The measurement of visual acuity in children: an evidence‐based update

Postoperative outcome and influencing factors of strabismus surgery in infants aged 1-6 years

PURPOSE

To evaluate the postoperative outcome of strabismus surgery performed in children aged 1-6 years by investigating the change of the preoperative angle of deviation (AOD), elevation in adduction, best-corrected visual acuity (BCVA) and refractive error.

METHODS

Retrospective chart review of 62 children who received strabismus surgery between January 2018 and December 2021 at the Department of Ophthalmology and Optometry of the Medical University of Vienna. Age, sex, type of strabismus, AOD, BCVA, refractive error and visual acuity were evaluated with respect to the postoperative outcome.

RESULTS

Mean follow-up was 13.55 ± 11.38 months with a mean age of 3.94 ± 1.97 years (range: 1.0-6.0) at time of surgery. 74.19% of patients (n = 46) had isolated or combined esotropia, 12.90% (n = 8) had isolated or combined exotropia and 12.90% (n = 8) had isolated strabismus sursoadductorius. Mean preoperative AOD of 15.69 ± 16.91°/15.02 ± 14.88° (near/distance) decreased to 4.00 ± 9.18°/4.83 ± 7.32° (near/distance) at final follow-up (p < 0.001). BCVA improved from 0.26 ± 0.26/0.25 ± 0.23 (left/right) to 0.21 ± 0.25/0.20 ± 0.23 (left/right) (p = 0.038). There was no significant change regarding refractive error (p = 0.109) or elevation in adduction (p = 0.212). Success rate which was defined as a residual AOD of less than 10° was 74.19% (n = 46). In 3.23% (n = 2) retreatment was necessary.

CONCLUSION

Strabismus surgery in infants was shown to have a satisfactory outcome with a low retreatment rate. Surgical success rate was not linked to age, sex, type of strabismus or the preoperative parameters AOD, refractive error and visual acuity in this study.

Managing the apparently blind child presenting in the first year of life: A review

Severe vision impairment and blindness in childhood have a significant health burden on the child, family and society. This review article seeks to provide a structured framework for managing the apparently blind child presenting in the first year of life, starting from a comprehensive history and examination. Different investigation modalities and the increasingly important role of genetics will also be described, in addition to common causes of severe vision impairment. Crucially, a systematic approach to the blind infant is key to correct diagnoses and timely management. Incorrect diagnoses can be costly to all involved, however it is important to note that diagnoses can change with ongoing follow-up and investigations. Furthermore, the modern age of ophthalmology requires a multi-disciplinary approach and close collaboration with specialists including paediatricians, neurologists and geneticists, in addition to rehabilitation and low vision services, to ensure the best care for these vulnerable infants.

The Freiburg Acuity Test in Preschool Children: Testability, Test-Retest Variability, and Comparison With LEA Symbols

Purpose

To determine the testability, performance, and test-retest variability (TRV) of visual acuity (VA) assessment using the Freiburg Visual Acuity Test (FrACT) compared to the LEA Symbols Test (LEA) in preschool children.

Methods

In 134 preschool children aged 3.0 to 6.8 years, monocular VA of each eye was measured twice with a four-orientation Landolt C version of the FrACT and once with the LEA. FrACT runs were preceded by a binocular run for explanatory purposes. Test order alternated between subjects. Optotypes were presented on a computer monitor (FrACT) or on cards (LEA) at a distance of 3 m.

Results

Overall, 68% completed the FrACT (91/134 children) and 88% completed the LEA (118/134 children). Testability depended on age: FrACT, 19% (<4 years) and 87% (≥4 years); LEA, 70% (<4 years) and 95% (≥4 years). Mean ± SD VA difference between tests was 0.11 ± 0.19 logarithm of the minimum angle of resolution [logMAR], with LEA reporting better acuity. The difference depended on age (0.27 ± 0.23 logMAR [<4 years], 0.09 ± 0.18 logMAR [≥4 years], P < 0.001) and on test sequence (higher age dependence of FrACT VAs for LEA first, P < 0.001). The 95% limits of agreement for the FrACT TRV were ±0.298 logMAR.

Conclusions

The examiner-independent FrACT, using international reference Landolt C optotypes, can be used to assess VA in preschool children aged ≥4 years, with reliability comparable to other pediatric VA tests.

Translational Relevance

Use of the automated FrACT for VA assessment in preschool children may benefit objectivity and validity as it is a computerized test and employs the international reference Landolt C optotype.

Trends in Volume and Charges of Retinal Tear Patients in the Emergency Department

PURPOSE

To characterize retinal tears (RTs) and calculate the economic burden of RTs that present to the emergency department (ED) in the US.

METHODS

We used a large national ED database to retrospectively analyze RTs that presented to the ED from 2006 to 2019. Using extrapolation methods, national of the RT patient ED volume, demographics, comorbidities, disposition, inpatient (IP) charges, and ED charges were calculated.

RESULTS

During the period between 2006 and 2019, 15841 ED encounters had RT listed as the primary diagnosis. The average annual RT ED encounters was 2,640 ± 856 and comprised an average of 6.4 × 10 - 5 % of all ED visits annually. The number and ED percentage of RT encounters did not change during this time period (p = .22, p = .67, respectively). Most patients were males, Caucasian, paid with private insurance, and admitted to EDs in the Northeast. The most common comorbidities were hypertension (19%), a history of cataracts (15%), and diabetes (7.2%). During this time period, RTs charges added up to more than $79 million and $33 million in the ED and IP settings, respectively. Mean per-encounter ED and IP charges increased by 145% (p = .0008) and 86% (p = .0047), respectively.

CONCLUSION

Despite the stable number of RT patients presenting to the ED, RTs place a significant economic burden to the healthcare system, which increases yearly. We recommend physicians and policy makers to work together to pass laws that could prevent the increasing healthcare charges.

Inter-Rater Reliability of EyeSpy Mobile for Pediatric Visual Acuity Assessments by Parent Volunteers

Purpose

To assess the inter-rater test reliability of the EyeSpy Mobile visual acuity smartphone algorithm when administered to children by eye professionals and parent volunteers.

Patients and Methods

Visual acuity test-retest results were analyzed for 106 children assigned to one of three different screenings: (1) An eye technician and pediatric ophthalmologist using their typical visual acuity testing method on a M&S computer; (2) An eye technician and pediatric ophthalmologist using EyeSpy Mobile; (3) An eye technician and parent volunteer using EyeSpy Mobile.

Results

All three phases demonstrated a strong agreement between the two testers, with mean test-retest equivalency results within 0.05 logMAR (2.5 letters, 90% CI). Whether testing using their typical technique on an M&S computer or using EyeSpy Mobile, eye professionals obtained statistically closer mean test-retest results than parent volunteers by 1 letter, with equivalency results within 0.03 logMAR (1.5 letters, 90% CI). Conversely, the number of retests within 2 vision lines was statistically greater when EyeSpy mobile was used by parents as compared to eye professional's customary technique on the M&S computer.

Conclusion

EyeSpy Mobile provides clinically useful visual acuity test-retest results even when used by first-time parent volunteers. Adaptive visual acuity algorithms have the potential to improve reliability, lessen training requirements, and expand the number of vision screening volunteers in community settings.

Visual acuity and reading print size requirements in children with vision impairment

CLINICAL RELEVANCE

The support of students with a vision impairment throughout education could be enhanced by assessing the functional reading ability of the individual. This visual assessment could inform educators of individualised student needs and potentially improve the academic achievement for these students.

BACKGROUND

Support for children with a vision impairment within a classroom is typically based on clinical findings of distance visual acuity and visual fields. Therefore, determining optimal print size for reading is essential to ensure best academic outcomes. Secondary aims were to investigate the possible impact of underlying pathology on reading ability.

METHODS

Forty-seven participants were recruited from a state-wide support service for children with a vision impairment in South Australia. Three visual acuity groups were formed based on World Health Organisation definitions of mild, moderate, and severe vision impairment. Correlation between clinical measures of distance visual acuity using the Freiburg Visual Acuity Test, were compared with reading acuity and critical print size (smallest font before reading speed reduced) using Minnesota low vision reading chart (MNREAD).

RESULTS

No significant correlations were found for mild (0.20-0.49 logMAR) and severe (1.00-1.52 logMAR) vision impairment groups between distance visual acuity and reading acuity read (p = .64, CI [-.585, .395]/p = .82, CI [-.48, .58]) or critical print size (p = .78, CI [-.57, .45]/p = .43, CI [-.34, .68]. A significant correlation was found for the moderate vision impairment group: 0.50-0.99 logMAR for minimum reading acuity (p < .001, CI [.44, .91]) and critical print size (p = .03, CI [.05, .80]).

CONCLUSIONS

Standard clinical measures of distance visual acuity are an unpredictable estimate of reading ability in children with mild and severe vision impairment. Additional measures of functional near reading ability could provide a more meaningful indicator of reading ability and help provide optimum support to students through education.

Measuring recognition visual acuity in young children - testability with the Waterloo Differential Acuity Test (WatDAT)

CLINICAL RELEVANCE

Visual acuity measurement is important for the detection and monitoring of eye disorders. Developing accurate and sensitive visual acuity tests suitable for young children is therefore desirable.

BACKGROUND

Recognition or form visual acuity (VA), which is measured with matching in children aged 3 years and up, is more sensitive for detecting visual deficits compared to resolution VA. The Waterloo Differential Acuity Test (WatDAT) is a proposed recognition VA test using the concept of identifying the "odd one out" among distractors. The WatDAT is expected to be cognitively easier than matching tests and therefore may be used in younger children. The purpose of this study is to investigate the testability of the WatDAT paradigm in children aged 12-36 months, and to determine the optimum format and number of distractors.

METHODS

Fifty-one typically-developing children aged 12-36 months participated in the study. Data for Patti Pics (PP) and Face targets (FT) were collected for formats with 3, 4 and 5 distractors. The targets were presented binocularly on a computer touch screen at 30 cm. The task was to touch the face among identical non-faces or a house among circles. Following initial training, there were 5 presentations for each distractor format. Testability was defined as correctly identifying at least 4/5 presentations and was also determined for uncrowded PP symbols using matching.

RESULTS

Of participants aged 18-36 months, 87% could perform the WatDAT PP targets with 3 distractors compared to 68% for the FT, while 48% could perform matching with PP. The testability for FT increased to 85% for children ≥22 months. Younger children showed lower testability. For the 3 distractor format, PP targets gave 9% testability in children 12 to <18 months, and FT gave a testability of 16% in children 12 to <22 months.

CONCLUSION

WatDAT testability is higher than matching VA tests. This indicates that the newly developed WatDAT has potential for measuring recognition VA in children 18 months and older.

Measures and variability with age of low contrast acuity and near stereoacuity in children

CLINICAL RELEVANCE

Low contrast acuity (LCA) and near stereoacuity (NS) testing are integral to the comprehensive assessment of sensory visual function in children. However, routine ophthalmological evaluations seldom take these measures into consideration. Additionally, there is limited literature regarding the normative values of these parameters in children.

BACKGROUND

This study investigated LCA and NS measures and their variability in children with normal visual acuity. The aim was to provide a benchmark for distinguishing normal measures from abnormal ones.

METHODS

A prospective observational study was conducted in primary and secondary schools across North India. The participants numbered 240 children, aged between 3 and 15 years. They were split into 12 smaller groups of 20 participants in each age group. Only participants with normal monocular uncorrected visual acuity, no refractive error, normal birth history, and no systemic ailments, were recruited. All the participants underwent a complete ophthalmic examination and non-cycloplegic retinoscopy. LCA was measured, using the low contrast Lea number chart at three metres. NS was measured using the Randot® stereo test at 40 cm.

RESULTS

The percentages of males and females, were found to be 55%, and 45%, respectively (p = 0.093). The mean NS was found to be 38.7 ± 11.5 arcsecs in the 3-9-year age group, and 26.7 ± 5.6 arcsecs in the 9-15-year age group (p-value <0.001). The mean NS showed an increasing trend up to 9 years of age. The mean LCA was 64.4 ± 20.1 in the age group of 3-8 years, and 76.38 ± 11.39 in the age group of 8-15 years (p-value <0.001). Considerable variability was noted in the LCA in the younger age group (p-value = 0.000).

CONCLUSIONS

LCA and NS mature gradually during childhood. LCA stabilises after the age of 8, while NS stabilises after the age of 9.

Discrimination of paediatric acuity test optotypes by 6-year-old children

PURPOSE

To compare the discrimination performance of 6-year-old children for optotypes from six paediatric visual acuity tests and to fit Luce's Biased Choice Model to the data to estimate the relative similarities and bias for each optotype.

METHODS

Full data sets were collected from 20 typically developing 6-year-olds who had passed a vision screening. They were presented with single optotypes labelled 6/12 at a distance of 9 m and were asked to identify the optotype using a matching task containing all optotypes from the relevant test. The data were combined to form a confusion matrix for each test and a biased choice model was fitted to the data.

RESULTS

Median correct performance varied from 40% to 100% across optotypes, with the HOTV test having the highest values. Estimates of the similarity of each pair of optotypes indicated equal values for all pairs in the Landolt C, HOTV, Lea numbers and Tumbling E tests. The values differed for the picture tests, that is Lea Symbols and Allen figures. The estimates of bias for each individual optotype also indicated different values with the picture tests.

CONCLUSIONS

Previous studies of the threshold acuity of young children and adults have indicated differences in acuity estimates across paediatric tests. A recognition acuity task typically requires resolving the difference information between optotypes. The performance of the 6-year-olds here reveals variance in similarity and bias values for picture tests, particularly for the Allen figures when compared with the Lea Symbols. Ideally, this analysis should be performed when designing new tests, and these results motivate progression from the use of current picture tests to well calibrated letter or number tests at the earliest possible age.

Paediatric cataract surgery with 27G vitrectomy instrumentation: the Ghent University Hospital Experience

Objective

To describe a cohort of paediatric patients who underwent unilateral or bilateral lens extractions at Ghent University hospital using the Dutch Ophthalmic Research Center (D.O.R.C.) ultra-short 27G vitrectomy system.

Methods

Retrospective analysis of the medical and surgical records of all children that underwent lens extraction between September 2016 and September 2020 using the D.O.R.C. ultra-short 27G vitrectomy system.

Results

Seventy-two eyes of 52 patients were included. The most important aetiologies in this study were of secondary (25.5%), developmental (13.7%), or genetic (13.7%) nature. No definitive cause could be established in more than a quarter of cases (27.5%) despite extensive work-up, them being deemed idiopathic. The remainder of cases (19.6%) was not assigned a final aetiologic designation at the time of the study due to contradicting or missing diagnostic data. This study could not identify any cataract cases related to infection or trauma. Surgical complications rate was 61.1% of which posterior capsule opacification was the most frequent with a rate of 25%. A significant short-term postoperative best-corrected visual acuity gain (≤ -0.2 LogMAR) was observed in 60.5% of eyes for which usable acuity data were available (n = 38).

Conclusion

Many different instruments and techniques have been described and used in the context of paediatric lens extractions, each with its advantages and disadvantages. This study illustrates that an ultra-short 27G vitrectomy system can be used to perform paediatric lens extractions with good surgical outcomes. Further studies and comparative trials are needed to ascertain this further.

OKN-Fast: Objective visual acuity threshold measurement using the optokinetic response. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023;2023:1-4. [PMID: 38083632 DOI: 10.1109/embc40787.2023.10340573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Visual acuity (VA) is the gold-standard measure for the assessment of visual function, but it is challenging to obtain in non-verbal adults and young children. We present OKN-Fast, an objective, automated method for estimation of VA using a reflexive eye movement called optokinetic nystagmus (OKN) that does not require a verbal response from the patient (VA-OKN). We tested the method in a cohort of healthy adults (n=12) with good vision, who were also blurred using a lens. On average OKN-Fast reduced the number of trials needed to determine threshold by half, as compared to a gold standard trial-by-trial assessment. The VAs determined by OKN and ETDRS were similar when blurred (no statistically significant difference). However, a significant bias of logMAR 0.2 was observed for the good vision condition. VA-OKN was highly repeatable with limits of agreement (LOA) similar to those found for ETDRS charts when blurred. However, this VA-OKN was only moderately correlated with VA measured using a ETDRS chart (r2 = 0.55). These results suggest that further optimization is warranted.Clinical Relevance- This work provides an automated approach for the estimation of visual acuity in non-verbal populations such as young children or non-verbal adults.

Characteristics and Related Parameters of Quick Contrast Sensitivity Function in Chinese Ametropia Children

PURPOSE

To investigate the characteristics of quick contrast sensitivity function (qCSF) and its related parameters in Chinese ametropia children.

METHODS

This case series study enrolled 106 eyes of 53 children (male/female=29/24, age: 9.04±2.06 years). Examinations included manifest refraction, axial length, corneal curvature, and monocular and binocular qCSF readings without refractive correction (area under log CSF [AULCSF], CSF acuity, and contrast sensitivity [CS] at 1.0 to 18.0 cpd). The subjects were divided into groups according to age and refractive parameters for analysis.

RESULTS

The mean spherical equivalent (SE), AULCSF, and CSF acuity of the test eyes were -0.94±1.53 D, 0.44±0.33, and 8.50±5.97 cpd, respectively. In the monocular qCSF comparison, the refraction sphere (RS) was the major factor correlated with qCSF readings (B=0.186, P =0.009 for AULCSF; B=0.543, P =0.019 for CSF acuity; generalized linear model). The three groups stratified by RS/SE (<-1.00D, -1.00D to 0D, and >0D) showed significant differences in CS at medium spatial frequencies (3.0 and 6.0 cpd; all P <0.05). In the low RS/SE group (within -1 to 0 D), the CS at 12.0 cpd was significantly lower than that in the hyperopia group (all P <0.05). Binocular qCSF readings were significantly correlated with those of the eyes with lower RS (all P <0.05).

CONCLUSION

RS and SE are the major contributing factors of qCSF without refractive correction in children. The CS at medium spatial frequencies decrease significantly as the RS/SE increase. In low myopia children, the CS at medium and high spatial frequencies are significantly decreased, providing practical value in visual function screening in children.

PandAcuity in paediatrics: a novel clinical measure of visual function based on the panda illusion

BACKGROUND/AIMS

To evaluate the PandAcuity test for visual function testing in a paediatric cohort and to examine its agreement with conventional visual acuity (VA) testing.

METHODS

PandAcuity scores were determined in 152 children (77 males) aged between 3 and 15 years after VA testing (LEA^TM-test, E-chart, Landolt-C-rings or numbers). The PandAcuity test consisted of illusions made up from silhouettes of animals 'hidden' within zig-zag-patterns of decreasing spatial frequencies. Correlation analyses between PandAcuity score and VA were performed.

RESULTS

150 children completed the test in at least one eye, 148 in both eyes. The PandAcuity test demonstrated good test-retest reliability (intraclass correlation coefficient=0.89) between two runs. VA and PandAcuity score showed a medium to large correlation (Spearman's ρ=0.52, p<0.0001). 93% of the children's visual impairment was classified in the same range by both test types. Receiver operating characteristic analysis of predicted visual impairment showed an excellent agreement with the classification based on VA testing (AUC=0.84).

CONCLUSION

The PandAcuity test is rapid, simple and well accepted, rendering it a suitable supplement for the clinical assessment of VA in children. Because of its counterintuitive application (a higher number of correctly identified images means worse VA), it can be used to cross-validate conventional acuity tests to assure children's compliance.

Worsening vision at age 4-5 in England post-COVID: Evidence from a large database of vision screening data

PURPOSE

Myopia prevalence has increased in the UK at age 10-16y, but little is known about younger children. We hypothesise that if the 'myopia epidemic' is affecting young children, then there will be increasing rates of bilateral reduced unaided vision (V) at vision screenings of children 4-5 years of age.

METHODS

Retrospective anonymised data from computerised vision screening at age 4-5 years were analysed from serial cross-sectional data. Refractive error is not assessed in UK vision screening, so vision was investigated. Data were only included from schools that screened every year from 2015/16 to 2021/22. The criterion used was unaided monocular logMAR (automated letter-by-letter scoring) vision >0.20 in both the right and left eyes, so as to maximise the chances of detecting bilateral, moderate myopia rather than amblyopia.

RESULTS

Anonymised raw data were obtained for 359,634 screening episodes from 2075 schools. Once schools were excluded where data were not available for every year and data were cleaned, the final database comprised 110,076 episodes. The proportion (percentage and 95% CI) failing the criterion from 2015/16 to 2021/22 were 7.6 (7.2-8.0), 8.5 (8.1-8.9), 7.5 (7.1-7.9), 7.8 (7.4-8.2), 8.7 (8.1-9.2), 8.5 (7.9-9.0) and 9.3 (8.8-9.7), respectively. The slope of the regression line showed a trend for increasing rates of reduced bilateral unaided vision, consistent with increasing frequency of myopia (p = 0.06). A decreasing linear trendline was noted for children 'Under Professional Care'.

CONCLUSIONS

For children 4-5 years of age, there were signs of reduced vision over the last 7 years in England. Consideration of the most likely causes support the hypothesis of increasing myopia. The increase in screening failures highlights the importance of eye care in this young population.

Spatial Resolution Evaluation Based on Experienced Visual Categories With Sweep Evoked Periodic EEG Activity

Purpose

Visual function is typically evaluated in clinical settings with visual acuity (VA), a test requiring to behaviorally match or name optotypes such as tumbling E or Snellen letters. The ability to recognize these symbols has little in common with the automatic and rapid visual recognition of socially important stimuli in real life. Here we use sweep visual evoked potentials to assess spatial resolution objectively based on the recognition of human faces and written words.

Methods

To this end, we tested unfamiliar face individuation1 and visual word recognition2 in 15 normally sighted adult volunteers with a 68-electrode electroencephalogram system.

Results

Unlike previous measures of low-level visual function including VA, the most sensitive electrode was found at an electrode different from Oz in a majority of participants. Thresholds until which faces and words could be recognized were evaluated at the most sensitive electrode defined individually for each participant. Word recognition thresholds corresponded with the VA level expected from normally sighted participants, and even a VA significantly higher than expected from normally sighted individuals for a few participants.

Conclusions

Spatial resolution can be evaluated based on high-level stimuli encountered in day-to-day life, such as faces or written words with sweep visual evoked potentials.

The influence of congenital corneal opacity on ERGs obtained using an abbreviated protocol

BACKGROUND

Visual electrophysiology may be used to assess visual potential in infants with congenital corneal opacities (CCO). It is essential to recognize confounding effects from these opacities on the flash electroretinogram (ERG).

METHODS

ERGs were recorded in awake children employing skin electrodes placed at the lower eyelid crease, both referred to a midfrontal electrode (Fz). A hand-held stimulator was used to present a mixed rod-cone and a dim white stimulus. Recordings were carried out before and after penetrating keratoplasty (PK), when performed.

RESULTS

Five infants under the age of 12 months with visually significant CCO were evaluated. In all cases, initial ERGs employing the mixed rod-cone stimulus showed well-defined a-wave with reduced amplitude b-wave. Reduction of stimulus intensity resulted in an increase in the b-wave and normalization of the b:a ratio from 1.1 (range 0.7 to 1.3) to 2.8 (range 1.5 to 4.3). In three cases who underwent PK, the postoperative ERGs recorded with a mixed rod-cone stimulus were normal in waveform shape with a mean b:a ratio of 2.0 (range 1.7 to 3.0).

CONCLUSION

Selective reduction of the scotopic bright flash ERG b-wave is typically caused by retinal dysfunction that is post-phototransduction or inner retinal. In infants with CCO, scotopic ERGs to bright flashes can show a reduced b:a ratio that improves or normalizes either after PK or stimulus intensity reduction. The study highlights that media opacity can contribute to the generation of an ERG with reduced b-wave in the absence of inner retinal dysfunction.

Agreement between Lea Symbols and Patti Pics visual acuity in children and adults

BACKGROUND

Patti Pics (PP) and Lea Symbols (LS) are commonly used by eye care practitioners worldwide. Although the relationship between the two tests is fairly well understood, the availability of different chart designs (single optotypes, multiple optotypes, multiple optotypes with crowding box) merits futher understanding. The purpose of this study is to explore the agreement between the acuity measures obtained with Patti Pics and Lea Symbols in children and adults and compare their performance with the Sloan Letter (SL) chart in adults.

METHODS

Monocular visual acuity was obtained from ninety-three 3 to 5-year-old children using Patti Pics and Lea Symbols. Acuities were also obtained from 113 adults using the same tests under identical conditions. Acuity results obtained with the pediatric tests were compared with the gold-standard Sloan Letter chart in adults. The Bland-Altman method was implemented to compare the level of agreement between tests.

RESULTS

Patti Pics yielded worse visual acuity than the Lea Symbols by approximately half a logMAR line in both children (mean difference: -0.07 ± 0.07 logMAR, p <0.01) and adults (Mean difference: -0.05 ± 0.06 logMAR, p <0.01). The 95% limits of agreement between Lea Symbol acuity and Patti pics acuity in children was ± 0.14 logMAR. Mean difference between the Sloan Letter chart and Lea Symbols acuity was not statistically significant (p = 0.08) in adults but the difference was statistically significant between PP and SL (p<0.001). The 95% limits of agreement between LS and SL and between PP and SL was ± 0.19 logMAR and ± 0.22 logMAR, respectively.

CONCLUSION

Patti Pics consistently underestimated visual acuity as compared to Lea Symbols both in children and adults although the differences were not clinically significant. The LS and PP did not yield clinically significant differences in acuities when compared with Sloan letters in adults.

Visual Acuity and Contrast Sensitivity in Preterm and Full-Term Children Using a Novel Digital Test

Visual assessment in preverbal children mostly relies on the preferential looking paradigm. It requires an experienced observer to interpret the child's responses to a stimulus. DIVE (Device for an Integral Visual Examination) is a digital tool with an integrated eye tracker (ET) that lifts this requirement and automatizes this process. The aim of our study was to assess the development of two visual functions, visual acuity (VA) and contrast sensitivity (CS), with DIVE, in a large sample of children from 6 months to 14 years (y) of age, and to compare the results of preterm and full-term children. Participants were recruited in clinical settings from five countries. There were 2208 children tested, 609 of them were born preterm. Both VA and CS improved throughout childhood, with the maximum increase during the first 5 years of age. Gestational age, refractive error and age had an impact on VA results, while CS values were only influenced by age. With this study we report normative reference outcomes for VA and CS throughout childhood and validate the DIVE tests as a useful tool to measure basic visual functions in children.

Real-World Application of Home Visual Acuity Testing for Pediatric Teleophthalmology During the COVID-19 Pandemic

PURPOSE

To review the ability of home visual acuity testing during teleophthalmology consultations to accurately assess visual acuity in pediatric patients in a real-world setting.

METHODS

This was a retrospective study of pediatric patients who were examined via teleophthalmology consultation due to the coronavirus disease 2019 (COVID-19) pandemic-related community restrictions between May and June 2020 at a single private ophthalmology practice. Home visual acuity findings were compared with the subsequent in-person assessment to determine agreement between measures.

RESULTS

Forty-three patients (86 eyes) were included in the study. The mean patient age at the time of teleophthalmology assessment was 75.9 months (range: 29 to 173 months). The correlation between home visual acuity findings and subsequent in-person assessment across all participants was 0.56 (P < .001). The upper and lower limits of agreement were 0.38 logarithm of the minimum angle of resolution (logMAR) units and -0.33 logMAR. The correlation reduced to 0.46 (P = .013) in patients younger than 5 years and increased to 0.70 (P < .001) in patients 8 years and older.

CONCLUSIONS

Home visual acuity assessment for teleophthalmology is of increased clinical value in older pediatric patients. In-person assessment by a trained clinician is the optimal method to determine visual acuity. Because home visual acuity assessment may be necessitated by local and global factors, further research is required regarding the optimal methods for assessment, particularly in younger patients. [J Pediatr Ophthalmol Strabismus. 2022;59(5):296-302.].

Using a Computerised Staircase and Incremental Optotype Sizes to Improve Visual Acuity Assessment Accuracy

Background:

Given the impact of visual acuity results on diagnosis and management, it is essential that the test is accurate, determined by factors such as test-retest variability. Standardisation improves accuracy, which can be performed via a computerised staircase methodology. Standard clinical tests with scoring of 0.02 per optotype implies an incremental score per optotype despite optotype size remaining constant on each line. The aim of this study is to establish if near continuous incremental optotype display and scoring improves test-retest variability compared to current testing methods.

Methods:

A computerised three up, one down adaptive staircase was used to display Kay Picture optotypes on an LCD monitor. Three methods of visual acuity assessment were undertaken: ETDRS, Kay Pictures and computerised Kay Pictures. Tests were performed twice under standard clinical conditions.

Results:

One hundred nineteen adults were tested. Test-retest variability for computerised Kay pictures was 0.01 logMAR (±0.04, p = 0.001). Good levels of agreement were observed for computerised Kay pictures in terms of test-retest variability, where the test had the smallest mean bias (0.01 logMAR compared to 0.03 and 0.08 logMAR for Kay Pictures and ETDRS respectively) and narrowest limits of agreement. Participants performed better in computerised Kay pictures than Kay Pictures by 0.03 logMAR, and better in ETDRS than computerised Kay pictures by 0.1 logMAR.

Conclusion:

Computerised Kay pictures exhibited a low test-retest variability, demonstrating it is reliable and repeatable. This repeatability measure is lower than the test-retest variability of the ETDRS and Kay Pictures tests.

The Effect of Test Method on Visual Acuity in School Children Aged 4–5

Purpose:

This study compared two different methods of testing visual acuity (VA) in children aged 4–5 years (The UK’s school vision screening target age). A conventional vision test method was compared to a reversed presentation order of logMAR, where letters are presented in ascending size order up to vision threshold. Threshold VA, test duration and concentration were compared, to assess the most accurate and efficient method of VA testing in this age group, to determine the most clinically and cost-effective method for vision screening.

Methods:

Thirty-four participants completed the study (15 males, 19 females, age range 53–65 months, mean age 59 months’ ±3.7 months). VA was measured in logMAR. Keeler Crowded logMAR screening plates determined the starting line on the vision chart to ensure the initial optotype size was either seen or not seen for the conventional and reversed test methods respectively. Test duration was measured in seconds and a concentration score was given by the examiner.

Results:

The median VA was 0.17 logMAR for each test method. There was no significant difference in the VA outcomes between each test method (p = 0.46). The reversed method was significantly quicker to complete, with a median reduction in test duration of 28 seconds (p = 0.002). There was no difference in concentration levels between the test methods.

Conclusion:

Both test methods gave the same VA threshold, and are therefore comparable. The reversed method was significantly quicker to complete which could benefit school vision screening services and busy clinical contexts.

Evaluation of the Blinq Vision Screener in the Detection of Amblyopia and Strabismus in Children

Purpose

Amblyopia is a major health problem with an estimated 2% to 4% of the population affected. Screening combined with corrective measures, such as correction of refractive error and occlusion of the dominant eye, could reduce this prevalence. A new pediatric vision scanner, the blinq (Rebion, Boston, MA), studies the foveolar quality of fixation of each eye during binocular viewing. Based on the initial premise that poor quality foveolar or non-foveolar fixation is indicative of strabismus and, potentially of amblyopia, this study evaluates the effectiveness of the blinq screening device in detecting these two conditions compared to a standard ophthalmic examination (Gold Standard) based on the recommendations of the American Association for Pediatric Ophthalmology and Strabismus.

Material and Methods

A prospective study was performed on a total of 101 children between 2 and 8 years of age. These children were offered a test by the blinq screening device before a standard ophthalmological examination in the ophthalmology department of the Erasmus Hospital in Brussels, Belgium. The two tests were then compared.

Results

In a pediatric population heightened with amblyopia and strabismus (prevalence of 33.4%) and based on the Gold Standard Examination, the blinq device showed a specificity of 73.1% (95% confidence interval [CI] = 60.9%–83.2%) with a sensitivity of 91.2% (95% CI = 76.3%–98.1) to detect these conditions. The positive and negative predictive values were 63.3% (95% CI = 53.4%–72.2%) and 94.2% (95% CI = 84.6%–98%) respectively. The positive likelihood ratio (LR+) was 3.39 (95% CI = 2.26–5.11) for a negative likelihood ratio of 0.12 (95% CI = 0.04–0.36).

Conclusions

The blinq device has good sensitivity, but insufficient specificity to be used alone in the first line of screening. Whereas other devices on the market detect risk factors that may lead to amblyopia, the blinq pediatric vision scanner detects poor foveolar fixation and strabismus, giving it a potential advantage in sensitivity to directly detect strabismus, including microstrabismus. The blinq does not detect refractive abnormalities, however, and will therefore need to be improved in the future to be used alone in pediatric vision screening.

Translational Relevance

The blinq device detects visual axis alignment abnormalities with potential impact in the early detection of strabismus and subsequent associated amblyopia.

Visual acuity percentile curves in a Spanish paediatric population

PURPOSE

The main objective of this study is to obtain percentile curves of monocular and binocular visual acuity on a decimal scale in a Spanish population aged between 3 and 12 years old.

MATERIALS AND METHOD

Descriptive, observational and transversal study which included children between 3 and 12 years old without any known eye and/or systemic diseases. The selection of the sample was made by means of a convenience sampling method carried out in three schools and a hospital of the Community of Madrid. Far monocular and binocular visual acuity was measured using the Bueno Matilla vision unit on a decimal scale, both for monocular and binocular tests. The test used was the symmetrical letters test included with this unit. A descriptive statistic was performed and the visual acuity percentile values obtained were 5, 10, 25, 50, 75, 90 and 95.

RESULTS

The visual acuity of 1300 children was evaluated and analysed. In all the percentile curves obtained, an increase in age-related visual acuity has been observed, reaching a value close to the unit for the 50th percentile, around five years and three months of age, under monocular conditions and somewhat earlier in binocular conditions.

CONCLUSION

Although the type of sampling performed does not allow a generalization to the entire population, these percentile curves may help the paediatric professional to decide the referral of the relevant child to the eyecare professional, so that certain conditions, like amblyopia or the early stages of school myopia may be early detected.

Higher Visual Function Deficits in Children With Cerebral Visual Impairment and Good Visual Acuity

In clinical practice Cerebral Visual Impairment (CVI) is typically diagnosed by observation of abnormal visually guided behaviors which indicate higher visual function deficits (HVFDs) suggesting abnormal brain development or brain damage in a child with a suitable clinical history. HVFDs can occur even in the presence of good visual acuity and may remain undiagnosed because the good visual acuity does not prompt further investigation. This leads to a lack of understanding of the child's visual perceptual difficulties. In a prospective study, we determined the spectrum of HVFDs in a group of children with history suggestive of brain damage or disruption of brain development and an independent diagnosis of CVI in comparison with typically developing children with a structured 51 question inventory, the Higher Visual Function Question Inventory (HVFQI-51) adapted from the Cerebral Vision Impairment Inventory, CVI-I. Here, we show that the HVFQI-51 can detect a range of HVFDs in children with CVI with good visual acuity and clearly distinguishes these children from typically developing children. HVFDs in our study group could mostly be attributed to dorsal stream visual processing dysfunction though the spectrum varied between children. We report on the inclusion of the "not applicable" response option in analysis providing a picture of HVFDs more in tune with the overall disability of each child. We also propose a subset of 11 questions (Top-11) which discriminate between children with CVI vs. behaviors seen in typical children: this provides both a potential screening tool for initial assessment of HVFDs and a measure of CVI-related impairment, and needs further validation in a secondary independent sample.

The dynamic optotype (Dyop): a novel visual acuity test for use in children

PURPOSE

To evaluate the "dynamic optotype" (Dyop), a simple visual acuity test based on a dynamic target that requires minimal knowledge of symbols and letters.

METHODS

A total of 160 consecutive, systemically healthy children, 4-17 years of age were prospectively recruited from the Pediatric Ophthalmology Unit of Meir Medical Center. Children were tested with the Dyop visual acuity test and the Early Treatment Diabetic Retinopathy Study (ETDRS) Lea numbers chart. The results of both tests were compared. The eye with the poorest acuity was tested with the new Dyop eye chart and the Lea numbers chart. The order of the testing was reversed between children. The logMAR visual acuity scores for each eye chart were compared.

RESULTS

We found a strong linear correlation (r = 0.88) between visual acuity measures. The mean difference in visual acuity was -0.01 (95% CI, -0.02 to 0.01). The 95% limits of agreement were ±1.2 lines. The logMAR equivalent mean difference was about less than 1 letter. The Dyop test underestimated visual acuity relative to the Lea numbers chart.

CONCLUSIONS

The results of this study support the Dyop eye chart as a valid measure of visual acuity in children 4-17 years of age, with visual acuity ranging from 20/16 to 20/200.

Technologies supporting vision screening: a protocol for a scoping review

INTRODUCTION

Vision problems affect academic performance, social and mental health. Most traditional vision screening methods rely on human expert assessments based on a set of vision tests. As technology advances, new instruments and computerised tools are available for complementing vision screening. The scoping review based on this protocol aims to investigate current technologies for vision screening, what vision tests can be complemented by technologies, and how these can support vision screening by providing measurements.

METHODS AND ANALYSIS

The planned review will utilise the PRISMA extension for Scoping Reviews (PRISMA-ScR) tool. Electronic search will be performed in databases, including Web of Science, MEDLINE (Ovid), Scopus, Engineering Village, Cochrane and Embase. We will perform a systematic search in selected reference databases without the limitation on publications dates, or country of studies. Reference management software, like EndNote and DistillerSR, will be used to remove duplicate entries. Two authors will independently analyse the studies for inclusion eligibility. Conflicts will be resolved by discussion. We will extract the types of technologies, types of vision tests they complement and the measurements for the included studies. Overall findings will be synthesised by thematic analysis and mapping to the logic model.

ETHICS AND DISSEMINATION

Ethical approval is not required for this review, as it will only summarise existing published data. We will publish the findings in an open access, peer-reviewed journal. We expect that the review results will be useful for vision screening experts, developers, researchers, and policymakers.

Establishing Prediction Intervals for the SpeedWheel Acuity Test in Adults and Children

BACKGROUND

The SpeedWheel (SW) test is an objective test of visual acuity (VA) using suppression of the optokinetic nystagmus (OKN). Here, we established prediction intervals of the SW measures compared to Snellen acuity in adults and children.

SUBJECTS AND METHODS

In this prospective, single center study, subjects aged at least 4 years underwent testing of VA with SW, Landolt-C, and Tumbling-E symbols (Freiburg acuity test: FrACT-C, FrACT-E). Prediction intervals were established for SW compared to FrACT-C or -E and for FrACT-E compared to FrACT-C. Mixed linear effect models were applied for statistical analysis.

RESULTS

From 241 subjects, 471 eyes were included: median age 36 years, range 4 - 88 years, 43.6% male, 56.4% female. Eyes included were either healthy or had various underlying ophthalmic conditions. Prediction intervals for SW to estimate FrACT-C or -E acuity showed a similar range compared to the prediction interval of FrACT-C for the estimation of FrACT-E acuity. For each acuity step, there was no influence of age. Up to an SW acuity of 0.7 logMAR, 80% of the subjects had a FrACT-C acuity that was at most 1.6 logMAR lines below, and for an SW acuity of 1.0 logMAR, FrACT-C acuity was not worse than 4 logMAR lines. Prediction intervals for eyes with refractive error, cataract, visual field loss and retinal disease did not differ significantly from healthy eyes in contrast to eyes with amblyopia or multiple ophthalmic disorders. SW correlated well to FrACT tests and results of a previous study fell within our prediction estimates.

CONCLUSION

Our prediction intervals for SW acuity may be used to estimate Snellen acuity (FrACT-C and -E) in the clinic in adults and children unable to cooperate in other acuity testing.

Diagnostic accuracy of the Parr vision test, single crowded Lea symbols and Spot vision screener for vision screening of preschool children aged 4-5 years in Aotearoa/New Zealand

PURPOSE

Preschool children in New Zealand undergo vision screening to detect amblyopia at 4-5 years of age. The current test, the Parr vision test, does not meet international visual acuity chart guidelines and has not been validated against other commonly used paediatric vision tests. New Zealand vision screening protocols are also not targeted for detecting other eye conditions such as uncorrected refractive error, which may affect school performance. We compared the Parr vision test with the single crowded Lea symbols and the Spot vision screener for detecting ocular pathology, refractive error and amblyopic risk factors in preschool children.

METHODS

A cross-sectional diagnostic accuracy study recruited children aged 4-5 years via convenience sampling from the University of Auckland Optometry Clinic and through primary schools in Auckland, New Zealand. Participants received vision screening with the three different instruments administered by a lay screener. Comprehensive eye examinations were completed by a paediatric optometrist to determine the presence of vision disorders.

RESULTS

Of 197 children who received a comprehensive eye examination, 14 (7.1%) had amblyopic risk factors and 43 (21.8%) had significant refractive error (15.7% with astigmatism, 9.1% with hyperopia). The sensitivity for detecting any ocular condition did not differ significantly between the tests (50.0% for Parr, 43.5% for Lea, 42.5% for Spot). Specificity was significantly lower for the Parr vision test (80.8%) than for the Lea symbols (93.4%) and Spot vision screener (98.0%). Adding the Spot vision screener to measurements of visual acuity significantly improved sensitivity in detecting any ocular condition with the Parr vision test (67.5% for Parr/Spot vs 50% for Parr alone), but not with the Lea symbols (52.5% for Lea/Spot vs 43.5% for Lea alone).

CONCLUSION

The sensitivity of the Parr vision test for detecting ocular conditions in preschool children does not vary significantly from that achieved by the Lea symbols or the Spot vision screener. However, current New Zealand vision screening protocols could be improved by expanding the target conditions to include significant refractive error and incorporating the use of the Spot vision screener to increase the accuracy with which children with refractive error are identified. Future research should include longitudinal studies to determine the effect of preschool vision screening on later ocular and academic outcomes.

Psychophysical Validation of a Novel Active Learning Approach for Measuring the Visual Acuity Behavioral Function

Purpose

To evaluate the performance of the quantitative visual acuity (qVA) method in measuring the visual acuity (VA) behavioral function.

Methods

We evaluated qVA performance in terms of the accuracy, precision, and efficiency of the estimated VA threshold and range in Monte Carlo simulations and a psychophysical experiment. We also compared the estimated VA threshold from the qVA method with that from the Electronic Early Treatment Diabetic Retinopathy Study (E-ETDRS) and Freiburg Visual Acuity Text (FrACT) methods. Four repeated measures with all three methods were conducted in four Bangerter foil conditions in 14 eyes.

Results

In both simulations and psychophysical experiment, the qVA method quantified the full acuity behavioral function with two psychometric parameters (VA threshold and VA range) with virtually no bias and with high precision and efficiency. There was a significant correlation between qVA estimates of VA threshold and range in the psychophysical experiment. In addition, qVA threshold estimates were highly correlated with those from the E-ETDRS and FrACT methods.

Conclusions

The qVA method can provide an accurate, precise, and efficient assessment of the full acuity behavioral function with both VA threshold and range.

Translational Relevance

The qVA method can accurately, precisely, and efficiently assess the full VA behavioral function. Further research will evaluate the potential value of these rich measures for both clinical research and patient care.

Myopia

Myopia, also known as short-sightedness or near-sightedness, is a very common condition that typically starts in childhood. Severe forms of myopia (pathologic myopia) are associated with a risk of other associated ophthalmic problems. This disorder affects all populations and is reaching epidemic proportions in East Asia, although there are differences in prevalence between countries. Myopia is caused by both environmental and genetic risk factors. A range of myopia management and control strategies are available that can treat this condition, but it is clear that understanding the factors involved in delaying myopia onset and slowing its progression will be key to reducing the rapid rise in its global prevalence. To achieve this goal, improved data collection using wearable technology, in combination with collection and assessment of data on demographic, genetic and environmental risk factors and with artificial intelligence are needed. Improved public health strategies focusing on early detection or prevention combined with additional effective therapeutic interventions to limit myopia progression are also needed.

Evidence-Based Clinical Practice Guideline: Comprehensive Pediatric Eye and Vision Examination

Republished with written permission granted from the American Optometric Association, October 2, 2020.

Reduced visual acuity in children from 5 to 6 years old, with LEA chart

PURPOSE

To assess visual acuity in 5-year-old children with LEA chart and to estimate the frequency of reduced visual acuity in this age.

METHOD

Study aimed at children attending the last year of preschool education in Public Kindergartens and Private Social Solidarity Institutions (IPSS) under the influence Regional Health Administration of the Médio Tejo, in Portugal. The 15-line LEA charts at 3 m were used and the presentation visual acuity was measured monocularly starting with the right eye. The ETDRS-fast methodology was used.

RESULTS

A total of 3072 children participated, being 51% male and 54% from rural area. A rate of 13.7% children with a reduced level of visual acuity was found, that is, visual acuity worse or equal to 0.2 logMAR in at least one eye, or an interocular difference greater than two lines.

CONCLUSION

This research shows that reduced VA frequency rate in children between 5 and 6 years old is high. The literature presents amblyopia (refractive and/or strabismic) and uncorrected refractive errors without amblyopia as the main cause of reduced VA in childhood, and these anomalies negatively affect child development, especially at the educational level. Reduced VA interferes with performance on a number of key tasks in the learning process. Thus, it is important to preserve the running program to identify these deficits and lead to their correction before the beginning of the school stage.

Detection vision development in infants and toddlers with congenital vision disorders and profound-severe visual impairment

AIM

To investigate detection vision development in infants and toddlers with congenital disorders of the peripheral visual system (CDPVS) and severe to profound visual impairment (SVI/PVI).

METHOD

This was a longitudinal observational investigation of a cohort of infants with CDPVS (entry age 8-16mo) followed up 12 months later. Detection vision (Near Detection Scale [NDS]) and resolution acuity (Keeler Acuity Cards [KAC]) were assessed at each time point. Relationships between detection vision, resolution acuity, and age were investigated.

RESULTS

The study cohort comprised 80 children (39 females, 41 males), mean age 13 months (Time 1) and 26 months (Time 2); 22 (27.5%) with PVI (light perception at best) and 58 (72.5%) with SVI (basic 'form' vision) at Time 1. All children achieved a measure with the NDS, however only 35 per cent and 56 per cent at Time 1 and Time 2 respectively did so on KAC. Those with PVI at Time 1 showed no further improvement at Time 2, but 87 per cent of children with SVI showed improvement in vision. The median change in NDS score was 1.0 (range 1-7, SD 1.68).

INTERPRETATION

Vision development continues after 12 months of age in many toddlers if they have basic 'form' vision. A measure of detection vision is feasible in very young children when resolution acuity measurement is not achievable.

WHAT THIS PAPER ADDS

The Near Detection Scale (NDS) can measure low levels of vision when acuity is not otherwise measurable. Vision can improve in toddlers with severe visual impairment who have some 'form' vision. Infants with light perception at best by 12 months are unlikely to show improvement in vision. There is a moderate negative relationship between the NDS and resolution acuity results.

Normative data for the redesigned Kay Pictures visual acuity test

The Kay Picture Test of visual acuity is used extensively in the diagnosis and management of children. The test has been redesigned and validated to meet the international visual acuity chart guidelines, necessitating the collection of new normative data. The data presented here demonstrates that the visual acuities of children <60 months of age with no visual deficiency improve with age and show no significant intraocular difference. This is the first report of normative data in young children for the redesigned Kay Pictures Test (singles format).

Differential visual acuity - A new approach to measuring visual acuity

BACKGROUND

A novel type of acuity measurement, which we refer to as 'differential acuity', requires the observer to identify one unique target among three others which are identical. This is a proof of concept study aimed to determine if differential acuity is equivalent to standard measures of recognition acuity.

METHODS

To create a range of visual acuity, vision was optically blurred in sixteen adults with normal visual acuity. Visual acuity was then measured with the differential acuity targets in both crowded and uncrowded format, and compared with standard ETDRS acuity or with singly presented letters and uncrowded letters were analysed separately.

RESULTS

The visual acuity results for crowded and uncrowded letters were analysed separately. Repeated measures analysis of variance showed that when a crowded Sloan C had to be differentiated from three crowded Os (CvsO), the results were not significantly different from ETDRS acuity or from naming one of four letters presented centrally (Name4) (p<0.05). Similar results were found for uncrowded letters - the C versus O and Name4 gave similar visual acuity. The 95% limits of agreement between the naming and C versus O differential acuity measures were between 0.17 and 0.27 logMAR.

CONCLUSION

From this proof of concept study we conclude that differential acuity gives similar results to the ETDRS chart in adults. We infer that the comparable but cognitively simpler differential visual acuity task could be applied in clinical settings for young children or patients with developmental delay who cannot respond by naming or matching.

Optic Pathway Glioma in Type 1 Neurofibromatosis: Review of Its Pathogenesis, Diagnostic Assessment, and Treatment Recommendations

Type 1 neurofibromatosis (NF1) is a dominantly inherited condition predisposing to tumor development. Optic pathway glioma (OPG) is the most frequent central nervous system tumor in children with NF1, affecting approximately 15-20% of patients. The lack of well-established prognostic markers and the wide clinical variability with respect to tumor progression and visual outcome make the clinical management of these tumors challenging, with significant differences among distinct centers. We reviewed published articles on OPG diagnostic protocol, follow-up and treatment in NF1. Cohorts of NF1 children with OPG reported in the literature and patients prospectively collected in our center were analyzed with regard to clinical data, tumor anatomical site, diagnostic workflow, treatment and outcome. In addition, we discussed the recent findings on the pathophysiology of OPG development in NF1. This review provides a comprehensive overview about the clinical management of NF1-associated OPG, focusing on the most recent advances from preclinical studies with genetically engineered models and the ongoing clinical trials.

Diagnostic accuracy and agreement between visual acuity charts for detecting significant refractive errors in preschoolers

BACKGROUND

Preschool vision screenings are considered to be cost-effective methods to identify children with vision disorders. The children of this age group are poor at communicating their symptoms and hence screening is mandated. This study is aimed at estimating the diagnostic accuracy and agreement of Lea, HOTV and E visual acuity charts for detecting significant refractive errors.

METHODS

A cross-sectional study was conducted, in which monocular unaided vision assessment of each study participant was performed with Lea, HOTV and E charts. Stereo acuity was measured with the Randot Preschool Test and a comprehensive eye examination including dilatation was performed. Significant refractive error was defined as hyperopia > 3.25 D, myopia > 2.00 D, astigmatism > 1.50 D, anisometropia if interocular difference > 1.00 D for hyperopia, > 3.00 D for myopia or > 1.50 D for astigmatism. Sensitivity, specificity, positive and negative predictive values were estimated. Bland-Altmann plots were generated to help identify the level of agreement between the vision charts.

RESULTS

A total of 256 eyes were analysed. Lea, HOTV and E had sensitivities of 87.8 per cent, 90.2 per cent and 90.2 per cent, respectively. Specificity and positive predictive values were better for HOTV (77.3 per cent, 65.5 per cent) and Lea (75 per cent, 62.6 per cent), compared to E chart (69.8 per cent, 58.7 per cent). Negative predictive values for Lea, HOTV and E charts were 92.8 per cent, 93.8 per cent and 93.8 per cent, respectively. Bland-Altmann analysis showed good agreement between Lea and HOTV, Lea and E, and HOTV and E visual acuity charts. The acuity difference was least between Lea and HOTV charts (0.1 logMAR). Eighty-five (33.2 per cent) eyes had significant refractive errors. Eighty (94.1 per cent) eyes were astigmatic.

CONCLUSION

The diagnostic accuracy of the visual acuity charts was high for the identification of significant refractive errors in preschool children. There was very good agreement between the visual acuity charts.

Parents' performance using the AAPOS Vision Screening App to test visual acuity in Malaysian preschoolers

PURPOSE

To evaluate parents' performance in using the American Association for Pediatric Ophthalmology and Strabismus (AAPOS) Vision Screening App (application) as a vision screening tool among preschool children and to evaluate the reliability of this app.

METHODS

A total of 195 5- and 6-year-old preschoolers were recruited from children attending Hospital Selayang, Selangor, Malaysia, to test the app. Uncooperative children and those with visual acuity of >logMAR 0.6 were excluded. Results from parents and the screening doctor using the app (Lea symbols) to test visual acuity were compared to each other and to gold standard vision testing by an optometrist using the Lea symbols chart.

RESULTS

Children 5 years of age represented 46.7% of the study population. The mean age of parents was 37.27 ± 7.68 years. Bland-Altman scatterplot agreement between assessors mainly was within the 95% confidence interval for bilateral eyes screening. Parents obtained a sensitivity of 86.6% (right vision) and 79.5% (left vision) and specificity of 78.9% (right vision) and 71.8% (left vision). Parents took a mean of 191.2 ± 70.82 seconds for bilateral screening. The intraclass correlation coefficient between optometrist and parents in bilateral eyes screening was good (P < 0.001). Cronbach's α for all three assessors was >0.7, indicating high internal reliability of the app. Most parents (178/195 [91.3%]) strongly agreed on the app's acceptability and ease of use.

CONCLUSIONS

The AAPOS Vision Screening App used by parents is a promising tool for visual acuity screening among Malaysian preschool children and a reliable app for vision screening.

Objective measurement of visual acuity by optokinetic nystagmus suppression in children and adult patients

PURPOSE

To investigate the correlation between subjective and objective visual acuity as elicited with a new computerized optokinetic nystagmus (OKN) suppression test ("SpeedWheel") in adults and school-aged children.

METHODS

Fifteen children (6-12 years) and 27 adults with refractive errors, amblyopia, cataract, age-related macular degeneration, and thyroid-associated orbitopathy underwent testing of subjective visual acuity with E- and Landolt-C symbols (Freiburg Acuity and Contrast Test [FrACT]) and visual acuity as estimated with the SpeedWheel on an LCD screen.

STATISTICAL ANALYSIS

linear regression, Spearman correlation, and Bland-Altman plots.

RESULTS

Mean difference against the mean was -0.01 when SpeedWheel was compared to Landolt C, but -0.15 when compared to E-symbols. Overall, SpeedWheel correlated very strongly to FrACT ("E": r = 0.85; P < 0.001; Landolt-C: r = 0.81; P < 0.001). This also held true in children ("E": r = 0.74; P < 0.003; Landolt-C: r = 0.69; P < 0.005).

CONCLUSIONS

SpeedWheel enables estimation of visual acuity in a variety of conditions in both adults and school-aged children.

Designing and Testing of the Software Module Evaluation of Visual Acuity for Information System Eye Center

The aim of this work was to design and implement the application of visual acuity evaluation for the eye center information system. The application was designed for Android Operating System (OS) and was programmed in Android Studio. This work also deals with the implementation of the application, from the design of the user interface, through the creation and configuration of the project in Android Studio to the functionality of individual screens and connection with the back-end.

Undermining a common language: smartphone applications for eye emergencies

Background

Emergency room physicians are frequently called upon to assess eye injuries and vision problems in the absence of specialized ophthalmologic equipment. Technological applications that can be used on mobile devices are only now becoming available.

Objective

To review the literature on the evidence of clinical effectiveness of smartphone applications for visual acuity assessment marketed by two providers (Google Play and iTunes).

Methods

The websites of two mobile technology vendors (iTunes and Google Play) in Canada and Ireland were searched on three separate occasions using the terms “eye”, “ocular”, “ophthalmology”, “optometry”, “vision”, and “visual assessment” to determine what applications were currently available. Four medical databases (Cochrane, Embase, PubMed, Medline) were subsequently searched with the same terms AND mobile OR smart phone for papers in English published in years 2010–2017.

Results

A total of 5,024 Canadian and 2,571 Irish applications were initially identified. After screening, 44 were retained. Twelve relevant articles were identified from the health literature. After screening, only one validation study referred to one of our identified applications, and this one only partially validated the application as being useful for clinical purposes.

Conclusion

Mobile device applications in their current state are not suitable for emergency room ophthalmologic assessment, because systematic validation is lacking.

Eye injuries in children - incidence and outcomes: An observational study at a dedicated children's eye casualty

PURPOSE

Trauma is an important cause of visual loss in children and may affect their quality of life. Prevention and legislation can reduce the incidence of trauma, and appropriate and timely treatment can improve prognosis. We aimed to describe incidence of eye injuries in children and the adherence to national and local management guidelines.

METHODS

Retrospective service evaluation at a tertiary hospital (Moorfields Eye Hospital, London, UK) which operates a dedicated children's eye casualty. The electronic patient administration system and electronic patient record system (Openeyes) were used to identify children who presented with eye injuries between January 2015 and December 2015.

RESULTS

Of 2397 first-time attendances to our children's casualty, 508 were for injuries (estimated incidence 21.1%, 95% confidence interval: 19.5%-22.7%). Mean age at presentation was 7.51 (standard deviation: 7.97) years; boys were more commonly affected than girls (69%). The most common injury was corneal abrasion, followed by blunt and chemical injury; severe injuries such as penetrating trauma were rare. Injuries were sustained mostly during play or sports. Two children sustained permanent loss of vision in the affected eye.

CONCLUSION

Our findings are comparable to other published reports. Adherence to management guidelines is high, but documentation of advice given to families can be improved. Regular training of staff and collaboration with organisations outside the hospital can increase awareness of eye injuries in children.

Vision screening at two years does not reduce the prevalence of reduced vision at four and a half years of age

BACKGROUND

There is currently insufficient evidence to recommend vision screening for children < 36 months of age. This study assessed the effect of comprehensive vision screening, as well as the sensitivity of age-appropriate vision tests, at two years of age on habitual visual acuity at 4.5 years of age.

METHODS

Children born at risk of neonatal hypoglycaemia (n = 477) underwent vision assessment at 54 ± 2 months of age including measurement of monocular and binocular habitual visual acuity, assessment of binocularity and stereopsis. Of these children, 355 (74.4 per cent) had also received vision screening at two years of age (mean age = 24± 1 months), while 122 were not screened.

RESULTS

Eighty (16.8 per cent) children were classified as having reduced vision at 4.5 years of age, but the prevalence of reduced vision did not differ between children who had previously been screened at two years of age and those who had not (15.5 per cent versus 20.5 per cent, p = 0.153). However, children with reduced vision at 4.5 years of age were more likely to have had visual abnormalities requiring referral detected at two years of age (p = 0.02). Visual acuity and mean spherical equivalent autorefraction measurements were also worse (higher values) in two-year-old children who were later classified with reduced habitual visual acuity (p = 0.031 and p = 0.001, respectively). Nevertheless, unaided binocular visual acuity, non-cycloplegic refractive error, and stereopsis at two years all showed poor sensitivity and specificity for predicting visual outcomes at 4.5 years of age.

CONCLUSION

Our findings do not support the adoption of early vision screening in children as current vision tests suitable for use with two-year-old children have poor sensitivity for predicting mild-moderate habitual vision impairment at 4.5 years of age.

Do picture-based charts overestimate visual acuity? Comparison of Kay Pictures, Lea Symbols, HOTV and Keeler logMAR charts with Sloan letters in adults and children

Purpose

Children may be tested with a variety of visual acuity (VA) charts during their ophthalmic care and differences between charts can complicate the interpretation of VA measurements. This study compared VA measurements across four pediatric charts with Sloan letters and identified chart design features that contributed to inter-chart differences in VA.

Methods

VA was determined for right eyes of 25 adults and 17 children (4–9 years of age) using Crowded Kay Pictures, Crowded linear Lea Symbols, Crowded Keeler logMAR, Crowded HOTV and Early Treatment of Diabetic Retinopathy Study (ETDRS) charts in focused and defocused (+1.00 DS optical blur) conditions. In a separate group of 25 adults, we compared the VA from individual Kay Picture optotypes with uncrowded Landolt C VA measurements.

Results

Crowded Kay Pictures generated significantly better VA measurements than all other charts in both adults and children (p < 0.001; 0.15 to 0.30 logMAR). No significant differences were found between other charts in adult participants; children achieved significantly poorer VA measurements on the ETDRS chart compared with pediatric acuity tests. All Kay Pictures optotypes produced better VA (p < 0.001), varying from -0.38 ± 0.13 logMAR (apple) to -0.57 ± 0.10 logMAR (duck), than the reference Landolt C task (mean VA -0.19 ± 0.08 logMAR).

Conclusion

Kay Pictures over-estimated VA in all participants. Variability between Kay Pictures optotypes suggests that shape cues aid in optotype determination. Other pediatric charts offer more comparable VA measures and should be used for children likely to progress to letter charts.

Global prevalence of childhood cataract: a systematic review

Childhood cataract is an avoidable cause of visual disability worldwide and is a priority for VISION 2020: The Right to Sight. There is a paucity of information about the burden of cataract in children and the aim of this review is to assess the global prevalence of childhood cataract. The methodology for the review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We performed a literature search for studies reporting estimates of prevalence or incidence of cataract among children (aged<18 years) at any global location using the Cochrane Library, Medline and Embase up to January 2015. No restrictions were imposed based on language or year of publication. Study quality was assessed using a critical appraisal tool designed for systematic reviews of prevalence. Twenty prevalence and four incidence studies of childhood cataract from five different geographical regions were included. The overall prevalence of childhood cataract and congenital cataract was in the range from 0.32 to 22.9/10000 children (median=1.03) and 0.63 to 9.74/10000 (median=1.71), respectively. The incidence ranged from 1.8 to 3.6/10000 per year. The prevalence of childhood cataract in low-income economies was found to be 0.42 to 2.05 compared with 0.63 to 13.6/10000 in high-income economies. There was no difference in the prevalence based on laterality or gender. This review highlights substantial gaps in the epidemiological knowledge of childhood cataract worldwide, particularly from low and lower middle-income economies. More studies are needed using standard definitions and case ascertainment methods with large enough sample sizes.