Publications by authors named "Richard Bowman"

119 Publications

Feasibility and Repeatability of Handheld Optical Coherence Tomography in Children With Craniosynostosis.

Transl Vis Sci Technol 2021 Jul;10(8):24

The University of Leicester Ulverscroft Eye Unit, Leicester Royal Infirmary, Leicester, UK.

Purpose: To determine whether handheld optical coherence tomography (OCT) is feasible and repeatable in children with craniosynostosis.

Methods: This was a prospective cross-sectional study. Children with syndromic and non-syndromic craniosynostosis 0 to 18 years of age were recruited between February 13, 2020, and October 1, 2020. Main outcome measures included feasibility (patient recruitment and handheld OCT success rates) and repeatability, which were assessed using intraclass correlation coefficients (ICCs) where repeated images of the optic nerve head (ONH) within the same visit were available. ONH parameters used for repeatability analysis included cup depth, width, and area; disc width; rim height; retinal thickness; retinal nerve fiber layer thickness; and Bruch's membrane opening minimum rim width.

Results: Fifty children were approached, and all 50 (100%) were successfully recruited. Median age was 51.1 months (range, 1.9-156.9; interquartile range, 37.0-74.2), and 33 of the children (66%) were male. At least one ONH image was obtained in 43 children (86%), and bilateral ONH imaging was successful in 38 children (76%). Factors boosting the likelihood of success included good understanding and cooperation of the child and parent/guardian and availability of an assistant. Repeatability analysis was performed in 20 children, demonstrating good repeatability (ICC range, 0.77-0.99; the majority exceeded 0.90). OCT correctly identified two cases of intracranial hypertension, one of which was undetected by prior fundoscopy.

Conclusions: Handheld OCT is feasible and repeatable in children with syndromic and non-syndromic forms of craniosynostosis.

Translational Relevance: Our handheld OCT approach could be used for the clinical surveillance of children with craniosynostosis.
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http://dx.doi.org/10.1167/tvst.10.8.24DOI Listing
July 2021

Sex, gender, and retinoblastoma: analysis of 4351 patients from 153 countries.

Eye (Lond) 2021 Jul 16. Epub 2021 Jul 16.

International Centre for Eye Helath, London School of Hygiene & Tropical Medicine, London, UK.

Objective: To investigate in a large global sample of patients with retinoblastoma whether sex predilection exists for this childhood eye cancer.

Methods: A cross-sectional analysis including 4351 treatment-naive retinoblastoma patients from 153 countries who presented to 278 treatment centers across the world in 2017. The sex ratio (male/female) in the sample was compared to the sex ratio at birth by means of a two-sided proportions test at global level, country economic grouping, continent, and for selected countries.

Results: For the entire sample, the mean retinoblastoma sex ratio, 1.20, was higher than the weighted global sex ratio at birth, 1.07 (p < 0.001). Analysis at economic grouping, continent, and country-level demonstrated differences in the sex ratio in the sample compared to the ratio at birth in lower-middle-income countries (n = 1940), 1.23 vs. 1.07 (p = 0.019); Asia (n = 2276), 1.28 vs. 1.06 (p < 0.001); and India (n = 558), 1.52 vs. 1.11 (p = 0.008). Sensitivity analysis, excluding data from India, showed that differences remained significant for the remaining sample (χ = 6.925, corrected p = 0.025) and for Asia (χ = 5.084, corrected p = 0.036). Excluding data from Asia, differences for the remaining sample were nonsignificant (χ = 2.205, p = 0.14).

Conclusions: No proof of sex predilection in retinoblastoma was found in the present study, which is estimated to include over half of new retinoblastoma patients worldwide in 2017. A high male to female ratio in Asian countries, India in specific, which may have had an impact on global-level analysis, is likely due to gender discrimination in access to care in these countries, rather than a biological difference between sexes.
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http://dx.doi.org/10.1038/s41433-021-01675-yDOI Listing
July 2021

Visual outcomes in children with syndromic craniosynostosis: a review of 165 cases.

Eye (Lond) 2021 May 10. Epub 2021 May 10.

Clinical and Academic Department of Ophthalmology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom.

Objective: To determine visual outcomes and prevalence of amblyogenic risk factors in children with Apert, Crouzon, Pfeiffer and Saethre-Chotzen syndromes.

Methods: We conducted a single-centre, retrospective chart review of patients assessed at our unit between October 2000 and May 2017. Our outcome measures were as follows: age at first and last examination, refraction, horizontal ocular alignment, alphabet pattern deviations, anterior segment appearance, fundus examination findings, visual evoked potentials (VEPs) and genetics. The study's primary endpoint was the proportion of children achieving best-corrected visual acuity (BCVA) ≥ 6/12 in the better eye at final visit, as per UK driving standards.

Results: 165 patients were included in this study. Breakdown of diagnoses was as follows: Crouzon (n = 60), Apert (n = 57), Pfeiffer (n = 14) and Saethre-Chotzen (n = 34). 98 patients were male. Of 133 patients with full BCVA data available, 76.7% achieved BCVA ≥ 6/12 in the better eye. Of 122 patients, anisometropia >1.00 dioptre sphere (DS) affected 18.9% and astigmatism ≥1.00DS in at least one eye affected 67.2%. Of 246 eyes, 48.4% had oblique astigmatism. Of 165 patients, 60 had exotropia and 12 had esotropia. 48 of 99 patients demonstrated 'V' pattern. On multivariable logistic regression, nystagmus (p = 0.009) and ON involvement (p = 0.001) were associated with decreased vision in the worse eye. Normal VEPs were associated with better BCVA (p = 0.036).

Conclusion: There was a high prevalence of amblyogenic factors, however, the majority achieved BCVA ≥ 6/12 in their better eye. Optic neuropathy and nystagmus had the most significant impact on vision. VEPs can help the in overall assessment of visual function.
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http://dx.doi.org/10.1038/s41433-021-01458-5DOI Listing
May 2021

Lag Time between Onset of First Symptom and Treatment of Retinoblastoma: An International Collaborative Study of 692 Patients from 10 Countries.

Cancers (Basel) 2021 Apr 19;13(8). Epub 2021 Apr 19.

Department of Ophthalmology, University of Washington, Seattle, WA 98195, USA.

Background: The relationship between lag time and outcomes in retinoblastoma (RB) is unclear. In this study, we aimed to study the effect of lag time between onset of symptoms and diagnosis of retinoblastoma (RB) in countries based on their national-income and analyse its effect on the outcomes.

Methods: We performed a prospective study of 692 patients from 11 RB centres in 10 countries from 1 January 2019 to 31 December 2019.

Results: The following factors were significantly different among different countries based on national-income level: age at diagnosis of RB ( = 0.001), distance from home to nearest primary healthcare centre ( = 0.03) and mean lag time between detection of first symptom to visit to RB treatment centre ( = 0.0007). After adjusting for country income, increased lag time between onset of symptoms and diagnosis of RB was associated with higher chances of an advanced tumour at presentation ( < 0.001), higher chances of high-risk histopathology features ( = 0.003), regional lymph node metastasis ( < 0.001), systemic metastasis ( < 0.001) and death ( < 0.001).

Conclusions: There is a significant difference in the lag time between onset of signs and symptoms and referral to an RB treatment centre among countries based on national income resulting in significant differences in the presenting features and clinical outcomes.
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http://dx.doi.org/10.3390/cancers13081956DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8073369PMC
April 2021

Pattern of comorbidities in school-aged children with cerebral palsy in Cross River State, Nigeria.

BMC Pediatr 2021 04 8;21(1):165. Epub 2021 Apr 8.

London School of Hygiene & Tropical Medicine, International Centre for Eye Health, London, UK.

Background: To describe the pattern of comorbidities in school-aged children with cerebral palsy (CP) and to identify which, if any, were associated with poor school attendance. A cross-sectional study, using the key informant methodology, between December 2017 and July 2018 was conducted in Cross River State, Nigeria. Assessments, confirmation of CP and identification of systemic comorbidities using standard tools and questionnaires were performed. Children confirmed to have CP between the ages 4 to 15 years were included.

Results: Three hundred and eighty-eight children were confirmed to have CP, 59% males. The mean age was 9.2 years ± SD 4.0; 28% were non-ambulatory (gross motor function classification system (GMFCS) level IV-V) and spastic CP was seen in 70%. Comorbidities included Speech impairment 85%, feeding difficulties 86%, and swallowing difficulties 77%, learning difficulties 88%, abnormal behaviour 62%, visual acuity impairment 54%, objective perceptual visual disorders 46%, communication difficulties 45%, epilepsy 35%, hearing impairment 12% and malnutrition 51%. Learning difficulties (OR 10.1, p < 0.001; CI: 3.6-28.1), visual acuity impairment (OR 2.8, p = 0.002; CI: 1.5-5.3), epilepsy (OR 2.3, p = 0.009; CI:1.2-4.3) manual ability classification scale 4-5 (OR 4.7,p = 0.049; CI:1.0-22.2) and CP severity (GMFCS V-VI) OR 6.9 p = 0.002, CI: 2.0-24.0.) were seen as increasing the likelihood of poor school attendance.

Conclusion: Comorbidities were common, and some were associated with limited school attendance. A multidisciplinary tailored approach to care, with application of available therapeutic interventions for comorbidities is suggested. This may be useful in reducing barriers to school attendance.
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http://dx.doi.org/10.1186/s12887-021-02637-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8028192PMC
April 2021

Incidence of Retinoblastoma Has Increased: Results from 40 European Countries.

Ophthalmology 2021 Jan 26. Epub 2021 Jan 26.

International Centre for Eye Health, London School of Hygiene & Tropical Medicine, London, United Kingdom; Goldschleger Eye Institute, Sheba Medical Center, Tel Hashomer, Tel-Aviv University, Tel-Aviv, Israel.

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http://dx.doi.org/10.1016/j.ophtha.2021.01.024DOI Listing
January 2021

Visual impairment and perceptual visual disorders in children with cerebral palsy in Nigeria.

Br J Ophthalmol 2020 Dec 2. Epub 2020 Dec 2.

International Centre for Eye Health, London School of Hygiene and Tropical Medicine Faculty of Infectious and Tropical Diseases, London, London, UK.

Cerebral palsy (CP) is the most common cause of childhood physical disability globally. This study describes the spectrum of ocular morbidity and visual impairment in a community-based (recruited by key informants) sample of children with CP in Cross River State, Nigeria.

Methods: A paediatric neurologist clinically confirmed CP and assessed systemic comorbidity. Ophthalmological assessment included developmental age appropriate acuity tests, objective refraction and objective and subjective tests of perceptual visual dysfunction (PVD).

Results: 388 children aged 4-15 years with CP were identified. Visual problems were reported by carers in only 55 (14%) cases. Binocular visual acuity impairment was seen in 20/201 by Lea symbols test (10%) and 213/388 (55%) by the mirror test. Abnormal visual fields were seen in 58/388 (14.9%); strabismus in 183 (47%) abnormal contrast sensitivity in 178 (46%) and abnormal saccades in 84 (22%), spherical refractive errors in 223 (58%), significant astigmatism in 36 (12%), accommodative dysfunction in 41 (10.6%), optic atrophy in 198 (51%). Perceptual visual disorders were present in 22 (6%) subjectively and 177 (46%) objectively. The estimated frequency of cerebral visual impairment (CVI) in children ranged from 61 (16%) to 191 (49%) if children with optic atrophy were included.

Conclusion: Children with CP have a wide spectrum of ocular morbidity and visual impairment, underestimated by carers. Children with CP require visual acuity assessments with a range of tests which account for associated comorbidities and oculomotor dysfunction. Functional vision assessments for PVD is important. CVI is common.
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http://dx.doi.org/10.1136/bjophthalmol-2020-317768DOI Listing
December 2020

Visual function subtyping in children with early-onset cerebral visual impairment.

Dev Med Child Neurol 2021 Mar 27;63(3):303-312. Epub 2020 Oct 27.

UCL Great Ormond Street Institute of Child Health, University College London, London, UK.

Aim: To develop a data-driven subgrouping method to identify and profile subtypes of early-onset childhood cerebral visual impairment (CVI).

Method: Sixty-three children with suspected or diagnosed congenital CVI were recruited (28 males, 35 females, median age=8y, range=5-16y). Cognitive, basic, and higher-order vision functions were assessed and quality of life, functional vision questionnaire, neurodevelopmental, and ophthalmological data were collected. Cluster analysis and other statistical analyses were undertaken to determine and validate the subgrouping.

Results: Forty-three participants completing the full test battery were included in cluster analysis, revealing two subgroups. Group A1 (n=15) showed selective visual perception and visuomotor deficits. Group A2 (n=28) showed more severe and broader visual perception and visuomotor deficits, and variable visual acuity. A third, lower-functioning group, Group B (n=20), was differentiated and showed significant visual acuity reduction compared with Group A (p<0.001, V=0.69). External validation showed significant cooccurring ophthalmological (e.g. strabismus p<0.001, V=0.59) and motor impairment differences (χ =16.26, p<0.001, V=0.51) between the three groups. All groups had lowered parent-reported quality of life and everyday functional vision.

Interpretation: Statistical analyses revealed three subgroups with differentiated vision function characteristics on a gradient of severity. The subgrouping method provides the first steps in developing a novel classification system to underpin future clinical diagnostics and profiling of early-onset CVI.

What This Paper Adds: Three data-driven subgroups of vision function deficits were identified. A similar severity gradient was shown in cooccurring cognitive and neurodevelopmental deficits. Reported quality of life and functional vision difficulties were low across all groups.
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http://dx.doi.org/10.1111/dmcn.14710DOI Listing
March 2021

International travel to obtain medical treatment for primary retinoblastoma: A global cohort study.

Int J Cancer 2021 04 31;148(8):1858-1866. Epub 2020 Oct 31.

International Centre for Eye Health, London School of Hygiene and Tropical Medicine, London, UK.

Early diagnosis and treatment of retinoblastoma (Rb), the most common intraocular malignancy, can save both the child's life and vision. However, access to services and hence chances for survival and preserving the eye and its vision vary widely across the globe. Some families have to, or make a choice to, leave their home country to seek planned medical treatment abroad. We aimed to investigate how frequently this cross-border travel occurs and the factors associated with it. A total of 278 Rb centres in 153 countries were recruited to participate in a global cross-sectional analysis of newly diagnosed Rb patients in 2017. Number and proportions of children who travelled from their home country for treatment were analysed by country, continent, socioeconomic stratum and clinical and demographic features. The cohort included 4351 new patients of whom 223 [5.1%, 95% confidence interval 4.5-5.8] were taken across country borders for planned medical treatment. Independently significant predictors of travelling across borders included: being from a country with a smaller population, being from a country classified as low socioeconomic status, having bilateral Rb and having intraocular disease without extraocular spread. The factors that determine international travel for Rb treatment are complex and deserve further investigation. We may need to rethink the way services are delivered in the light of the threat of severe curtailment of international travel from pandemics like corona virus disease 2019.
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http://dx.doi.org/10.1002/ijc.33350DOI Listing
April 2021

Travel burden and clinical presentation of retinoblastoma: analysis of 1024 patients from 43 African countries and 518 patients from 40 European countries.

Br J Ophthalmol 2020 Sep 15. Epub 2020 Sep 15.

Pediatric Oncology Unit, Hospital Universitario y Politécnico La Fe, Valencia, Spain.

Background: The travel distance from home to a treatment centre, which may impact the stage at diagnosis, has not been investigated for retinoblastoma, the most common childhood eye cancer. We aimed to investigate the travel burden and its impact on clinical presentation in a large sample of patients with retinoblastoma from Africa and Europe.

Methods: A cross-sectional analysis including 518 treatment-naïve patients with retinoblastoma residing in 40 European countries and 1024 treatment-naïve patients with retinoblastoma residing in 43 African countries.

Results: Capture rate was 42.2% of expected patients from Africa and 108.8% from Europe. African patients were older (95% CI -12.4 to -5.4, p<0.001), had fewer cases of familial retinoblastoma (95% CI 2.0 to 5.3, p<0.001) and presented with more advanced disease (95% CI 6.0 to 9.8, p<0.001); 43.4% and 15.4% of Africans had extraocular retinoblastoma and distant metastasis at the time of diagnosis, respectively, compared to 2.9% and 1.0% of the Europeans. To reach a retinoblastoma centre, European patients travelled 421.8 km compared to Africans who travelled 185.7 km (p<0.001). On regression analysis, lower-national income level, African residence and older age (p<0.001), but not travel distance (p=0.19), were risk factors for advanced disease.

Conclusions: Fewer than half the expected number of patients with retinoblastoma presented to African referral centres in 2017, suggesting poor awareness or other barriers to access. Despite the relatively shorter distance travelled by African patients, they presented with later-stage disease. Health education about retinoblastoma is needed for carers and health workers in Africa in order to increase capture rate and promote early referral.
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http://dx.doi.org/10.1136/bjophthalmol-2020-316613DOI Listing
September 2020

Clinical use of the Insight Inventory in cerebral visual impairment and the effectiveness of tailored habilitational strategies.

Dev Med Child Neurol 2020 11 8;62(11):1324-1330. Epub 2020 Aug 8.

UCL Great Ormond Street Institute of Child Health, University College London, London, UK.

Aim: To investigate the utility of the Insight Inventory (a structured clinical inventory completed by caregivers) for assessment of children with cerebral visual impairment; and to investigate effectiveness of tailored habilitational strategies derived from the responses to the Insight Inventory.

Method: Fifty-one eligible children (26 males, 25 females; mean age 9y 5mo, SD 3y, range 5-16y) were recruited from Great Ormond Street Hospital, London. They underwent baseline assessment including neuro-ophthalmological and neuropsychological evaluations, and parent- and child-reported ratings on a questionnaire-based measure of quality of life. Parents also completed the Insight Inventory. On the basis of responses to the Inventory, families received individualized habilitational strategies. Follow-up assessments 6 months later included repeating the Insight Inventory and quality of life questionnaires.

Results: Correlations were found between the Insight Inventory and the Wechsler Intelligence Scale for Children, Fourth Edition, the Beery-Buktenica Test of Visual-Motor Integration, and the Benton Facial Recognition Test, suggesting that the Insight Inventory is an effective tool to estimate visual-perceptual difficulties. At 6 months follow-up, caregiver reports indicated significant improvements in the quality of life of children below the age of 12 years.

Interpretation: The Insight Inventory is a simple questionnaire which covers practical aspects of cognitive visual function in everyday life. It provides in-depth information about the aspects that children struggle with. It can also guide programmes of individualized habilitation strategies, which may enhance the quality of life of younger children.

What This Paper Adds: Questionnaire scores demonstrate biologically plausible correlations with formal neuropsychological tests of visual function. After administration of matched practical habilitational strategies, younger children showed improvement in quality of life and functional vision scores.
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http://dx.doi.org/10.1111/dmcn.14650DOI Listing
November 2020

Red reflex examination in reproductive and child health clinics for early detection of paediatric cataract and ocular media disorders: cross-sectional diagnostic accuracy and feasibility studies from Kilimanjaro, Tanzania.

Eye (Lond) 2021 May 16;35(5):1347-1353. Epub 2020 Jun 16.

International Centre for Eye Health, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK.

Background/objectives: Late presentation of congenital cataract in the developing world has led to poor outcomes such that cataract is the leading cause of childhood blindness. Our hypothesis was that, sensitivity of red-reflex testing is greater than sensitivity of torchlight examination. We aimed to compare sensitivity of new red reflex screening tools and assess the feasibility of Arclight red reflex screening in the community.

Subject/methods: We compared the diagnostic accuracy of four different screening tools for cataract and retinoblastoma performed by ophthalmic nurses, using a clinic based enriched sample of 41 positives and 60 negatives. We then conducted a separate feasibility study, training non-specialist community nurses. Following the training, community nurses examined 2827 children <5 years with Arclight who were attending their clinics for growth monitoring and immunisation.

Findings: Diagnostic accuracy study: estimated sensitivities were 97.6% for Catcam, 92.7% for Arclight, 90.2% for PEEK retina and 7.3% for torchlight. Estimated specificities were above 90% for Catcam, Arclight and torchlight and 87% for PEEK retina. Feasibility study: twenty-four out of 2728 children screened failed community screening, seven were true positive (six cataract, one retinoblastoma). Prevalence of bilateral cataract was 1.5/1000 (95% CI: 0.40-3.75 per 1000).

Conclusions: Arclight and CatCam have higher sensitivity than torchlight, are easy to learn and use by primary health care nurses. Red reflex testing should be recommended in the WHO guidelines instead of torchlight examination to help early detection of potential blinding causes including congenital cataract and retinoblastoma.
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http://dx.doi.org/10.1038/s41433-020-1019-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8182787PMC
May 2021

Presentation, surgery and 1-year outcomes of childhood cataract surgery in Tanzania.

Br J Ophthalmol 2021 03 10;105(3):334-340. Epub 2020 Jun 10.

Clinical Research, London School of Hygiene and Tropical Medicine, London, UK.

Background: Recent reports have suggested a significant change in the causes of blindness in children in low-income countries cataract becoming the leading cause. We aimed to investigate the presentations and surgical outcomes in children with cataract operated at different ages in Tanzania.

Methods: We conducted a prospective study of 228 children aged ≤192 months at three tertiary centres, 177 with bilateral cataracts and prospectively followed them for 1-year postsurgery. We collected demographic, surgical, preoperative and postoperative clinical characteristics using the standard childhood cataract surgical assessment questionnaire. Families were encouraged to return for follow-up by phone with travel reimbursement where necessary.

Results: Preoperatively, 76% bilateral children were blind in the better eye. 86% of children were followed up at 1 year and 54% bilateral children achieved visual acuity of 0.48 logMAR or better in the better eye and 5% were blind. 33% of unilateral children achieved visual acuity of 0.48 logMAR or better and 17% were blind. Preoperative blindness (adjusted OR (AOR) 14.65; 95% CI 2.21 to 97.20), preoperative nystagmus/strabismus (AOR 9.22; 95% CI 2.66 to 31.97) and aphakia (AOR, 5.32; 95% CI 1.05 to 26.97) predicted poor visual outcome in bilateral cases. 9% of 342 refracted eyes had initial postoperative cylinder of 1.5 D or more, as did a similar proportion (11%) of 315 eyes refracted 1 year after surgery. Acute fibrinous uveitis occurred in 41 (12%) eyes.

Conclusion: Three-quarters of children were blind preoperatively whereas over half had good vision 1-year postoperatively. Preoperative blindness, nystagmus/strabismus and aphakia predicted poor visual outcome, suggesting that cataract density determines density of amblyopia.
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http://dx.doi.org/10.1136/bjophthalmol-2020-316042DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7907562PMC
March 2021

Robotic microscopy for everyone: the OpenFlexure microscope.

Biomed Opt Express 2020 May 8;11(5):2447-2460. Epub 2020 Apr 8.

Centre for Photonics and Photonic Materials, Department of Physics, University of Bath, UK.

Optical microscopes are an essential tool for both the detection of disease in clinics, and for scientific analysis. However, in much of the world access to high-performance microscopy is limited by both the upfront cost and maintenance cost of the equipment. Here we present an open-source, 3D-printed, and fully-automated laboratory microscope, with motorised sample positioning and focus control. The microscope is highly customisable, with a number of options readily available including trans- and epi- illumination, polarisation contrast imaging, and epi-florescence imaging. The OpenFlexure microscope has been designed to enable low-volume manufacturing and maintenance by local personnel, vastly increasing accessibility. We have produced over 100 microscopes in Tanzania and Kenya for educational, scientific, and clinical applications, demonstrating that local manufacturing can be a viable alternative to international supply chains that can often be costly, slow, and unreliable.
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http://dx.doi.org/10.1364/BOE.385729DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7249832PMC
May 2020

Referral patterns of children with glaucoma and their caretakers in Northern Tanzania.

Int J Ophthalmol 2020 18;13(3):452-457. Epub 2020 Mar 18.

International Centre for Eye Health, Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK.

Aim: To describe the referral patterns of children with primary childhood glaucoma (PCG) or secondary childhood glaucoma (SCG) and their presenting symptoms in Northern Tanzania.

Methods: A retrospective observational study of children <17y with PCG or SCG who were referred to Kilimanjaro Christian Medical Centre (KCMC) Eye Department between 2000 and 2013 was conducted. Presenting symptoms, age at presentation, place of origin, distance to hospital, type of glaucoma, visual acuity, optic disc appearance (vertical cup-to-disc ratio) and type of referral were described.

Results: Seventy patients with PCG and 27 patients with SCG were included in the study. Median age at first presentation was 1y in the PCG group (range 0-16y) and 9y in the SCG group (range 1-15y). In both groups around 87% of the children presented already with low vision (logMAR>0.48, better eye). Most of the children (60%) and their caretakers presented on their own initiative, while 24% were sent by different general health cadres and 16% by eye care professionals. Buphthalmos was the main symptom mentioned as a trigger for presentation.

Conclusion: The study shows that most of the children presented late resulting in advanced stages of glaucoma at the time of initiation of treatment. The majority attended the referral eye department on their own initiative with buphthalmos being the most commonly described symptom. Awareness creation among caretakers of children, general health and eye care providers, ideally embedded in general child health promotion activities, is needed to increase and accelerate referrals.
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http://dx.doi.org/10.18240/ijo.2020.03.13DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7154200PMC
March 2020

Nanometer control in plasmonic systems through discrete layer-by-layer macrocycle-cation deposition.

Nanoscale 2020 Apr;12(16):8706-8710

Melville Laboratory for Polymer Synthesis, Department of Chemistry, University of Cambridge, CB2 1EW, UK.

In this work, we demonstrate that coordination interactions between Fe3+ and cucurbit[7]uril (CB[7]) can be utilised to build up defined nanoscale spacing layers in metallic nanosystems. We begin by characterising the layer-by-layer deposition of CB[7] and FeCl3·6H2O coordination layers through the use of a Quartz-Crystal Microbalance (QCM) and contact angle measurements. We then apply this layered structure to accurately control the spacing, and thus optical properties, of gold nanoparticles in a Nanoparticle-on-Mirror (NPoM) structure, which is demonstrated via normalising plasmon resonance spectroscopy.
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http://dx.doi.org/10.1039/d0nr00902dDOI Listing
April 2020

The OpenFlexure Block Stage: sub-100 nm fibre alignment with a monolithic plastic flexure stage.

Opt Express 2020 Feb;28(4):4763-4772

As 3D printers become more widely available, researchers are able to rapidly produce components that may have previously taken weeks to have machined. The resulting plastic components, having high surface roughness, are often not suitable for high-precision optomechanics. However, by playing to the strengths of 3D printing-namely the ability to print complex internal geometries-it is possible to design monolithic mechanisms that do not rely on tight integration of high-precision parts. Here we present a motorised monolithic 3D-printed plastic flexure stage with sub-100 nm resolution that can perform automated optical fibre alignment.
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http://dx.doi.org/10.1364/OE.384207DOI Listing
February 2020

Global Retinoblastoma Presentation and Analysis by National Income Level.

JAMA Oncol 2020 05;6(5):685-695

Imam Hussein Cancer Center, Karbala, Iraq.

Importance: Early diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale.

Objectives: To report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis.

Design, Setting, And Participants: A total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017.

Main Outcomes And Measures: Age at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis.

Results: The cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4%) were female. Most patients (n = 3685 [84.7%]) were from low- and middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n = 2638 [62.8%]), followed by strabismus (n = 429 [10.2%]) and proptosis (n = 309 [7.4%]). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5%) patients having intraocular retinoblastoma and 2 (0.3%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1%) having extraocular retinoblastoma and 94 of 498 (18.9%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 [95% CI, 12.94-24.80], and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 [95% CI, 4.30-7.68]).

Conclusions And Relevance: This study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs.
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http://dx.doi.org/10.1001/jamaoncol.2019.6716DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7047856PMC
May 2020

Clinical features and aetiology of cerebral palsy in children from Cross River State, Nigeria.

Arch Dis Child 2020 07 20;105(7):625-630. Epub 2020 Jan 20.

International Centre for Eye Health, London School of Hygiene and Tropical Medicine, London, United Kingdom.

Objective: There are few studies on cerebral palsy (CP) in African children and our study aimed to describe the aetiology, characteristics and severity of CP in children from Nigeria.

Design: A population-based study using key informant methodology (KIM) was conducted as part of a clinical research trial. Children aged 4-15 years were clinically assessed for CP.

Results: The estimated prevalence of CP using KIM was 2.3/1000 children (95% CI 2.0 to 2.5/1000). 388 children were diagnosed with CP, with Gross Motor Function Classification System level 1 in 70 (18.1%), II in 156 (40.2%), III in 54 (13.9%), IV in 54 (13.9%), V in 54 (13.9%). 300/388 (77.3%) had Manual Ability Classification Scale of level 1-3 and 88 (22.7%) of level 4-5. CP types were spastic in 271 (70%), with 60% of these bilateral and 40% unilateral, ataxic 38 (9.8%), dystonic 18 (4.6%), choreoathetoid 29 (7.5%) and unclassifiable 32 (8.3%). Postneonatal risk factors for CP were seen in 140 (36.1%) children including malaria with seizures 101/140 (72.1%), malaria with coma 21/140 (15.0%), meningitis 12/140 (8.6%), tuberculosis 2/140 (1.4%), sickle cell disease 3/140 (2.2%), HIV 1/221 (0.7%). Prenatal/perinatal risk factors were seen in 248 (63.9%%), birth asphyxia 118 (47.6%) and clinical congenital rubella syndrome 8 (3.3%) and hyperbilirubinaemia 59 (23.8%) were identified as preventable risk factors for CP.

Conclusion: The profile of CP in this population is similar to that found in other low-income and middle-income countries (LMIC). Some risk factors identified were preventable. Prevention and management strategies for CP designed for LMIC are needed.
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http://dx.doi.org/10.1136/archdischild-2019-317932DOI Listing
July 2020

Akirin Is Required for Muscle Function and Acts Through the TGF-β Sma/Mab Signaling Pathway in Development.

G3 (Bethesda) 2020 01 7;10(1):387-400. Epub 2020 Jan 7.

Department of Biology University of Iowa, Iowa City, IA 52240 and

Akirin, a conserved metazoan protein, functions in muscle development in flies and mice. However, this was only tested in the rodent and fly model systems. Akirin was shown to act with chromatin remodeling complexes in transcription and was established as a downstream target of the NFκB pathway. Here we show a role for Akirin/AKIR-1 in the muscle and body length regulation through a different pathway. Akirin localizes to somatic tissues throughout the body of , including muscle nuclei. In agreement with its role in other model systems, Akirin loss of function mutants exhibit defects in muscle development in the embryo, as well as defects in movement and maintenance of muscle integrity in the adult. We also have determined that Akirin acts downstream of the TGF-β Sma/Mab signaling pathway in controlling body size. Moreover, we found that the loss of Akirin resulted in an increase in autophagy markers, similar to mutants in the TGF-β Sma/Mab signaling pathway. In contrast to what is known in rodent and fly models, Akirin does not act with the SWI/SNF chromatin-remodeling complex, and is instead involved with the NuRD chromatin remodeling complex in both movement and regulation of body size. Our studies define a novel developmental role (body size) and a new pathway (TGF-β Sma/Mab) for Akirin function, and confirmed its evolutionarily conserved function in muscle development in a new organism.
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http://dx.doi.org/10.1534/g3.119.400377DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6945016PMC
January 2020

The effect of visual support strategies on the quality of life of children with cerebral palsy and cerebral visual impairment/perceptual visual dysfunction in Nigeria: study protocol for a randomized controlled trial.

Trials 2019 Jul 10;20(1):417. Epub 2019 Jul 10.

London School of Hygiene and Tropical Medicine, International Centre for Eye Health, London, WC1E 7HT, UK.

Background: Cerebral visual impairment (CVI), including perceptual visual dysfunction (PVD), is common in children with cerebral palsy (CP). Inventories of questions relating to practical aspects of visual perception in everyday life, in particular the closed-ended Insight Questions Inventory (IQI), can be used to assess CVI/PVD. Studies linking responses to the inventory with specific visual support strategies, aimed at modifying the child's environment and/or behaviour to minimize the impact of the CVI/PVD, have been piloted. The IQI and tailored strategies have not been used in an African population, nor have they been tested in a controlled trial. This trial will compare the effectiveness of the IQI and linked visual support strategies versus general supportive treatments on the quality of life of children with CVI/PVD and CP through a randomized controlled trial.

Methods/design: This is a prospective, double-blind, parallel-arm, randomized controlled trial. The primary outcome is change in quality of life scores between the two arms of the trial at 6 weeks, assessed using the Paediatric Quality of Life Inventory (PedsQL) generic 4.0 and CP 3.0 module. All children will undergo baseline assessment including the Open Questions Inventory, IQI, PedsQL 3.0, PedsQL 4.0 generic, and the Strengths and Difficulties Questionnaire (SDQ). Eligible children with CP aged 4 years to < 16 years will be stratified and blocked by the age groups 4-9 and 10 to < 16 years and by Gross Motor Function Classification System (GMFCS) levels 1-3 and 4-5. Families in the intervention arm will receive tailored insight visual support strategies and telephone calls during the 6-week trial period. The control arm will receive standard treatment and the intervention after the 6-week trial period. Follow-up interviews will be performed in both arms at 6 weeks with a repeat administration of the PedsQL CP 4.0 and 3.0, the IQI and the SDQ. Secondary outcomes include a change in functional vision.

Discussion: This randomized controlled trial will provide evidence of the effectiveness of this intervention for children with CP in a resource-poor setting.

Trial Registration: Pan African Clinical Trials Registration, PACTR201612001886396 . Registered on 3 December 2016.
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http://dx.doi.org/10.1186/s13063-019-3527-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6617659PMC
July 2019

Long-range depth imaging using a single-photon detector array and non-local data fusion.

Sci Rep 2019 May 30;9(1):8075. Epub 2019 May 30.

School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK.

The ability to measure and record high-resolution depth images at long stand-off distances is important for a wide range of applications, including connected and automotive vehicles, defense and security, and agriculture and mining. In LIDAR (light detection and ranging) applications, single-photon sensitive detection is an emerging approach, offering high sensitivity to light and picosecond temporal resolution, and consequently excellent surface-to-surface resolution. The use of large format CMOS (complementary metal-oxide semiconductor) single-photon detector arrays provides high spatial resolution and allows the timing information to be acquired simultaneously across many pixels. In this work, we combine state-of-the-art single-photon detector array technology with non-local data fusion to generate high resolution three-dimensional depth information of long-range targets. The system is based on a visible pulsed illumination system at a wavelength of 670 nm and a 240 × 320 array sensor, achieving sub-centimeter precision in all three spatial dimensions at a distance of 150 meters. The non-local data fusion combines information from an optical image with sparse sampling of the single-photon array data, providing accurate depth information at low signature regions of the target.
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http://dx.doi.org/10.1038/s41598-019-44316-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6542841PMC
May 2019

Syndromic Craniosynostosis: Complexities of Clinical Care.

Mol Syndromol 2019 Feb 16;10(1-2):83-97. Epub 2019 Jan 16.

Great Ormond Street Craniofacial Unit, UCL Great Ormond Street Institute of Child Health, Great Ormond Street Hospital for Children NHS Trust, London, UK.

Patients with syndromic craniosynostosis have a molecularly identified genetic cause for the premature closure of their cranial sutures and associated facial and extra-cranial features. Their clinical complexity demands comprehensive management by an extensive multidisciplinary team. This review aims to marry genotypic and phenotypic knowledge with clinical presentation and management of the craniofacial syndromes presenting most frequently to the craniofacial unit at Great Ormond Street Hospital for Children NHS Foundation Trust.
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http://dx.doi.org/10.1159/000495739DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6422147PMC
February 2019

Testing the red reflex.

Community Eye Health 2019 17;32(107):54. Epub 2019 Dec 17.

Professor of International Eye Health; London School of Hygiene and Tropical Medicine, London, UK.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7041824PMC
December 2019

Tips for assessing vision in a baby or child.

Authors:
Richard Bowman

Community Eye Health 2019 17;32(107):52-53. Epub 2019 Dec 17.

Honorary Clinical Consultant: International Centre for Eye Health, London School of Hygiene and Tropical Medicine, London, UK.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7041836PMC
December 2019

A Novel Role for α-Importins and Akirin in Establishment of Meiotic Sister Chromatid Cohesion in .

Genetics 2019 02 18;211(2):617-635. Epub 2018 Dec 18.

Department of Biology, University of Iowa, Iowa City, Iowa 52240

During meiotic prophase I, sister chromatid cohesion is established in a way that supports the assembly of the synaptonemal complex (SC). The SC connects homologous chromosomes, directing meiotic recombination to create crossovers. In this paper, we identify two proteins that cooperate to import and load meiotic cohesins, thus indirectly promoting SC assembly. AKIR-1 is a protein with a previously identified meiotic role in SC disassembly. mutants have no obvious defects in sister chromatid cohesion. We identified , a gene encoding for an α-importin nuclear transport protein, as a gene interacting with Analysis of double mutants reveals a decrease in the number of germline nuclei and the formation of polycomplexes (PCs) (an SC protein aggregate). These PCs contain proteins that are part of the two main substructures of the SC: the central region and the lateral element. Unlike typical PCs, they also contain sister chromatid cohesion proteins. In double mutants, PCs are located in both the nucleus and the cytoplasm. This suggests that the defects observed in the double mutants are both in nuclear import and in the assembly of sister chromatid cohesion. PC formation is also associated with recombination defects leading to reduced numbers of crossovers. Similarly to cohesion mutants, the pairing center protein HIM-8 is mislocalized in double mutants, forming multiple foci. We propose that AKIR-1 and IMA-2 operate in parallel pathways to import and load chromosomally associated cohesin complex proteins in meiotic nuclei, a novel finding for both of these conserved proteins.
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http://dx.doi.org/10.1534/genetics.118.301458DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6366927PMC
February 2019

Testing the red reflex.

Community Eye Health 2018 ;31(101):23

Professor of International Eye Health; London School of Hygiene and Tropical Medicine, London, UK.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5998403PMC
January 2018
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