Intra- and inter-visit reproducibility of ganglion cell-inner plexiform layer measurements using handheld optical coherence tomography in children with optic pathway gliomas

Longitudinal changes in retinal ganglion cell function in optic pathway glioma evaluated by photopic negative response

Photopic negative response (PhNR), an index of retinal ganglion cell (RGC) function, is impaired in patients with optic pathway gliomas (OPGs). The aim of this longitudinal study was to evaluate whether PhNR deteriorates over time in OPG patients. Fourteen pediatric patients affected by OPG (4 males and 10 females, mean age 12.4 ± 5.7 years, 8 with neurofibromatosis type 1 [NF1]) with ≥12 months of follow-up and ≥2 evaluations, were included in this retrospective study. All patients had received chemotherapy, with or without OPG surgical resection, at least 5 years prior to the study. At baseline, all patients underwent a complete ophthalmological examination. Follow-up included clinical examination and PhNR measurement as well as brain MRI (according to pediatric oncologist indications) every 6 or 12 months. Mean follow-up duration was 16.7 ± 7.5 months (range 12-36 months). Photopic electroretinograms were elicited by 2.0 cd-s/m2 Ganzfeld white flashes presented on a steady 20 cd/m2 white background. The PhNR amplitude was measured as the difference between baseline and the maximal negative amplitude (minimum) of the negative wave, following the photopic b-wave. Compared to baseline, mean PhNR amplitude was significantly decreased at the end of follow-up (p = 0.008). NF1-related OPGs exhibited a decline in PhNR amplitude (p = 0.005) and an increase in PhNR peak-time during the follow-up (p = 0.013), whereas sporadic OPGs showed no significant changes. Tumor size remained stable in all patients on MRI. PhNR amplitude decreased over the observation period, suggesting progressive RGC dysfunction in NF1-related pediatric OPGs, despite stable size on MRI imaging. PhNR could serve as a non-invasive objective tool for assessing longitudinal changes in RGC function in the clinical management of childhood OPG.

Optical coherence tomography of the macular ganglion cell layer in children with neurofibromatosis type 1 is a useful tool in the assessment for optic pathway gliomas

BACKGROUND

Optic pathway glioma (OPG) is a feared complication to neurofibromatosis type 1 (NF1) since it can cause visual impairment in young children. The main goal of screening is to detect symptomatic OPGs that require treatment. Optical coherence tomography (OCT) has been suggested as a tool for detection of neuro-retinal damage.

AIMS

To investigate whether the ganglion cell layer assessed by OCT is a reliable measure to identify and detect relapses of symptomatic OPGs in children with NF1.

METHODS

Children (3-6 years) with NF1, with and without known OPG and children with sporadic OPG (S-OPG) resident in the Stockholm area, were invited and followed in a prospective study during a three-year period. Brain magnetic resonance tomography (MRI) had been performed in children with symptoms of OPG. Outcome measures were VA in logMAR, visual field index (VFI), average thicknesses of the ganglion cell-inner plexiform layer (GC-IPL), and peripapillary retinal nerve fiber layer (pRNFL).

RESULTS

There were 25 children with MRI-verified OPG and 52 with NF1 without symptomatic OPG. Eyes from NF1 patients without symptoms of OPG showed significantly better results in all four analyzed parameters compared to eyes with NF1-associated OPG. Mean GC-IPL measurements seemed stable and reliable, significantly correlated to pRNFL (correlation coefficient (r) = 0.662, confidence interval (CI) = .507 to .773 p<0.001), VA (r = -0.661, CI = -7.45 to -.551, p<0.001) and VFI (r = 0.644, CI = .452 to .774, p<0.001). GC-IPL measurements were easy to obtain and acquired at considerably younger age than pRNFL (5.6±1.5 vs 6.8±1.3; p<0.001).

CONCLUSIONS

The mean GC-IPL thickness could distinguish well between eyes with OPG and eyes without symptomatic OPG in children with NF1. As thinning of GC-IPL assessed with OCT could indicate underlying OPG, it should be included in the screening protocol of children with questionable VA measurements and in particular in children with NF1.

Sensitivity, Specificity, and Cutoff Identifying Optic Atrophy by Macular Ganglion Cell Layer Volume in Syndromic Craniosynostosis

PURPOSE

To determine the sensitivity, specificity, and cutoff of macular ganglion cell layer (GCL) volume consistent with optic atrophy in children with syndromic craniosynostosis and to investigate factors independently associated with reduction in GCL volume.

DESIGN

Retrospective cross-sectional study.

PARTICIPANTS

Patients with syndromic craniosynostosis evaluated at Boston Children's Hospital (2010-2022) with reliable macular OCT scans.

METHODS

The latest ophthalmic examination that included OCT macula scans was identified. Age at examination, sex, ethnicity, best-corrected logarithm of the minimum angle of resolution (logMAR) visual acuity, cycloplegic refraction, and funduscopic optic nerve appearance were recorded in addition to history of primary or recurrent elevation in intracranial pressure (ICP), Chiari malformation, and obstructive sleep apnea (OSA). Spectral-domain OCT software quantified segmentation of macula retinal layers and was checked manually.

MAIN OUTCOME MEASURES

The primary outcome was determining sensitivity, specificity, and optimal cutoff of GCL volume consistent with optic atrophy. The secondary outcome was determining whether previously elevated ICP, OSA, Chiari malformation, craniosynostosis diagnosis, logMAR visual acuity, age, or sex were independently associated with lower GCL volume.

RESULTS

Median age at examination was 11.9 years (interquartile range, 8.5-14.8 years). Fifty-eight of 61 patients (112 eyes) had reliable macula scans, 74% were female, and syndromes represented were Apert (n = 14), Crouzon (n = 17), Muenke (n = 6), Pfeiffer (n = 6), and Saethre-Chotzen (n = 15). Optimal cutoff identifying optic atrophy was a GCL volume < 1.02 mm3 with a sensitivity of 83% and specificity of 77%. Univariate analysis demonstrated that significantly lower macular GCL volume was associated with optic atrophy on fundus examination (P < 0.001), Apert syndrome (P < 0.001), history of elevated ICP (P = 0.015), Chiari malformation (P = 0.001), OSA (P < 0.001), male sex (P = 0.027), and worse logMAR visual acuity (P < 0.001). Multivariable median regression analysis confirmed that only OSA (P = 0.005), optic atrophy on fundus examination (P = 0.003), and worse logMAR visual acuity (P = 0.042) were independently associated with lower GCL volume.

CONCLUSIONS

Surveillance for optic atrophy by GCL volume may be useful in a population where cognitive skills can limit acquisition of other key ophthalmic measures. It is noteworthy that OSA is also associated with lower GLC volume in this population.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Determining relative thickness of inner retinal layers on single-line foveal optical coherence tomography (OCT) in healthy pediatric eyes-normative data for handheld OCT

BACKGROUND

Handheld optical coherence tomography (HH-OCT) lacks integrated segmentation/analysis software. Optic neuropathies cause ganglion cell layer (GCL) thinning, with normal to thickened inner nuclear layer (INL), suggesting the potential value of estimating the GCL/INL ratio on single-line foveal HH-OCT scans. This study determines this ratio in macular scans from healthy eyes of young children using HH-OCT and overhead-mounted OCT.

METHODS

Macular OCT scans were obtained using either HH-OCT or overhead-mounted Spectralis FLEX-OCT in children ages 0-5 years undergoing clinically indicated anesthesia/sedation. Exclusion criteria included gestational age <37 weeks, neurologic disease, amblyopia, ocular disease, or large refractive error (spherical equivalent beyond -3.00 D to +8.00 D). For HH-OCT, the GCL and INL were manually measured in pixels from single-line macular scans at the thickest point nasal and temporal to the fovea. For FLEX-OCT images, measurements were aided by automated software.

RESULTS

HH-OCT was obtained on 38 eyes (38 children, mean age 2.4 ± 1.8 years) and FLEX-OCT on 56 eyes (56 children, mean age 2.3 ± 1.5 years). Mean nasal GCL/INL was 1.24 ± 0.18 (min/max = 0.92/1.75) for HH-OCT and 1.29 ± 0.18 (min/max = 0.96/1.66) for FLEX-OCT (P = 0.11). Mean temporal GCL/INL was 1.22 ± 0.24 (min/max = 0.66/1.70) for HH-OCT and 1.19 ± 0.16 (min/max = 0.86/1.47) for FLEX-OCT (P = 0.47).

CONCLUSIONS

Mean normative GCL/INL ratios were approximately 1.2 at the thickest macular areas both nasal and temporal to the fovea, with either HH-OCT or FLEX-OCT in young children's eyes. These values may prove useful when HH-OCT is used to assess optic neuropathies, in which the GCL/INL ratio is expected to be decreased.

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.

Macular imaging with optical coherence tomography in glaucoma

With the advent of spectral-domain optical coherence tomography, imaging of the posterior segment of the eye can be carried out rapidly at multiple anatomical locations, including the optic nerve head, circumpapillary retinal nerve fiber layer, and macula. There is now ample evidence to support the role of spectral-domain optical coherence tomography imaging of the macula for detection of early glaucoma. Macular spectral-domain optical coherence tomography measurements demonstrate high reproducibility, and evidence on its utility for detection of glaucoma progression is accumulating. We present a comprehensive review of macular spectral-domain optical coherence tomography imaging emerging as an essential diagnostic tool in glaucoma.

Ocular manifestations in phakomatosis pigmentovascularis: Current concepts on pathogenesis, diagnosis, and management

Phakomatosis pigmentovascularis is a rare congenital multisystemic disease with variable manifestations where a vascular malformation of the skin is associated with a pigmentary nevus. Ocular involvement includes glaucoma, choroidal hemangioma, and pigmentary alterations that predispose to uveal melanoma. Diagnosis is made on clinical grounds, although recent advances in molecular genetics have better clarified the etiopathogenesis of the condition. The advent of improved imaging techniques such as enhanced depth imaging spectral domain optical coherence tomography has provided new insight into the ocular alterations, enabling better follow-up of patients. We review the ophthalmic manifestations of the disease with an update on etiopathogenesis and current management strategies.

Interobserver reproducibility and interocular symmetry of the macular ganglion cell complex: assessment in healthy children using optical coherence tomography

Background

Assessment of interobserver reproducibility and interocular symmetry using optical coherence tomography (OCT)–based measurements of the macular ganglion cell complex (GCC) in healthy children facilitates interpretation of OCT data. We assessed the interobserver reproducibility and interocular symmetry of GCC and evaluated candidate determinants.

Methods

This was a cross-sectional study performed in a primary and tertiary health-care setting. A total of 126 healthy participants aged 5 to 18 years were eligible. GCC scans were performed by 4 operators using the Topcon 3D OCT-2000 device. Intraclass correlation coefficients (ICCs) were used to estimate reproducibility and symmetry. Cut-off points for symmetry were defined as the 95th percentile of the absolute interocular difference for 6 GCC parameters. Percentile distributions of interocular difference were generated based on age and difference in absolute interocular spherical equivalent (SE).

Results

The reproducibility ICC ranged from 0.96 to 0.98 for all 6 GCC parameters. Cut-off points for interocular symmetry of the superior and inferior quadrants and total macular retinal nerve fibre layer thickness (mRNFL) and macular ganglion cell layer-inner plexiform layer thickness were 3.5, 4.5, 3.0, 3.0, 2.5, and 2.5 μm respectively. A positive association was observed between the absolute interocular difference of SE and superior and total mRNFL symmetry values (p = 0.047 and p = 0.040, respectively).

Conclusions

OCT measurements of GCC in healthy children show excellent reproducibility. Interocular differences in SE should be assessed when mRNFL differences exceed the 95% cut-off. These findings can contribute to establish reference values for interocular symmetry in paediatric GCC parameters.

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.

Handheld Optical Coherence Tomography Normative Inner Retinal Layer Measurements for Children <5 Years of Age

PURPOSE

Measurements of the ganglion cell complex (GCC), comprising the retinal nerve fiber (RNFL), ganglion cell, and inner plexiform layers, can be correlated with vision loss caused by optic nerve disease. Handheld optical coherence tomography (HH-OCT) can be used with sedation in children who are not amenable to traditional imaging. We report GCC and RNFL measurements in normal children using HH-OCT.

DESIGN

Prospective observational study of normal children ≤5 years of age.

METHODS

Healthy, full-term children ≤5 years of age undergoing sedation or anesthesia were enrolled. Exclusion criteria included prematurity and pre-existing neurologic, genetic, metabolic, or intraocular pathology. Demographic data, axial length (Master-Vu Sonomed Escalon, Lake Success, New York, USA), and HH-OCT macular and optic nerve volume scans at 0° (Bioptigen, Inc., Morrisville, North Carolina, USA) were obtained. Retinal segmentation was completed with DOCTRAP software, creating average volume thickness maps.

RESULTS

Sixty-seven children (67 eyes, 31 males ranging in age from 3.4-70.9 months) were enrolled. Average axial length was 21.2 ± 1.0 mm with mean spherical equivalent +1.49 ± 1.34 diopters (range -2.25 to 4.25). Average GCC volume for the total retina was 0.28 ± 0.04 mm³. Forty-seven of these eyes had RNFL analysis. Average RNFL thickness of the papillomacular bundle was 38.2 ± 9.5 μm. There was no correlation between GCC volume, RNFL thickness, patient age, or axial length.

CONCLUSION

Average GCC volume and RNFL thickness was stable from 6 months to 5 years of age. This study provides normative data for GCC and RNFL obtained by HH-OCT in healthy eyes of young children, to serve in evaluating those with optic neuropathies.

Bilateral diffuse choroidal hemangioma in Sturge Weber syndrome: A case report highlighting the role of multimodal imaging and a brief review of the literature

PURPOSE

To present a patient with bilateral choroidal hemangioma in Sturge-Weber syndrome (SWS) and highlight multimodal imaging techniques for early detection and management of ocular alterations.

METHODS

A 37-year-old woman with diagnosis of SWS presented to our unit. The patient had been treated with pulsed dye laser for bilateral nevus flammeus and had right leptomeningeal angiomatosis. She had glaucoma, but ultrasound biomicroscopy did not show anterior chamber or ciliary body alterations.

RESULTS

Enhanced depth imaging (EDI) spectral domain optical coherence tomography (SD-OCT) showed bilateral diffuse choroidal hemangiomas in both eyes with choroidal thickness above 1000 μm. B-scan ultrasound examination showed diffuse choroidal hemangioma in both eyes, with a choroidal thickness of 1.53 mm and 1.94 mm in the right and left eye (RE, LE), respectively. Peripapillary retinal nerve fiber evaluation showed thinning of the retinal nerve fiber layer in both eyes.

CONCLUSIONS

This report highlights multimodal imaging techniques for the critical assessment of patients with SWS, especially in rare cases with bilateral choroidal hemangioma of the choroid. Novel imaging modalities enable optimal management and follow-up of rare conditions, and our case adds further evidence to the existing literature.

Optical coherence tomography in paediatric clinical practice

Optical coherence tomography is a non-invasive ocular imaging technique that is frequently used in the diagnosis and monitoring of optic nerve or retinal disease. Advances in optical coherence tomography speed and image processing capability allow increased use of the modality in clinical practice, especially in younger children. This review outlines the challenges involved in imaging children, highlights the technological progress, the importance of acquiring normative data and, finally, focuses on the clinical applicability of optical coherence tomography in our paediatric population with various ocular conditions.

Use of Optical Coherence Tomography to Detect Retinal Nerve Fiber Loss in Children With Optic Pathway Glioma

Optic pathway glioma (OPG) presents in childhood and can cause significant morbidity and visual loss. Magnetic resonance imaging (MRI) is the current imaging modality of choice for evaluation of OPG progression, but it is a relatively limited resource often requiring sedation in the pediatric age group. Additionally, OPG progression on MRI does not always correlate with clinical progression. As a result, several other modalities for evaluating OPG are being investigated, including optical coherence tomography (OCT), a readily available imaging technique in ophthalmic practice. The purpose of the present study was to examine the association between retinal nerve fiber layer (RNFL) thickness measured using OCT and optic nerve function in children with OPG with and without neurofibromatosis-1 (NF-1). A retrospective chart review was conducted to identify children diagnosed with OPG from 2001 to 2015 at a tertiary pediatric medical center. The correlation between OCT measurements and clinical visual parameters was statistically analyzed. Included were 23 children with imaging-confirmed OPG and spectral domain OCT: 10 with NF-1 (mean age at diagnosis 5.8 years) and 13 without (mean age at diagnosis 5.9 years). The glioma involved the chiasma-hypothalamus in 19 patients, optic nerve in 11, and optic tract in 7; more than one anatomic site was affected in 15. Symptoms were reported in 2 patients with NF-1 and most patients without NF-1. Visual field defects included monocular, bitemporal, nasal, and homonymous hemianopia. Initial mean RNFL was 85.4 μm in the NF-1 group and 65 μm in the non-NF-1 group. Visual acuity deteriorated in 1/10 patients and 5/13 patients, respectively. Repeated OCT showed continued RNFL thinning in 3 patients (5 eyes) in the NF-1 group and in 8 patients (11 eyes) in the non-NF-1 group, often associated with a decrease in optic nerve function. In conclusion, visual function in children with OPG is correlated with repeated OCT measurements and weakly with neuroimaging. Children without NF-1 are usually symptomatic and have a worse clinical outcome. These findings may have important implications when considering initiating, continuing or stopping chemotherapy for OPG. The application of OCT in the assessment of OPG and the correlation of the findings to clinical progression can have a significant impact on OPG patient management.

OCT Angiography: A Technique for the Assessment of Retinal and Optic Nerve Diseases in the Pediatric Population

Optical coherence tomography angiography (OCT-A) is a novel, rapidly evolving, non-invasive imaging technique that allows images of the retinal vasculature to be obtained in a few seconds. Blood vessels of different retinal vascular plexuses and the foveal avascular zone (FAZ) can be examined without the administration of any contrast or dye. Due to these characteristics, OCT-A could be an excellent complementary test to study retinal vascularization in children. Until now, most of the studies with OCT-A have been conducted in adults and only a few have been carried out in children. In this review, we describe the principles and advantages of OCT-A over traditional imaging methods and provide a summary of the OCT-A findings in retinopathy of prematurity and other retinal and optic disc pathologies in children. In view of the promising results from studies, the advantages of a relatively rapid and non-invasive method to assess the retinal vasculature makes OCT-A a tool of which applications in the field of pediatric ophthalmology will be expanded in the near future for patient diagnosis and follow-up in every day clinical practice.

Assessment of macular ganglion cell complex using optical coherence tomography: Impact of a paediatric reference database in clinical practice

IMPORTANCE

Optical coherence tomography software classifies abnormality of macular ganglion cell-inner plexiform layer thickness and macular retinal nerve fibre layer thickness based on adult series.

BACKGROUND

We assessed the impact of using paediatric reference macular ganglion cell complex values instead of adult reference values.

DESIGN

Cross-sectional study. Primary and tertiary health-care setting.

PARTICIPANTS

Out of 140 healthy participants aged 5 to 18 years, 90% were eligible.

METHODS

Following a dilated eye examination and cycloplegic refraction, participants underwent optical coherence tomography ganglion cell scans (Topcon 3D OCT-2000; Topcon Corporation, Tokyo, Japan). Right eye measurements for superior, inferior, and total layer thickness and spherical equivalent were reported, together with age, sex and origin.

MAIN OUTCOME MEASURES

Paediatric reference values by age and spherical equivalent were produced, and the specific agreement between paediatric and adult ganglion cell complex reference values below or equal to percentile 5 was estimated.

RESULTS

The multivariate analysis confirmed a positive association between spherical equivalent and macular ganglion cell-inner plexiform layer thickness, and between age and macular retinal nerve fibre layer (five out of six regression coefficients P values were ≤ 0.03). Specific agreement was 25% for ganglion cell-inner plexiform layer thickness and > 80% for macular retinal nerve fibre layer. Adult-based software identified low ganglion cell values in one in seven children compared to paediatric reference values (0.8% vs 5.5%, P = 0.031).

CONCLUSIONS AND RELEVANCE

The availability of optical coherence tomography ganglion cell complex reference values for paediatric age and spherical equivalent groups can be used to improve detection of children with low cell layer thickness.

Ophthalmic manifestations in neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is a relatively common multisystemic inherited disease and has been extensively studied by multiple disciplines. Although genetic testing and confirmation are available, NF1 remains a clinical diagnosis. Many manifestations of NF1 involve the eye and orbit, and the ophthalmologist, therefore, plays a significant role in the diagnosis and treatment of NF1 patients. Improvements in diagnostic and imaging instruments have provided new insight to study the ophthalmic manifestations of the disease. We provide a comprehensive and up-to-date overview of the ocular and orbital manifestations of NF1.

Cancer and Central Nervous System Tumor Surveillance in Pediatric Neurofibromatosis 1

Although the neurofibromatoses consist of at least three autosomal dominantly inherited disorders, neurofibromatosis 1 (NF1), neurofibromatosis 2 (NF2), and schwannomatosis, NF1 represents a multisystem pleiotropic condition very different from the other two. NF1 is a genetic syndrome first manifesting in childhood; affecting multiple organs, childhood development, and neurocognitive status; and presenting the clinician with often complex management decisions that require a multidisciplinary approach. Molecular genetic testing (see article for detailed discussion) is recommended to confirm NF1, particularly in children fulfilling only pigmentary features of the diagnostic criteria. Although cancer risk is not the major issue facing an individual with NF1 during childhood, the condition causes significantly increased malignancy risks compared with the general population. Specifically, NF1 is associated with highly elevated risks of juvenile myelomonocytic leukemia, rhabdomyosarcoma, and malignant peripheral nerve sheath tumor as well as substantial risks of noninvasive pilocytic astrocytoma, particularly optic pathway glioma (OPG), which represent a major management issue. Until 8 years of age, clinical assessment for OPG is advised every 6 to 12 months, but routine MRI assessment is not currently advised in asymptomatic individuals with NF1 and no signs of clinical visual pathway disturbance. Routine surveillance for other malignancies is not recommended, but clinicians and parents should be aware of the small risks (<1%) of certain specific individual malignancies (e.g., rhabdomyosarcoma). Tumors do contribute to both morbidity and mortality, especially later in life. A single whole-body MRI should be considered at transition to adulthood to assist in determining approaches to long-term follow-up. Clin Cancer Res; 23(12); e46-e53. ©2017 AACRSee all articles in the online-only CCR Pediatric Oncology Series.

Optical coherence tomography as a marker of vision in children with optic pathway gliomas

PURPOSE

Optic pathway gliomas (OPG) represent an important cause of visual loss in pediatric population. The indication of treatment is based on clinical or neuroimaging progression. Visual acuity loss is the most important symptom of disease progression, but children with OPG are frequently unable to complete the testing of visual function. Optical coherence tomography (OCT) was suggested as an objective tool for visual assessment. A literature review was performed in order to determine the role of retinal OCT as a surrogate marker of vision in children with OPG.

METHODS

The search was performed using PubMed, Embase, and Web of Science databases and was restricted to articles published in English between 2000 and 2016, with a minimum of ten participants enrolled.

RESULTS

Eleven studies met the eligibility criteria and were included in the present review. Both neurofibromatosis-1 associated and sporadic OPG were investigated.

CONCLUSIONS

Retinal OCT is a promising tool to be considered as a screening or follow-up test in children with OPG, and further multicenter research is encouraged.

Measurements of Retinal Nerve Fiber Thickness and Ganglion Cell Complex in Neurofibromatosis Type 1, with and Without Optic Pathway Gliomas: A Case Series

PURPOSE

The aim of this study was to investigate differences in retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) thicknesses in neurofibromatosis 1 (NF1) cases, with and without optic pathway gliomas (OPGs).

MATERIALS AND METHODS

In total, 33 eyes of 33 subjects were evaluated in this prospective observational case series. Twenty-one patients with a diagnosis of NF1 were enrolled. Patients with NF1 and OPGs were included in Group 1 (n = 9), and patients with NF1 without OPGs were included in Group 2 (n = 12). The control group (Group 3) was comprised of 12 age- and sex-matched subjects with no history of ophthalmic or systemic diseases. All of the subjects underwent complete ophthalmic examinations, including best-corrected visual acuity (BCVA), slit lamp microscopy, and indirect ophthalmoscopy. Additionally, optical coherence tomography (OCT) measurements were obtained.

RESULTS

There were no statistically significant between-group differences in age and sex (p = 0.227 and 0.986, respectively). The average RNFL thickness in Group 1 (NF1 patients with OPGs) was significantly lower than in Groups 2 and 3 (86.6 ± 22.5, 107.4 ± 6.65, and 108.4 ± 5.05 µm, respectively; p = 0.001). Furthermore, the average GCC thickness in Group 1 was significantly lower than in Groups 2 and 3 (78.6 ± 16.3, 94.8 ± 3.55, and 94.9 ± 3.82 µm, respectively; p < 0.001).

CONCLUSIONS

Both RNFL and GCC thicknesses were significantly lower in NF1 patients with OPGs. The use of OCT to quantify damage to the visual pathway may enable earlier detection of OPGs in NF1 patients.

Optic Pathway Gliomas in Neurofibromatosis Type 1: An Update: Surveillance, Treatment Indications, and Biomarkers of Vision

Optic pathway gliomas (OPGs) occur in 15%-20% of children with neurofibromatosis type 1 (NF1), leading to visual deficits in fewer than half of these individuals. The goal of chemotherapy is to preserve vision, but vision loss in NF1-associated OPG can be unpredictable. Determining which child would benefit from chemotherapy and, equally important, which child is better observed without treatment can be difficult. Unfortunately, despite frequent imaging and ophthalmologic evaluations, some children experience progressive vision loss before treatment. Indications for chemotherapy usually are based on a comprehensive, quantitative assessment of vision, but reliable vision evaluation can be challenging in young children with NF1-OPG. The ability to identify and predict impending vision loss could potentially improve management decisions and visual outcomes. To address this challenge, ophthalmologic, electrophysiologic, and imaging biomarkers of vision in NF1-OPG have been proposed. We review current recommendations for the surveillance of children at risk for NF1-OPG, outline guidelines for initiating therapy, and describe the utility of proposed biomarkers for vision.

Sturge-Weber Syndrome Associated with Monolateral Ocular Melanocytosis, Iris Mammillations, and Diffuse Choroidal Haemangioma

We present the case of a 12-year-old boy with Sturge-Weber syndrome and ocular melanocytosis who presented with bilateral naevus flammeus of the face and hyperpigmentation of the right iris associated with ipsilateral iris mammillations. The patient had glaucoma and a diffuse choroidal haemangioma of the right eye. Optical coherence tomography of the anterior segment confirmed iris hyper-pigmentation and did not show abnormalities of the chamber angle structures. B-scan ultrasonography and enhanced depth imaging optical coherence tomography were performed and showed a marked difference in thickness and reflectance between the right and left choroid. Visual field examinations with perimetry showed early defects in the right eye. Peripapillary optical coherence imaging showed borderline values of retinal nerve fibre layer thickness reduction in the right eye. Sturge-Weber syndrome associated with ocular melanocytosis and iris mammillations is an extremely rare condition. This paper highlights the role of multi-imaging methods in the enhanced evaluation of rare diseases towards choosing the most appropriate management strategies and improving the follow-up of patients over time.

Volume Averaging of Spectral-Domain Optical Coherence Tomography Impacts Retinal Segmentation in Children

PURPOSE

To determine the influence of volume averaging on retinal layer thickness measures acquired with spectral-domain optical coherence tomography (SD-OCT) in children.

METHODS

Macular SD-OCT images were acquired using three different volume settings (i.e., 1, 3, and 9 volumes) in children enrolled in a prospective OCT study. Total retinal thickness and five inner layers were measured around an Early Treatment Diabetic Retinopathy Scale (ETDRS) grid using beta version automated segmentation software for the Spectralis. The magnitude of manual segmentation required to correct the automated segmentation was classified as either minor (<12 lines adjusted), moderate (>12 and <25 lines adjusted), severe (>26 and <48 lines adjusted), or fail (>48 lines adjusted or could not adjust due to poor image quality). The frequency of each edit classification was assessed for each volume setting. Thickness, paired difference, and 95% limits of agreement of each anatomic quadrant were compared across volume density.

RESULTS

Seventy-five subjects (median age 11.8 years, range 4.3-18.5 years) contributed 75 eyes. Less than 5% of the 9- and 3-volume scans required more than minor manual segmentation corrections, compared with 71% of 1-volume scans. The inner (3 mm) region demonstrated similar measures across all layers, regardless of volume number. The 1-volume scans demonstrated greater variability of the retinal nerve fiber layer (RNLF) thickness, compared with the other volumes in the outer (6 mm) region.

CONCLUSIONS

In children, volume averaging of SD-OCT acquisitions reduce retinal layer segmentation errors.

TRANSLATIONAL RELEVANCE

This study highlights the importance of volume averaging when acquiring macula volumes intended for multilayer segmentation.

An Update on the Ophthalmologic Features in the Phakomatoses

Neurofibromatosis type 1, tuberous sclerosis complex, and Von Hippel-Lindau disease, historically classified as the phakomatoses, are hereditary multisystem disorders characterized by the presence of hamartoma, which carry the risk of malignant transformation. The alteration of tumor suppressor genes seems to be at the basis of their pathophysiogenetic mechanism. Lisch and choroidal nodules in neurofibromatosis type 1, retinal astrocytomas in tuberous sclerosis complex, and retinal capillary hemangioma in Von Hippel-Lindau disease are the principal ophthalmic hamartomatous manifestations. The advent of novel imaging techniques such as near infrared reflectance and optical coherence tomography has provided unprecedented insight on the choroidal and retinal features of these diseases. These methods have improved early diagnosis and the ongoing surveillance in these conditions. Among an array of treatment modalities, antivascular endothelial growth factor therapy has been used in the management of retinal hamartomas but results have been varied. This review is an update on the pathophysiogenetic mechanisms, ophthalmic manifestations, and novel treatment strategies in the phakomatoses with emphasis on the role of imaging techniques.

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.

Applications of optical coherence tomography in pediatric clinical neuroscience

For nearly two centuries, the ophthalmoscope has permitted examination of the retina and optic nerve-the only axons directly visualized by the physician. The retinal ganglion cells project their axons, which travel along the innermost retina to form the optic nerve, marking the beginning of the anterior visual pathway. Both the structure and function of the visual pathway are essential components of the neurologic examination as it can be involved in numerous acquired, congenital and genetic central nervous system conditions. The development of optical coherence tomography now permits the pediatric neuroscientist to visualize and quantify the optic nerve and retinal layers with unprecedented resolution. As optical coherence tomography becomes more accessible and integrated into research and clinical care, the pediatric neuroscientist may have the opportunity to utilize and/or interpret results from this device. This review describes the basic technical features of optical coherence tomography and highlights its potential clinical and research applications in pediatric clinical neuroscience including optic nerve swelling, optic neuritis, tumors of the visual pathway, vigabatrin toxicity, nystagmus, and neurodegenerative conditions.