Perimetry in young and neurologically impaired children: the Behavioral Visual Field (BEFIE) Screening Test revisited

Neurological and Visual Outcomes in Infants and Toddlers Following Therapeutic Hypothermia for Neonatal Hypoxic-Ischemic Encephalopathy

BACKGROUND

The majority of studies have investigated neurodevelopmental outcomes, whereas visual impairment is less explored in children with a history of neonatal (hypoxic-ischemic) encephalopathy. Our aim was to perform a detailed neurological and visual assessment and also to investigate the presence of cerebral visual impairment in infants and toddlers with neonatal encephalopathy.

METHODS

Thirty participants with a history of neonatal encephalopathy, who had been hospitalized for therapeutic hypothermia, underwent a detailed neurological examination at age five to 36 months. Age-matched, 30 healthy children were also enrolled as a control group. All children in the study and control groups received neurological and a comprehensive ophthalmologic examination, including visual field and visual acuity. Presence of cerebral visual impairment was also evaluated clinically.

RESULTS

Rates of cerebral palsy, severe motor impairment, cognitive impairment, epilepsy, and cerebral visual impairment were found to be 20%, 10%, 15.3%, 10%, and 20%, respectively. When compared with healthy controls, oculomotor functions, pupillary light response, refractive parameters, anterior/posterior segment examinations, ocular visual impairment rates, and last, visual acuities were found similar. However, we found a statistically significant increase in visual field defects in our study group.

CONCLUSIONS

It could be better to perform a comprehensive ophthalmologic examination including visual field, visual acuity, and oculomotor functions by a pediatric ophthalmologist to accurately diagnose neurovisual deficits in infants following therapeutic hypothermia. Early identification and rehabilitation of the visual deficits might improve the neurodevelopment in these children.

Diagnostic accuracy of retinal optical coherence tomography in children with a newly diagnosed brain tumour

PURPOSE

To estimate the diagnostic accuracy of circumpapillary retinal nerve fibre layer (RNFL) thickness and macular ganglion cell layer-inner plexiform layer (GCL-IPL) thickness measurements to discriminate an abnormal visual function (i.e. abnormal age-based visual acuity and/or visual field defect) in children with a newly diagnosed brain tumour.

METHODS

This cross-sectional analysis of a prospective longitudinal nationwide cohort study was conducted at four hospitals in the Netherlands, including the national referral centre for paediatric oncology. Patients aged 0-18 years with a newly diagnosed brain tumour and reliable visual acuity and/or visual field examination and optical coherence tomography were included. Diagnostic accuracy was evaluated with sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV).

RESULTS

Of 115 patients included in the study (67 [58.3%] male; median age 10.6 years [range, 0.2-17.8 years]), reliable RNFL thickness and GCL-IPL thickness measurements were available in 92 patients (80.0%) and 84 patients (73.0%), respectively. The sensitivity for detecting an abnormal visual function was 74.5% for average RNFL thickness and 41.7% for average GCL-IPL thickness at a specificity of 44.5% and 82.9%, respectively. The PPV and NPV were 33.0% and 82.6% for the average RNFL thickness and 57.1% and 82.2% for the average GCL-IPL thickness.

CONCLUSION

An abnormal visual function was discriminated correctly by using the average RNFL thickness in seven out of ten patients and by using the average GCL-IPL thickness in four out of ten patients. The relatively high NPVs signified that patients with normal average RNFL thickness and average GCL-IPL thickness measurements had a relative high certainty of a normal visual function.

Impact of Bevacizumab on Visual Function, Tumor Size, and Toxicity in Pediatric Progressive Optic Pathway Glioma: A Retrospective Nationwide Multicentre Study

BACKGROUNDS

Bevacizumab (BVZ) is used as a subsequent line of treatment for pediatric optic pathway glioma (OPG) in the case of progression. Data on the treatment effect concerning tumor progression and visual function are scarce and nationwide studies are lacking.

METHODS

We performed a retrospective, nationwide, multicentre cohort study including all pediatric patients with OPG treated with BVZ in the Netherlands (2009-2021). Progression-free survival, change in visual acuity and visual field, MRI-based radiologic response, and toxicity were evaluated.

RESULTS

In total, 33 pediatric patients with OPG were treated with BVZ (median 12 months). Visual acuity improved in 20.5%, remained stable in 74.4%, and decreased in 5.1% of 39 of all analysed eyes. The monocular visual field improved in 73.1%, remained stable in 15.4%, and decreased in 7.7% of 25 analysed eyes. Radiologic response at the end of therapy showed a partial response in 7 patients (21.9%), minor response in 7 (21.9%), stable disease in 15 (46.9%), and progressive disease in 3 (9.3%). Progression-free survival at 18 and 36 months after the start of BVZ reduced from 70.9% to 38.0%. Toxicity (≥grade 3 CTCAE) during treatment was observed in five patients (15.2%).

CONCLUSION

Treatment of BVZ in pediatric patients with OPG revealed stabilisation in the majority of patients, but was followed by progression at a later time point in more than 60% of patients. This profile seems relatively acceptable given the benefits of visual field improvement in more than 70% of analysed eyes and visual acuity improvement in more than 20% of eyes at the cessation of BVZ.

Development and validation of the Visual Function Battery for Children with Special Needs

AIM

To develop and validate the Visual Function Battery for Children with Special Needs (VFB-CSN).

METHOD

This was a scale development and validation study with (1) construct and item generation and (2) evaluations of interrater reliability, acceptability, and content, ecological, and convergent validities.

RESULTS

Children with special needs were recruited for the reliability (n = 32) and validity (n = 95) investigations. The construct and items were generated based on literature review and an expert panel. We constructed eight categories, namely visual reflex, ocular muscle balance, visual acuity, oculomotor, visual field, contrast sensitivity, colour/form vision, and visual attention. Both functional assessment and standardized tests were adopted. The reliabilities were high for the whole VFB-CSN (intraclass correlation coefficient [ICC] = 0.90, 95% confidence interval [CI] = 0.80-0.90) and good for the oculomotor, contrast sensitivity, and colour/form vision (ICC = 0.80-0.86, 95% CI = 0.50-0.93). Correlations between the VFB-CSN and the Functional Vision Questionnaire were strong and acceptable for the contrast sensitivity, acuity, and colour/form vision (r = 0.79, r = 0.69, r = 0.69, r = 0.70 respectively). The correlation between the VFB-CSN and standardized visual acuity test was acceptable (r = -0.72).

INTERPRETATION

The VFB-CSN is a reliable and valid multifaceted battery for children with special needs. Acceptable psychometric properties were also found for the acuity and contrast sensitivity.

Ophthalmological Findings in Youths With a Newly Diagnosed Brain Tumor

Importance

Visual impairment is an irreversible adverse effect in individuals who experienced a childhood brain tumor. Ophthalmological evaluation at diagnosis enables early detection of vision loss, decision-making about treatment, and when applicable, the timely use of visual interventions. However, awareness of visual impairment in clinical practice is suboptimal, and adherence to ophthalmological evaluation needs to be improved.

Objective

To assess the prevalence and types of abnormal ophthalmological findings in youths with a newly diagnosed brain tumor.

Design, Setting, and Participants

In this nationwide, prospective cohort study, youths aged 0 to 18 years with a newly diagnosed brain tumor between May 15, 2019, and August 11, 2021, were consecutively enrolled in 4 hospitals in the Netherlands, including the dedicated tertiary referral center for pediatric oncology care.

Exposures

A standardized and comprehensive ophthalmological examination, including orthoptic evaluation, visual acuity testing, visual field examination, and ophthalmoscopy, was performed within 4 weeks from brain tumor diagnosis.

Main Outcomes and Measures

The main outcomes were prevalence and types of visual symptoms and abnormal ophthalmological findings at brain tumor diagnosis.

Results

Of 170 youths included in the study (96 [56.5%] male; median age, 8.3 years [range, 0.2-17.8 years]), 82 (48.2%) had infratentorial tumors; 53 (31.2%), supratentorial midline tumors; and 35 (20.6%), cerebral hemisphere tumors. A total of 161 patients (94.7%) underwent orthoptic evaluation (67 [41.6%] preoperatively; 94 [58.4%] postoperatively); 152 (89.4%), visual acuity testing (63 [41.4%] preoperatively; 89 [58.6%] postoperatively); 121 (71.2%), visual field examination (49 [40.4%] preoperatively; 72 [59.6%] postoperatively); and 164 (96.5%), ophthalmoscopy (82 [50.0%] preoperatively; 82 [50.0%] postoperatively). Overall, 101 youths (59.4%) presented with visual symptoms at diagnosis. Abnormal findings were found in 134 patients (78.8%) during ophthalmological examination. The most common abnormal findings were papilledema in 86 of 164 patients (52.4%) who underwent ophthalmoscopy, gaze deficits in 54 of 161 (33.5%) who underwent orthoptic evaluation, visual field defects in 32 of 114 (28.1%) with reliable visual field examination, nystagmus in 40 (24.8%) and strabismus in 32 (19.9%) of 161 who underwent orthoptic evaluation, and decreased visual acuity in 13 of 152 (8.6%) with reliable visual acuity testing. Forty-five of 69 youths (65.2%) without visual symptoms at diagnosis had ophthalmological abnormalities on examination.

Conclusions and Relevance

The results of this study suggest that there is a high prevalence of abnormal ophthalmological findings in youths at brain tumor diagnosis regardless of the presence of visual symptoms. These findings support the need of standardized ophthalmological examination and the awareness of ophthalmologists and referring oncologists, neurologists, and neurosurgeons for ophthalmological abnormalities in this patient group.

Comparison of unifocal, flicker, and multifocal pupil perimetry methods in healthy adults

To this day, the most popular method of choice for testing visual field defects (VFDs) is subjective standard automated perimetry. However, a need has arisen for an objective, and less time-consuming method. Pupil perimetry (PP), which uses pupil responses to onsets of bright stimuli as indications of visual sensitivity, fulfills these requirements. It is currently unclear which PP method most accurately detects VFDs. Hence, the purpose of this study is to compare three PP methods for measuring pupil responsiveness.

Unifocal (UPP), flicker (FPP), and multifocal PP (MPP) were compared by monocularly testing the inner 60 degrees of vision at 44 wedge-shaped locations. The visual field (VF) sensitivity of 18 healthy adult participants (mean age and SD 23.7 ± 3.0 years) was assessed, each under three different artificially simulated scotomas for approximately 4.5 minutes each (i.e. stimulus was not or only partially present) conditions: quadrantanopia, a 20-, and 10-degree diameter scotoma.

Stimuli that were fully present on the screen evoked strongest, partially present stimuli evoked weaker, and absent stimuli evoked the weakest pupil responses in all methods. However, the pupil responses in FPP showed stronger discriminative power for present versus absent trials (median d-prime = 6.26 ± 2.49, area under the curve [AUC] = 1.0 ± 0) and MPP performed better for fully present versus partially present trials (median d-prime = 1.19 ± 0.62, AUC = 0.80 ± 0.11).

We conducted the first in-depth comparison of three PP methods. Gaze-contingent FPP had best discriminative power for large (absolute) scotomas, whereas MPP performed slightly better with small (relative) scotomas.

Ophthalmological Evaluation in Children Presenting With a Primary Brain Tumor

BACKGROUND

Children with a brain tumor are prone to develop visual impairment, which to date is often underestimated and unrecognized. Our aim was to assess the prevalence of ophthalmological evaluation and abnormal ophthalmological findings, and investigate whether demographic and tumor-related characteristics are associated with abnormal ophthalmological findings in children presenting with a primary brain tumor.

METHODS

Medical records of all 90 children diagnosed with a primary brain tumor between June 2018 and May 2019 and treated at the Princess Máxima Center for Pediatric Oncology, a tertiary referral center in the Netherlands, were retrospectively reviewed. Univariate regression analysis was used to investigate associations between demographic, tumor-related and clinical characteristics, and abnormal ophthalmological findings.

RESULTS

Sixty children (34 male [56.7%]; median [range] age, 9.3 [0-16.9] years) underwent ophthalmological evaluation within 6 weeks before or after diagnosis, 11 children (5 male [45.5%]; median [range] age, 5.7 [0.1-17.2] years) were seen more than 6 weeks before or after diagnosis, and 19 children (7 male [36.8%]; median [range] age, 7.2 [1.9-16.6] years) did not receive ophthalmological evaluation within at least 6 months from diagnosis. A total of 19 children (21.1%) presented with visual symptoms as first sign leading to the diagnosis of a brain tumor. Children who presented with visual symptoms (odds ratio [OR], 22.52; 95% confidence interval [CI], 4.90-103.60) and/or hydrocephalus (OR, 3.60; 95% CI, 1.38-9.36) at diagnosis were more often seen for ophthalmological evaluation. The most common abnormal ophthalmological findings were eye movement disorders (66.0%), papilledema (44.1%), and visual field defects (58.1%). Eye movement disorders occurred more frequently in patients with an infratentorial tumor (OR, 4.71; 95% CI, 1.03-21.65). The risk of papilledema was associated with older age (OR, 1.19; 95% CI, 1.05-1.34), hydrocephalus (OR, 9.63; 95% CI, 2.68-34.61), and infratentorial (OR, 9.11; 95% CI, 1.77-46.78) and supratentorial (OR, 13.13; 95% CI, 1.92-89.52) tumors.

CONCLUSIONS

In this study, most children with a primary brain tumor underwent ophthalmological evaluation around diagnosis, 21% of the children were not evaluated. The high prevalence of abnormal ophthalmological findings stresses the importance of early standardized ophthalmological evaluation to detect visual impairment and provide timely treatment to potentially prevent permanent visual loss.

The diagnostic accuracy and prognostic value of OCT for the evaluation of the visual function in children with a brain tumour: A systematic review

Purpose

To systematically review the evidence on the diagnostic accuracy and prognostic value of retinal optical coherence tomography (OCT) to detect visual acuity (VA) or visual field (VF) loss in children with a brain tumour.

Methods

PubMed, Embase and Cochrane Library databases were searched from inception to February 2021. We included studies evaluating retinal OCT and standard visual function parameters (VA and or VF) in children with a brain tumour. Two authors independently extracted data from each included study. They also assessed the methodological quality of the studies using the QUADAS-2 or QUIPS tool. The diagnostic accuracy of OCT was evaluated with receiver operating characteristic analysis, sensitivity, specificity, positive predictive value and negative predictive value. The prognostic value of OCT was evaluated with predictive measures (odds ratio).

Results

We included five diagnostic studies, with a total of 186 patients, all diagnosed with optic pathway glioma. No prognostic studies were eligible for inclusion. Included studies evaluated either retinal nerve fiber layer (RNFL) thickness or ganglion cell layer—inner plexiform layer (GCL-IPL) thickness. There was considerable heterogeneity between OCT devices, OCT protocols, visual function parameters and threshold values. Sensitivity and specificity for RNFL thickness measurement ranged from 60.0% to 100.0% and 76.6% to 100%, respectively. For GCL-IPL thickness measurement, area under the curve ranged from 0.91 to 0.98 for different diameters.

Conclusion

The literature regarding the diagnostic accuracy and prognostic value of OCT parameters in children with a brain tumour is scarce. Due to heterogeneity and a considerable risk of bias of included studies, we cannot draw solid conclusions regarding the accuracy of retinal OCT. Future research should investigate the potential of OCT as diagnostic and prognostic tool for the evaluation of the visual function and detection of visual impairment in children with any type of brain tumour.

Pharmacotherapy for Seizures in Tuberous Sclerosis Complex

Epilepsy is one of the main symptoms affecting the lives of individuals with tuberous sclerosis complex (TSC), causing a high rate of morbidity. Individuals with TSC can present with various types of seizures, epilepsies, and epilepsy syndromes that can coexist or appear in relation to age. Focal epilepsy is the most frequent epilepsy type with two developmental and epileptic encephalopathies: infantile spasms syndrome and Lennox-Gastaut syndrome. Active screening and early management of epilepsy is recommended in individuals with TSC to limit its consequences and its impact on quality of life, cognitive outcome and the economic burden of the disease. The progress in the knowledge of the mechanisms underlying epilepsy in TSC has paved the way for new concepts in the management of epilepsy related to TSC. In addition, we are moving from traditional "reactive" and therapeutic choices with current antiseizure medications used after the onset of seizures, to a proactive approach, aimed at predicting and preventing epileptogenesis and the onset of epilepsy with vigabatrin, and to personalized treatments with mechanistic therapies, namely mechanistic/mammalian target of rapamycin inhibitors. Indeed, epilepsy linked to TSC is one of the only epilepsies for which a predictive and preventive approach can delay seizure onset and improve seizure response. However, the efficacy of such interventions on long-term cognitive and psychiatric outcomes is still under investigation.

The Assessment of Visual Fields in Infants Using Saccadic Vector Optokinetic Perimetry (SVOP): A Feasibility Study

Purpose

To examine the feasibility of saccadic vector optokinetic perimetry (SVOP), an automated eye tracking perimeter, as a tool for visual field (VF) assessment in infants.

Methods

Thirteen healthy infants aged between 3.5 and 12.0 months were tested binocularly using an adapted SVOP protocol. SVOP uses eye tracking technology to measure gaze responses to stimuli presented on a computer screen. Modifications of SVOP for testing infants included adjusting the fixation target to display a short animation, increasing the stimulus size to equivalent to Goldmann V, and introducing a tiered test pattern strategy. Binocular, single-quadrant confrontation VF testing and Keeler preferential looking cards visual acuity testing was also performed.

Results

Using multiple test attempts when required, all but the youngest infant (12 of 13 [92.3%]) successfully completed a 4-point screening test. Seven infants (53.8%) successfully completed the 12-point test, four (30.8%) successfully completed the 20-point test, and three (23.1%) successfully completed the 40-point test. The effect of multiple test attempts and the complexity of the test pattern (number of test points) on performance was investigated, including test completion rate, percentage of correctly seen stimuli, and average time per tested stimulus.

Conclusions

The modified SVOP test strategy allowed successful assessment of binocular VFs in healthy infants. Future data collection from larger cohorts of infants is needed to derive normative limits of detection and assess accuracy in detecting and monitoring infant VF abnormalities.

Translational Relevance

Eye tracking perimetry may provide a useful method of automated VF assessment in infants.

Visual functions in children with craniopharyngioma at diagnosis: A systematic review

Childhood craniopharyngioma is a rare and slow growing brain tumour, often located in the sellar and suprasellar region. It commonly manifests with visual impairment, increased intracranial pressure and hypothalamic and/or pituitary deficiencies. Visual impairment in childhood adversely affects a child’s daily functioning and quality of life. We systematically reviewed the literature to provide an extensive overview of the visual function in children with craniopharyngioma at diagnosis in order to estimate the diversity, magnitude and relevance of the problem of visual impairment. Of the 543 potentially relevant articles, 84 studies met our inclusion criteria. Visual impairment at diagnosis was reported in 1041 of 2071 children (50.3%), decreased visual acuity was reported in 546 of 1321 children (41.3%) and visual field defects were reported in 426 of 1111 children (38.3%). Other ophthalmological findings described were fundoscopic (32.5%) and orthoptic abnormalities (12.5%). Variations in ophthalmological testing methods and ophthalmological definitions precluded a meta-analysis. The results of this review confirm the importance of ophthalmological examination in children with craniopharyngioma at diagnosis in order to detect visual impairment and provide adequate support. Future studies should focus on long-term visual follow-up of childhood craniopharyngioma in response to different treatment strategies to provide insight in risks and ways to prevent further loss of vision.

Lessons Learned from 23 Years of Experience in Testing Visual Fields of Neurologically Impaired Children

We sought to investigate the reliability of standard conventional perimetry (SCP) in neurologically impaired (NI) children using the examiner-based assessment of reliability scoring system and to determine the difference in time to diagnosis of a visual field defect between SCP and a behavioural visual field (BVF) test. Patient records of 115 NI children were retrospectively analysed. The full field peritest (FFP) had best reliability with 44% 'good' scores versus 22% for Goldmann perimetry (p < .001). The mean age of NI children able to perform SCP was 8.3 years versus 4.6 years for the BVF test (p < .001). Use of the BVF test may significantly reduce time to diagnosis.

Uncovering homonymous visual field defects in candidates for pediatric epilepsy surgery

OBJECTIVES

Perimetry in children can be challenging due to low cooperation and short attention span. Especially during the pre-surgical work-up of children with pharmaco-refractory epilepsies, however, diagnosing homonymous visual field defects (HVFDs) can be crucial for planning surgical strategies. Here, we evaluated "campimetry" for visual field testing in children. Furthermore, we analyzed strabismus and anomalous head posture as clinical signs for HVFDs.

METHODS

Campimetry and a standard orthoptic examination were performed in 18 patients (age range: 3 y 2 m-18 y) who underwent epilepsy surgeries in our center during the study period, and in 11 additional patients (age range: 2 y 10 m-22 y 10 m) with suspected or confirmed HVFDs.

RESULTS

In 16/18 patients of our unselected surgery cohort, pre- and postoperative campimetry was successfully completed. Of these, only 7/16 patients had intact visual fields pre- and postoperatively, while 5/16 patients already showed preoperative HVFDs and 4/16 patients suffered newly acquired HVFDs as calculated consequences of the surgery. Regarding clinical signs, strabismus (mostly esotropia) and anomalous head posture were specific indicators of HVFDs (strabismus: 6/12 with HVFDs vs 1/18 without; anomalous head posture: 8/12 with HVFDs vs 0/18 without).

CONCLUSIONS

For perimetry in children with limited cooperation, we suggest campimetry as it allows early detection and fast delineation of HVFDs. This is particularly important in pediatric epilepsy surgery patients, who display a surprisingly high proportion of HVFDs (9/16). Both, strabismus and anomalous head posture can indicate such HVFDs. Therefore, clinicians should pay attention to these clinical signs, especially in the context of epilepsy surgery.

Update on Drug Management of Refractory Epilepsy in Tuberous Sclerosis Complex

Tuberous sclerosis complex (TSC) is a genetic neurocutaneous disorder with epilepsy as a common and early presenting symptom. The neurological phenotype, however, is variable and unpredictable. Early and refractory seizures, infantile spasms in particular, are associated with a poor neurological outcome. Preliminary data suggests early and aggressive seizure control may mitigate the detrimental neurodevelopmental effects of epilepsy. For infantile spasms, vigabatrin is the first line of treatment, and steroids and classic antiepileptic drugs (AEDs) are suitable for second line. Based on retrospective data, vigabatrin should be considered for other indications, especially in infants with focal seizures, as this may prevent infantile spasms, but also in children and adults with epileptic spasms and tonic seizures. Otherwise, for most seizure types, treatment is similar to that for patients without TSC, including the use of novel AEDs, although limited data are available. Three major developments are changing the field of epilepsy management in TSC. First, final recommendations on preventive treatment with vigabatrin will result from two multicenter trials in the US (PREVeNT, clinicaltrials.gov #NCT02849457) and Europe (EPISTOP, clinicaltrials.gov #NCT02098759). Second, treatment with everolimus, an inhibitor of the mechanistic target of rapamycin (mTOR), reduced seizures when compared to placebo. Further, mTOR inhibitors may have an overall disease-modifying effect. Third, the role of cannabidiol in the treatment of refractory seizures in TSC is yet to be established. With treatment recommendations in TSC, we keep an eye on the prize for the broader field of pediatric epilepsy: the lessons learned from TSC are likely applicable to other epileptic encephalopathies.

Visual impairment in children with a brain tumor: a prospective nationwide multicenter study using standard visual testing and optical coherence tomography (CCISS study)

Background

Children with a brain tumor have a high risk of impaired vision. Up to now, visual acuity measurement, visual field testing and orthoptic testing are the most informative diagnostic investigations for the assessment of visual function. Evaluating vision in children can be challenging given the challenges in cooperation, concentration and age-dependent shifts in visual tests. Since visual loss due to a brain tumor can be progressive and irreversible, we must aim to detect visual impairment as early as possible. Several studies have shown that optical coherence tomography facilitates discovery of nerve fiber damage caused by optic nerve glioma. Consequently, early detection of potential ocular damage will effect treatment decisions and will provide timely referral to visual rehabilitation centers.

Methods/design

The CCISS study is a prospective, observational, multicenter cohort study in The Netherlands. Patients aged 0–18 years with a newly diagnosed brain tumor are invited for inclusion in this study. Follow-up visits are planned at 6, 12, 18 and 24 months. Primary endpoints are visual acuity, visual field and optical coherence tomography parameters (retinal nerve fiber layer thickness and ganglion cell layer – inner plexiform layer thickness). Secondary endpoints include the course of visual function (measured by visual acuity, visual field and optical coherence tomography at different follow-up visits), course of the disease and types of treatment.

Discussion

The CCISS study will heighten the awareness of visual impairment in different types of brain tumors in children. This study will show whether optical coherence tomography leads to earlier detection of visual impairment compared to standard ophthalmological testing (i.e. visual acuity, visual field testing) in children with a brain tumor. Furthermore, the systematic approach of ophthalmological follow-up in this study will give us insight in the longitudinal relation between the course of visual function, course of the disease and types of treatment in children with a brain tumor.

Trial registration

The CCISS study is prospectively registered in the Netherlands Trial Register (NTR) since April 2019. Identifier: NL7697.

Cerebral Visual Impairment and Clinical Assessment: The European Perspective

This paper summarizes the multidisciplinary pediatric assessment methods of 3 European centers for identifying and assessing cerebral visual impairment in childhood. It describes a comprehensive neurodevelopmental assessment evaluation in which visual aspects play an important part. Developmental trajectories and the heterogeneity of the clinical picture are emphasized. Multidisciplinary ophthalmology and neurodisability/neurology teamwork together with the parent and teachers, to reach an integrated and individualized perspective for the individual child, are described. This comprehensive assessment is the starting point for habilitation programs and interventions, that can support and meet the child's needs and help them reach their optimal potential. Future developments in classification of the cerebral visual impairment conditions, building on the child's individual assessment profile, will further enhance the direction of clinical, educational, and research progress.

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.

Study of Optimal Perimetric Testing in Children (OPTIC): evaluation of kinetic approaches in childhood neuro-ophthalmic disease

Aims

We compared feasibility, quality and outcomes of visual field (VF) testing in children with neuro-ophthalmic disease between the discontinued ‘gold-standard’ Goldmann and Octopus perimeters.

Methods

Children with neuro-ophthalmic disease, attending Great Ormond Street Hospital, London, were assessed using standardised protocols by one examiner in a single sitting, using Goldmann and Octopus kinetic perimetry. Outputs were classified to compare severity of loss and defect type. Test quality was assessed using both qualitative and quantitative methods.

Results

Thirty children (40% female) aged 5–15 years participated. Goldmann perimetry was completed in full by 90.0% vs 72.4% for Octopus. Inability to plot the blind spot was the most common reason for not completing testing. Over 75% completed a test in ≤20 min. Duration was similar between perimeters (paired t-test, mean difference: 0.48min (−1.2, 2.2), p=0.559). The lowest quality tests were for Octopus perimetry in children <8 years, without significant differences between perimeters in older children (McNemar’s test, χ²=1.0, p=0.317). There was broad agreement between Goldmann and Octopus outputs (good quality, n=21, Bland-Altman, mean difference for isopters I4e (−514.3 deg² (−817.4, –211.2), p=0.814), I2e (−575.5 deg² (−900.1, –250.9), p=0.450) and blind spot (20.8 deg² (5.7, 35.8), p=0.451)). However, VF severity grades and defect type matched in only 57% and 69% of tests, respectively. Octopus perimetry underestimated severe VF defects.

Conclusions

Informative perimetry is feasible in children ≥8 years with neuro-ophthalmic conditions, with either Goldmann or Octopus perimeters. However, meaningful differences exist between the two approaches with implications for consistency in longitudinal assessments.

Gaze-Contingent Flicker Pupil Perimetry Detects Scotomas in Patients With Cerebral Visual Impairments or Glaucoma

Background: The pupillary light reflex is weaker for stimuli presented inside as compared to outside absolute scotomas. Pupillograph perimetry could thus be an objective measure of impaired visual processing. However, the diagnostic accuracy in detecting scotomas has remained unclear. We quantitatively investigated the accuracy of a novel form of pupil perimetry.

Methods: The new perimetry method, termed gaze-contingent flicker pupil perimetry, consists of the repetitive on, and off flickering of a bright disk (2 hz; 320 cd/m²; 4° diameter) on a gray background (160 cd/m²) for 4 seconds per stimulus location. The disk evokes continuous pupil oscillations at the same rate as its flicker frequency, and the oscillatory power of the pupil reflects visual sensitivity. We monocularly presented the disk at a total of 80 locations in the central visual field (max. 15°). The location of the flickering disk moved along with gaze to reduce confounds of eye movements (gaze-contingent paradigm). The test lasted ~5 min per eye and was performed on 7 patients with cerebral visual impairment (CVI), 8 patients with primary open angle glaucoma (age >45), and 14 healthy, age/gender-matched controls.

Results: For all patients, pupil oscillation power (FFT based response amplitude to flicker) was significantly weaker when the flickering disk was presented in the impaired as compared to the intact visual field (CVI: 12%, AUC = 0.73; glaucoma: 9%, AUC = 0.63). Differences in power values between impaired and intact visual fields of patients were larger than differences in power values at corresponding locations in the visual fields of the healthy control group (CVI: AUC = 0.95; glaucoma: AUC = 0.87). Pupil sensitivity maps highlighted large field scotomas and indicated the type of visual field defect (VFD) as initially diagnosed with standard automated perimetry (SAP) fairly accurately in CVI patients but less accurately in glaucoma patients.

Conclusions: We provide the first quantitative and objective evidence of flicker pupil perimetry's potential in detecting CVI-and glaucoma-induced VFDs. Gaze-contingent flicker pupil perimetry is a useful form of objective perimetry and results suggest it can be used to assess large VFDs with young CVI patients whom are unable to perform SAP.

Detection and characterisation of visual field defects using Saccadic Vector Optokinetic Perimetry in children with brain tumours

Purpose

To determine the ability of Saccadic Vector Optokinetic Perimetry (SVOP) to detect and characterise visual field defects in children with brain tumours using eye-tracking technology, as current techniques for assessment of visual fields in young children can be subjective and lack useful detail.

Methods

Case-series study of children receiving treatment and follow-up for brain tumours at the Royal Hospital for Sick Children in Edinburgh from April 2008 to August 2013. Patients underwent SVOP testing and the results were compared with clinically expected visual field patterns determined by a consensus panel after review of clinical findings, neuroimaging, and where possible other forms of visual field assessment.

Results

Sixteen patients participated in this study (mean age of 7.2 years; range 2.9–15 years; 7 male, 9 female). Twelve children (75%) successfully performed SVOP testing. SVOP had a sensitivity of 100% and a specificity of 50% (positive predictive value of 80% and negative predictive value of 100%). In the true positive and true negative SVOP results, the characteristics of the SVOP plots showed agreement with the expected visual field. Six patients were able to perform both SVOP and Goldmann perimetry, these demonstrated similar visual fields in every case.

Conclusion

SVOP is a highly sensitive test that may prove to be extremely useful for assessing the visual field in young children with brain tumours, as it is able to characterise the central 30° of visual field in greater detail than previously possible with older techniques.

Pediatric Perimeter-A Novel Device to Measure Visual Fields in Infants and Patients with Special Needs

PURPOSE

There are no commercially available devices to measure visual fields in infants. We developed a device, "Pediatric Perimeter," that quantifies visual field extent (VFE) for infants. We describe the construction, validation, and use of this device.

METHODS

A hemispherical dome with light emitting diodes (LEDs) was constructed. The LEDs were controlled using a computer program to measure reaction time (RT) to gross visual fields (GVF) and the VFE. Participants were tested in supine position in a dark room. Eye or head movement towards the stimuli was monitored with an infrared (IR) camera. Validation was done on 10 adults (mean age: 24.4 ± 5 years) with tunnel vision simulator.

RESULTS

Perimetry was performed on 19 infants (age: 2.3-12 months), five infants with normal milestones. GVF and VFE were estimated in 17 and 7 infants, respectively. Median RT of infants with developmental delay was 663 ms and 380 ms for healthy infants. Also, 14 children (age: 14 months-6 years) with developmental delay and five patients with cognitive impairment were tested.

CONCLUSION

Visual field isopter and RT can be examined with the Pediatric Perimeter device on infants and patients with special needs. Further testing on infants will need to assess the repeatability. A large-scale study will be needed to compare typically developing infants and infants with delayed milestones with this device.

TRANSLATIONAL RELEVANCE

Quantifiable parameters obtained with this device can be used as outcome measures in clinical examination of infants and patients with special needs. This device can be used in pediatric, neurology, and ophthalmology clinics.

Visual outcome in Sturge-Weber syndrome: a systematic review and Dutch multicentre cohort

Visual functions in Sturge-Weber syndrome (SWS) may be impaired by glaucoma, diffuse choroidal haemangioma (DCH) or leptomeningeal angioma. The aim of this study was to gain better insight in the visual deficits of SWS patients. A systematic literature search using PubMed and Embase medical databases was performed to identify articles describing visual acuity (VA) and/or visual field (VF) findings in SWS patients. In addition, a Dutch multicentre cohort with 33 SWS patients was collected and the combined results of VA and VF findings are presented. Visual acuity results of 25 studies and VF results of 12 studies were suitable for data extraction. Description of the combination of both VA and VF findings was scarce. Homonymous hemianopia (HH) was present in 42% of SWS patients. Seventy per cent of eyes had a (near) normal vision, while VA of eyes with glaucoma or DCH was severely impaired in 28% and 67%, respectively. In the Dutch cohort, only 18% (6/33) of patients had (near) normal findings of both visual parameters. In addition, half of the patients with glaucoma suffered from a combination of a HH and VA impairment. In conclusion, although SWS patients are exposed to severe functional visual impairment due to the possible cumulative consequences of glaucoma, DCH and cerebral injury, description of the combination of both VA and VF results is scarce in the literature. Particularly, the combination of visual impairment due to glaucoma or DCH, and HH might be invalidating.

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.

Neurofibromatosis: an update of ophthalmic characteristics and applications of optical coherence tomography

Neurofibromatosis (NF) is a multisystem disorder and tumor predisposition syndrome caused by genetic mutation on chromosome 17-17q11.2 in NF type 1 (NF1), and on chromosome 22-22q12.2 in NF type 2. The disorder is characterized by considerable heterogeneity of clinical expression. NF1 is the form with the most characteristic ocular manifestations. Lisch nodules of the iris are among the well-known diagnostic criteria for the disease. Glaucoma and associated globe enlargement have been described in a significant proportion of patients with NF1 and orbital–facial involvement. Optic nerve glioma may cause strabismus and proptosis, and palpebral neurofibroma may reach considerable size and occasionally show malignant transformation. Near infrared reflectance has greatly contributed to enhancing our knowledge on choroidal alterations in NF1. Indeed, some authors have proposed to include these among the diagnostic criteria. Optical coherence tomography has given new insight on retinal alterations and is a noninvasive tool in the management of optic nerve gliomas in children. Ocular manifestations in NF type 2 can range from early-onset cataracts in up to 80% of cases to optic nerve hamartomas and combined pigment epithelial and retinal hamartomas.

Saccadic vector optokinetic perimetry in children with neurodisability or isolated visual pathway lesions: observational cohort study

BACKGROUND/AIMS

Children and adults with neurological impairments are often not able to access conventional perimetry; however, information about the visual field is valuable. A new technology, saccadic vector optokinetic perimetry (SVOP), may have improved accessibility, but its accuracy has not been evaluated. We aimed to explore accessibility, testability and accuracy of SVOP in children with neurodisability or isolated visual pathway deficits.

METHODS

Cohort study; recruitment October 2013-May 2014, at children's eye clinics at a tertiary referral centre and a regional Child Development Centre; full orthoptic assessment, SVOP (central 30° of the visual field) and confrontation visual fields (CVF). Group 1: age 1-16 years, neurodisability (n=16), group 2: age 10-16 years, confirmed or suspected visual field defect (n=21); group 2 also completed Goldmann visual field testing (GVFT).

RESULTS

Group 1: testability with a full 40-point test protocol is 12.5%; with reduced test protocols, testability is 100%, but plots may be clinically meaningless. Children (44%) and parents/carers (62.5%) find the test easy. SVOP and CVF agree in 50%. Group 2: testability is 62% for the 40-point protocol, and 90.5% for reduced protocols. Corneal changes in childhood glaucoma interfere with SVOP testing. All children and parents/carers find SVOP easy. Overall agreement with GVFT is 64.7%.

CONCLUSIONS

While SVOP is highly accessible to children, many cannot complete a full 40-point test. Agreement with current standard tests is moderate to poor. Abnormal saccades cause an apparent non-specific visual field defect. In children with glaucoma or nystagmus SVOP calibration often fails.

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.