results show that the most common approach is to design mono-user games with traditional computers or monitor-based video consoles, which serve as a distractor or a motivator for physical rehabilitation for primary school children undergoing fearful procedures such as venipuncture, or those suffering chronic, neurological, or traumatic diseases/injures. We conclude that, on the one hand, game technologies seem to present physical and psychological benefits to pediatric patients, but more research is needed on this. On the other hand, future designers of games for pediatric hospitalization should consider: 1. The development for kindergarten patients and adolescents, 2. Address the psychological impact caused by long-term hospitalization, 3. Use collaboration as an effective game strategy to reduce patient isolation, 4. Have purposes other than distraction, such as socialization, coping with emotions, or fostering physical mobility, 5. Include parents/caregivers and hospital staff in the game activities; and 6. Exploit new technological artifacts such as robots and tangible interactive elements to encourage intrinsic motivation.

Development of a Pediatric Visual Field Test

Purpose

We describe a pediatric visual field (VF) test based on a computer game where software and hardware combine to provide an enjoyable test experience.

Methods

The test software consists of a platform-based computer game presented to the central VF. A storyline was created around the game as was a structure surrounding the computer monitor to enhance patients' experience. The patient is asked to help the central character collect magic coins (stimuli). To collect these coins a series of obstacles need to be overcome. The test was presented on a Sony PVM-2541A monitor calibrated from a central midpoint with a Minolta CS-100 photometer placed at 50 cm. Measurements were performed at 15 locations on the screen and the contrast calculated. Retinal sensitivity was determined by modulating stimulus in size. To test the feasibility of the novel approach 20 patients (4–16 years old) with no history of VF defects were recruited.

Results

For the 14 subjects completing the study, 31 ± 15 data points were collected on 1 eye of each patient. Mean background luminance and stimulus contrast were 9.9 ± 0.3 cd/m² and 27.9 ± 0.1 dB, respectively. Sensitivity values obtained were similar to an adult population but variability was considerably higher – 8.3 ± 9.0 dB.

Conclusions

Preliminary data show the feasibility of a game-based VF test for pediatric use. Although the test was well accepted by the target population, test variability remained very high.

Translational Relevance

Traditional VF tests are not well tolerated by children. This study describes a child-friendly approach to test visual fields in the targeted population.

Normal Threshold Size of Stimuli in Children Using a Game-Based Visual Field Test

INTRODUCTION

The aim of this study was to demonstrate and explore the ability of novel game-based perimetry to establish normal visual field thresholds in children.

METHODS

One hundred and eighteen children (aged 8.0 ± 2.8 years old) with no history of visual field loss or significant medical history were recruited. Each child had one eye tested using a game-based visual field test 'Caspar's Castle' at four retinal locations 12.7° (N = 118) from fixation. Thresholds were established repeatedly using up/down staircase algorithms with stimuli of varying diameter (luminance 20 cd/m², duration 200 ms, background luminance 10 cd/m²). Relationships between threshold and age were determined along with measures of intra- and intersubject variability.

RESULTS

The Game-based visual field test was able to establish threshold estimates in the full range of children tested. Threshold size reduced with increasing age in children. Intrasubject variability and intersubject variability were inversely related to age in children.

CONCLUSIONS

Normal visual field thresholds were established for specific locations in children using a novel game-based visual field test. These could be used as a foundation for developing a game-based perimetry screening test for children.

Feasibility, Accuracy, and Repeatability of Suprathreshold Saccadic Vector Optokinetic Perimetry

Purpose

To evaluate feasibility, accuracy, and repeatability of suprathreshold Saccadic Vector Optokinetic Perimetry (SVOP) by comparison with Humphrey Field Analyzer (HFA) perimetry.

Methods

The subjects included children with suspected field defects (n = 10, age 5–15 years), adults with field defects (n = 33, age 39–78 years), healthy children (n = 12, age 6–14 years), and healthy adults (n = 30, age 16–61 years). The test protocol comprised repeat suprathreshold SVOP and HFA testing with the C-40 test pattern. Feasibility was assessed by protocol completeness. Sensitivity, specificity, and accuracy of SVOP was established by comparison with reliable HFA tests in two ways: (1) visual field pattern results (normal/abnormal), and (2) individual test point outcomes (seen/unseen). Repeatability of each test type was assessed using Cohen's kappa coefficient.

Results

Of subjects, 82% completed a full protocol. Poor reliability of HFA testing in child patients limited the robustness of comparisons in this group. Sensitivity, specificity, and accuracy across all groups when analyzing the visual field pattern results was 90.9%, 88.5%, and 89.0%, respectively, and was 69.1%, 96.9%, and 95.0%, respectively, when analyzing the individual test points. Cohen's kappa coefficient for repeatability of SVOP and HFA was excellent (0.87 and 0.88, respectively) when assessing visual field pattern results, and substantial (0.62 and 0.74, respectively) when assessing test point outcomes.

Conclusions

SVOP was accurate in this group of adults. Further studies are required to assess SVOP in child patient groups.

Translational Relevance

SVOP technology is still in its infancy but is used in a number of centers. It will undergo iterative improvements and this study provides a benchmark for future iterations.

Development and testing of an automated computer tablet-based method for self-testing of high and low contrast near visual acuity in ophthalmic patients

PURPOSE

Many eye diseases require on-going assessment for optimal management, creating an ever-increasing burden on patients and hospitals that could potentially be reduced through home vision monitoring. However, there is limited evidence for the utility of current applications and devices for this. To address this, we present a new automated, computer tablet-based method for self-testing near visual acuity (VA) for both high and low contrast targets. We report on its reliability and agreement with gold standard measures.

METHODS

The Mobile Assessment of Vision by intERactIve Computer (MAVERIC) system consists of a calibrated computer tablet housed in a bespoke viewing chamber. Purpose-built software automatically elicits touch-screen responses from subjects to measure their near VA for either low or high contrast acuity. Near high contrast acuity was measured using both the MAVERIC system and a near Landolt C chart in one eye for 81 patients and low contrast acuity using the MAVERIC system and a 25 % contrast near EDTRS chart in one eye of a separate 95 patients. The MAVERIC near acuity was also retested after 20 min to evaluate repeatability.

RESULTS

Repeatability of both high and low contrast MAVERIC acuity measures, and their agreement with the chart tests, was assessed using the Bland-Altman comparison method. One hundred and seventy-three patients (96 %) completed the self- testing MAVERIC system without formal assistance. The resulting MAVERIC vision demonstrated good repeatability and good agreement with the gold-standard near chart measures.

CONCLUSIONS

This study demonstrates the potential utility of the MAVERIC system for patients with ophthalmic disease to self-test their high and low contrast VA. The technique has a high degree of reliability and agreement with gold standard chart based measurements.

Study of Optimal Perimetric Testing in Children (OPTIC): Feasibility, Reliability and Repeatability of Perimetry in Children

Purpose

To investigate feasibility, reliability and repeatability of perimetry in children.

Methods

A prospective, observational study recruiting 154 children aged 5–15 years, without an ophthalmic condition that affects the visual field (controls), identified consecutively between May 2012 and November 2013 from hospital eye clinics. Perimetry was undertaken in a single sitting, with standardised protocols, in a randomised order using the Humphrey static (SITA 24–2 FAST), Goldmann and Octopus kinetic perimeters. Data collected included test duration, subjective experience and test quality (incorporating examiner ratings on comprehension of instructions, fatigue, response to visual and auditory stimuli, concentration and co-operation) to assess feasibility and reliability. Testing was repeated within 6 months to assess repeatability.

Results

Overall feasibility was very high (Goldmann=96.1%, Octopus=89% and Humphrey=100% completed the tests). Examiner rated reliability was ‘good’ in 125 (81.2%) children for Goldmann, 100 (64.9%) for Octopus and 98 (63.6%) for Humphrey perimetry. Goldmann perimetry was the most reliable method in children under 9 years of age. Reliability improved with increasing age (multinomial logistic regression (Goldmann, Octopus and Humphrey), p<0.001). No significant differences were found for any of the three test strategies when examining initial and follow-up data outputs (Bland-Altman plots, n=43), suggesting good test repeatability, although the sample size may preclude detection of a small learning effect.

Conclusions

Feasibility and reliability of formal perimetry in children improves with age. By the age of 9 years, all the strategies used here were highly feasible and reliable. Clinical assessment of the visual field is achievable in children as young as 5 years, and should be considered where visual field loss is suspected. Since Goldmann perimetry is the most effective strategy in children aged 5–8 years and this perimeter is no longer available, further research is required on a suitable alternative for this age group.

Perimetry in children: survey of current practices in the United Kingdom and Ireland

PURPOSE

Visual fields are key functional outcome measures in children with a variety of ophthalmologic disorders. However, reliably assessing fields in children is challenging. We report the findings of a survey of current practices of perimetry in children in the United Kingdom and Ireland.

METHODS

An electronic questionnaire was sent to Orthoptic Service Heads in July 2008. Respondents were asked for comments regarding visual field testing in children as well as details of the volume and type of perimetry performed in their units, over a 1-year period.

RESULTS

Of the 98 (62%) completed questionnaires, 16 departments reported not testing visual fields in children. In total 3675 subjects under 16 years of age were reported to have undergone perimetry in 1 year, most in units with a ≥ 50% pediatric caseload for orthoptics. A total of 42% of units used static perimetry alone, 11% kinetic, and 47% used a combination of both.

CONCLUSION

High numbers of visual field tests are carried out in children in the UK and Ireland annually. Automated perimetry is used predominantly, despite the underlying algorithms having been developed for adult populations. Thus there is a clear need for more research, to ensure that evolving management practices are informed by understanding of the diagnostic accuracy and value of perimetry in children.

A new perimeter using the preferential looking response to assess peripheral visual fields in young and developmentally delayed children

PURPOSE

To compare the sensitivity, specificity, and interpretability of a newly developed semiautomated static perimeter based on the preferential looking response to the results of confrontation visual field testing in a group of young and/or developmentally delayed children with and without visual field deficit.

METHODS

The preferential looking perimeter (PLP) uses observation of the child's natural eye movement response to an appearing target to determine the peripheral visual field. We compared preferential looking perimetry to confrontation testing in 74 children 3-10 years of age (mean, 6.6 years; median, 7 years), including 32 controls and 42 children with neurological and ocular disorders that could cause significant visual field deficit.

RESULTS

Using confrontation testing as the gold standard, the PLP was 100% sensitive and 100% specific (95% CI, 90%-100%), with excellent interobserver agreement. An interpretable result could be achieved in 15 (71%) of the 21 children in whom confrontation testing was unhelpful.

CONCLUSIONS

PLP is a useful new technique for assessing significant visual field loss in young or developmentally delayed children, with many advantages over confrontation testing.