Automated Measurement of Visual Acuity in Pediatric Ophthalmic Patients Using Principles of Game Design and Tablet Computers

Effect of different screen brightness and devices on online visual acuity test

PURPOSE

This study aimed to study the difference in test results of online visual acuity (VA) test under different devices and screen brightness conditions and to compare online VA test with Early Treatment Diabetic Retinopathy Study (ETDRS).

METHODS

Healthy volunteers with the best corrected VA of 0.0 LogMAR or higher were recruited. VAs under ETDRS were tested first, and then online VA test (the Stanford Acuity Test, StAT) visual acuities using iPad Air2 and Microsoft Surface pro4 under 50% and 100% screen brightness were performed. The VA results and the testing times were compared between different devices and screen brightness conditions.

RESULTS

A total of 101 eyes were included in this study. The VA results measured by the StAT were better than those of ETDRS. The VA results measured at 100% screen brightness were better than those of 50% brightness (mean difference, 0.013 logMAR at most, less than 1 letter); the VA results measured by iPad Air2 were better than those of Surface pro4 (mean difference, -0.009 logMAR at most, less than 1 letter). Significantly less time was spent on VA testing under StAT than that under ETDRS.

CONCLUSION

The impact of screen brightness and the device on the VA results generated by online VA tests was clinically insignificant. In addition, online VA tests are found to be reliable and more time efficient than ETDRS.

Development and Validation of a Digital (Peek) Near Visual Acuity Test for Clinical Practice, Community-Based Survey, and Research

Purpose

Unaddressed near vision impairment (NVI) affects more than 500 million people. Testing near vision is necessary to identify those in need of services. To make such testing readily accessible, we have developed and validated a new smartphone-based near visual acuity (NVA) test: Peek Near Vision (PeekNV).

Methods

Two forms of the PeekNV test were developed: (1) quantitative measurement of NVA, and (2) binary screening test for presence or absence of NVI. The validity study was carried out with 483 participants in Sagarmatha Choudhary Eye Hospital, Lahan, Nepal, using a conventional Tumbling "E" Near Point Vision Chart as the reference standard. Bland-Altman limits of agreement (LoA) were used to evaluate test agreement and test-retest repeatability. NVI screening was assessed using Cohen's kappa coefficient, sensitivity, and specificity.

Results

The mean difference between PeekNV and chart NVA results was 0.008 logMAR units (95% confidence interval [CI], -0.005 to 0.021) in right eye data, and the 95% LoA between PeekNV and chart testing were within 0.235 and -0.218 logMAR. As a NVI screening tool, the overall agreement between tests was 92.9% (κ = 0.85). The positive predictive value of PeekNV was 93.2% (95% CI, 89.6% to 96.9%), and the negative predictive value 92.7% (95% CI, 88.9% to 96.4%). PeekNV had a faster NVI screening time (11.6 seconds; 95% CI, 10.5 to 12.6) than the chart (14.9 seconds; 95% CI, 13.5 to 16.2; P < 0.001).

Conclusions

The PeekNV smartphone-based test produces rapid NVA test results, comparable to those of an accepted NV test.

Translational Relevance

PeekNV is a validated, reliable option for NV testing for use with smartphones or digital devices.

Development and validation of a new method for visual acuity assesment on tablet in pediatric population: eMOVA test

BACKGROUND

Amblyopia is a major public health concern. Its screening and management require reliable methods of visual acuity assessment. New technologies offer nowadays many tests available on different app stores for smartphone or tablet but most of them often lack of scientific validation for a medical use. The aim of our study was to attempt validating a tablet-based near visual acuity test adapted to the pediatric population: the eMOVA test (electronic Measurement Of Visual Acuity) by comparing visual acuity measured with more conventional test.

METHODS

A cohort of 100 children aged 3 to 8 attending the ophthalmic-pediatric for eye examination between September 2016 and June 2017 were included in the study. Near visual acuity was assessed on participants using both the eMOVA test and a Standard test (Rossano-Weiss test). Duration of each test, its comprehension, its acceptability and the attention of the child during the test was also investigated.

RESULTS

The eMOVA test overestimated near visual acuity by 0.06 logMAR. This difference, statistically significant, was not clinically relevant. The duration of the eMOVA test was longer than the reference test, but less discomfort and preferred by children and their parents compared to standard tests.

CONCLUSION

The eMOVA test appears as a reliable test to assess near visual acuity in children. By its portability and efficiency, this application proved to be a relevant tool to be used for children eye examination in daily routine at the hospital.

Visual Neuropsychology in Development: Anatomo-Functional Brain Mechanisms of Action/Perception Binding in Health and Disease

Vision is the main entrance for environmental input to the human brain. Even if vision is our most used sensory modality, its importance is not limited to environmental exploration. Rather it has strong links to motor competences, further extending to cognitive and social aspects of human life. These multifaceted relationships are particularly important in developmental age and become dramatically evident in presence of complex deficits originating from visual aberrancies. The present review summarizes the available neuropsychological evidence on the development of visual competences, with a particular focus on the associated visuo-motor integration skills in health and disease. With the aim of supporting future research and interventional settings, the goal of the present review is to constitute a solid base to help the translation of neuropsychological hypotheses into straightforward empirical investigations and rehabilitation/training protocols. This approach will further increase the impact, ameliorate the acceptance, and ease the use and implementation of lab-derived intervention protocols in real-life situations.

Evaluation of a New Method to Track Changes in Vision at Home for Children Undergoing Amblyopia Treatment

PURPOSE

A new amblyopia tracker app has been designed to provide parents with a method of monitoring a child's vision by presenting a single optotype size that the tester moves to identify the furthest distance the optotypes can be seen. The aim of this study is to evaluate this methodology in adults, comparing the findings to visual acuity (VA) measured with the iSight app and to determine the test retest variability.

METHODS

Adults, aged 18-39 years, with no known eye condition and VA ≤ 0.7 logMAR were recruited. Bangerter filters were used to simulate amblyopia, where VA was reduced below 0.0 with an interocular difference of at least 0.2 logMAR. Testing for both apps was performed monocularly, with the test order being randomised.

RESULTS

Data from 32 subjects were analysed. For the test retest variability analysis, paired t-tests showed no statistically significant difference between the tests for either eye, either app or the interocular acuity difference (p > 0.3 in all cases). Bland Altman plots showed similar limits of agreement between the two apps. When comparing measurements between the apps there was no statistically significant difference on the first or second test, either eye or the interocular acuity difference (p > 0.5 in all cases).

CONCLUSION

The results support the theory that changing distance is a valid method of assessing VA as the measurements agree well with the standard approach of reducing optotype size. Test retest variability is similar between the two apps and there is good agreement between the measurements.

A new visual acuity test on touchpad for vision screening in children

AIM

To validate a visual acuity (VA) test application on touchpad in the screening of pediatric population by comparing VA results obtained with conventional tests.

METHODS

A cohort of 101 patients, 44 girls and 57 boys with a median of 6.5 years old (3-10 years of age), presenting for eye examinations in Ophthalmology Department (Strasbourg, France) between November 1^st, 2018, and February 1^st, 2019 were enrolled. Monocular and binocular VA testing was performed on the subject using both a standard test and the touchpad application (Monoyer, "E" or, Pigassou depending of children's capacities). Patients were excluded if they were physically or mentally unable to use the touchpad. The duration of each tests, the painfulness, the comprehension, the attention of children during the test and test's preferences were also evaluated.

RESULTS

There was a good linear correlation and intra-class correlation coefficient [ICC=0.50 (0.34, 0.64) for binocular acuity, 0.74 (0.64, 0.82) for right eyes and 0.525 (0.37, 0.66) for left eye]. The standard errors of measurement were very low (0.08, 0.05, 0.08 for binocular VA, right eyes VA and left eyes VA, respectively). There was no difference between two tests for right eye (P=0.126), left eye (P=0.098) and binocular acuity (P=0.085). Non inferiority was proved for all binocular [-0.06 (-0.09, -0.03)], right eye [-0.04 (-0.07, -0.01)] and left eye [-0.06 (-0.09, -0.02)] VA. The sensitivity and specificity, which correspond to the ability for our app to detect amblyopia, were 92% and 80% respectively.

CONCLUSION

Our touchpad application represents an efficient and valid test of VA in children with a high specificity to detect visual impairment.

Impact of Children's Postural Variation on Viewing Distance and Estimated Visual Acuity

Purpose

Reliable estimation of visual acuity requires that observers maintain a constant distance from the target, but use of chin rests is not always feasible. Our aim was to quantify children's movement during community testing and its impact on near (40 cm) and intermediate (150 cm) acuity measures.

Methods

Thirty-three 7-year-old children performed several acuity tests run on a tablet computer, administered in the child's home by a trained lay screener. The tablet webcam was used to derive a continuous estimate of the child's position during testing. We estimated acuity using both the recommended viewing distance and using trial-by-trial estimates of the child's physical distance from the screen.

Results

Although initial positioning in the 40-cm viewing distance condition was accurate, on 18% of trials children moved sufficiently to support a 0.1 logMAR improvement in acuity, leading 16% of staircases to overestimate acuity by more than one line. Initial positioning for the 150-cm condition was less accurate, but the longer viewing distance minimized the impact of children's movement on the visual angle of the target. Overall, at 150 cm 8% of staircases were overestimated by more than 0.1 logMAR.

Conclusions

Children move substantially during intermediate and near acuity tests despite assessors encouraging maintenance of the correct viewing distance.

Translational Relevance

Real-time estimates of the child's physical distance from the target are possible when assessments are conducted on camera-enabled devices. Correction for movement will likely lead to more accurate measures of near and intermediate visual acuity.

Recognition acuity in children measured using The Auckland Optotypes

PURPOSE

Sloan letters displayed by the Electronic Visual Acuity (EVA) system are the gold standard for recognition acuity measurement in research settings. However, letters are not always appropriate for children. The Auckland Optotypes (TAO) are a new, open-access set of 10 pictograms available in regular and vanishing formats. We sought to assess feasibility of using both formats of TAO for measuring visual acuity (VA) in children using a Bayesian adaptive staircase, in a community setting.

METHODS

We tested 121 children (5-12 years old) with both formats of TAO, a handheld flipchart vision screener (Parr vision test), as well as the gold standard EVA. We measured feasibility of the three comparison tests in three ways. First, using limits of agreement (LoA) with EVA, second, calculating area under the receiver operating characteristic curve (AUC), and finally, investigating trial-by-trial responses.

RESULTS

Agreement between tests was within test-retest reliability of EVA measures (LoA_{TAO regular}  = ±0.14, LoA_{TAO vanishing}  = ±0.15, LoA_{P arr}  = ±0.16 logMAR). TAO tests were highly effective at identifying children with vision impairment (AUC_{TAO regular}  = 0.96, AUC_{TAO vanishing}  = 0.95), whereas Parr was less effective (AUC_{P arr}  = 0.82). In 5-6 year old children there was an enhanced advantage of TAO (AUC_{TAO regular}  = 0.97, AUC_{TAO vanishing}  = 0.98) over Parr (AUC_{P arr}  = 0.75). Although each child completed 16 trials, approximately 10 trials were sufficient to achieve excellent LoA, and six trials sufficient for accurate screening.

CONCLUSION

Threshold VA assessment and vision screening are feasible using both vanishing and regular formats of TAO.

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.