Childhood visual impairment in England: a rising trend

Sight impairment registration in Trinidad: trend in causes and population coverage in comparison to the National Eye Survey of Trinidad and Tobago

BACKGROUND

Little was known about the population coverage and causes of sight impairment (SI) registration within the Caribbean, or the extent to which register studies offer insights into population eye health.

METHODS

We compared causes of SI registration in the Trinidad and Tobago Blind Welfare Association (TTBWA) register with findings from the 2014 National Eye Survey of Trinidad and Tobago (NESTT), and estimated registration coverage. Cross-sectional validation studies of registered clients included interviews, visual function and cause ascertainment in July 2013, and interviews and visual function in July 2016.

RESULTS

The TTBWA register included 863 people (all ages, 48.1%(n = 415) male) registered between 1951 and 2015. The NESTT identified 1.1%(75/7158) people aged ≥5years eligible for partial or severe SI registration, of whom 49.3%(n = 37) were male. Registration coverage was approximately 7% of the eligible population of Trinidad. Nevertheless, there was close agreement in the causes of SI comparing the register and population-representative survey. Glaucoma was the leading cause in both the register (26.1%,n = 225) and population-based survey (26.1%, 18/69 adults), followed by cataract and diabetic retinopathy. In the validation studies combined, 62.6%(93/151) clients had severe SI, 28.5%(43/151) had partial SI and 9.9%(15/151) did not meet SI eligibility criteria. SI was potentially avoidable in at least 58%(n = 36/62) adults and 50%(n = 7/14) children.

CONCLUSION

We report very low register coverage of the SI population, but close agreement in causes of SI to a contemporaneous national population-based eye survey, half of which resulted from preventable or treatable eye disease.

Case report: Bilateral damage to the immature optic radiation and secondary massive loss of retinal ganglion cells causing tunnel vision

We describe the case of a 30-year-old woman, who needed a formal report on her visual impairment to seek support from society. She was born preterm, and during her neonatal period, she suffered from bilateral intraventricular hemorrhage (IVH) grade 3, a condition that can cause cerebral visual impairment (CVI) due to damage to the retro-geniculate visual pathways. Individuals with such brain damage of this severity are often restricted by cerebral palsy (CP) and intellectual disability, and thus have a limited ability to cooperate in the assessment of visual function. However, our patient was capable of providing reliable test results, and she manifested only a small island of central vision in each eye, with additional reduced visual acuities. She cooperated well in examinations involving MRI of the brain, optical coherence tomography (OCT) of retinal ganglion cells, and multi-focal visual evoked potentials, with each test providing information about potential limitations in the structural prerequisites for visual function. What distinguishes our case is the severity of the damage to the optic radiations and the massive secondary loss of most of her retinal ganglion cells (GCs). However, there is some measurable visual function, which may be due to developmental neuroplasticity during early development, when surviving GCs prioritize the central visual field. Despite her visual difficulties, she is a keen portrait painter. Our patient may be representative of, and a spokesperson for, other individuals with extensive brain damage of the same etiology, who are unable to perform perimetric tests and therefore run the risk of not being recognized as severely visually impaired, and consequently, not being given the best conditions for habilitation. OCT may serve as a helpful diagnostic tool. Aim: This study aims to describe visual behavior and practical applications of visual function in relation to structural prerequisites for visual function.

Effectiveness of early spectacle intervention on visual outcomes in babies at risk of cerebral visual impairment: a parallel group, open-label, randomised clinical feasibility trial protocol

INTRODUCTION

Hypoaccommodation is common in children born prematurely and those with hypoxic ischaemic encephalopathy (HIE), with the potential to affect wider learning. These children are also at risk of longer-term cerebral visual impairment. It is also well recognised that early intervention for childhood visual pathology is essential, because neuroplasticity progressively diminishes during early life. This study aims to establish the feasibility and acceptability of conducting a randomised controlled trial to test the effectiveness of early near vision correction with spectacles in infancy, for babies, at risk of visual dysfunction.

METHODS AND ANALYSIS

This is a parallel group, open-label, randomised controlled (feasibility) study to assess visual outcomes in children with perinatal brain injury when prescribed near vision spectacles compared with the current standard care-waiting until a problem is detected. The study hypothesis is that accommodation, and possibly other aspects of vision, may be improved by intervening earlier with near vision glasses. Eligible infants (n=75, with either HIE or <29 weeks preterm) will be recruited and randomised to one of three arms, group A (no spectacles) and two intervention groups: B1 or B2. Infants in both intervention groups will be offered glasses with +3.00 DS added to the full cycloplegic refraction and prescribed for full time wear. Group B1 will get their first visit assessment and intervention at 8 weeks corrected gestational age (B1) and B2 at 16 weeks corrected gestational age. All infants will receive a complete visual and neurodevelopmental assessment at baseline and a follow-up visit at 3 and 6 months after the first visit.

ETHICS AND DISSEMINATION

The South-Central Oxford C Research Ethics Committee has approved the study. Members of the PPI committee will give advice on dissemination of results through peer-reviewed publications, conferences and societies.

TRIAL REGISTRATION NUMBER

ISRCTN14646770, NCT05048550, NIHR ref: PB-PG-0418-20006.

Vision impairment: To register or not to register? That is the question

For patients to enjoy the benefits of vision impairment registration, they need to be certified by an ophthalmologist. There have been concerns about barriers and a lack of awareness of benefits and certification criteria among ophthalmologists leading to under-registration. The purpose of this study was to gain insight into the certification process in terms of potential barriers, clinical decision-making, and understanding of current guidelines and registration benefits.

Ophthalmologists completed a survey on understanding registration benefits and barriers for certification ( n = 22) and a survey on clinical decision-making in certification ( n = 21). Furthermore, visual function and registration data were collected at a hospital Low Vision Clinic in Edinburgh from all new referrals ( n = 89) over a 4-month period from August to November 2020. Our study showed that the main barriers for vision impairment certification were insufficient awareness of registration benefits, uncertainty of when to certify, and a lack of time in clinic. Ophthalmologists were more confident about certification of ocular versus neurological visual impairment. In terms of clinical decision-making, the ophthalmologists’ survey placed most importance on visual-field assessments, followed by visual acuity. Very little importance was placed on contrast sensitivity. Our findings suggest that ophthalmologists would benefit from more education into the benefits of registration and more guidance when registering patients with neurological conditions affecting functional vision in particular. It may be beneficial to highlight the role of contrast sensitivity during the certification process to ophthalmologists.

Retinal ganglion cell topography predicts visual field function in spastic cerebral palsy

The aim of this study was to evaluate the use of optical coherence tomography (OCT) to identify and assess visual field defects caused by primary damage to the optic radiation in individuals with spastic cerebral palsy (CP). Ten individuals with spastic CP (six females, four males, with a median age of 21 years [range 17-38y]) had their brain lesions documented with conventional magnetic resonance imaging (MRI) and diffusion-weighted MRI fibre tractography. Their macular ganglion cell layer (GCL) and inner plexiform layer (IPL) were examined with OCT and their visual fields were plotted. All participants had good visual acuity and were able to cooperate with the MRI and OCT examinations, as well as undergoing reliable perimetry. We found focal thinning of the GCL+IPL and corresponding homonymous visual field defects in individuals with brain damage affecting the optic radiation. We used GCL+IPL sector asymmetry as a sensitive OCT parameter to identify focal visual field defects. We observed no such sector asymmetry in GCL+IPL, or focal visual field defects, in individuals with normal MRI optic radiation imaging. Lesions affecting the optic radiation cause retrograde trans-synaptic degeneration of retinal ganglion cells. OCT examination of the GCL in the macula identified corresponding focal damage to the optic radiation in individuals with spastic CP and can be used to predict focal visual field defects. WHAT THIS PAPER ADDS: Spastic cerebral palsy (CP) may be associated with damage to the optic radiation. Damage to the optic radiation causes retrograde trans-synaptic degeneration (RTSD). RTSD can be mapped using optical coherence tomography. Ganglion cell topography can predict visual field defects in individuals with spastic CP.

Injuries to the Immature Optic Radiation Show Correlated Thinning of the Macular Ganglion Cell Layer

Injuries to the immature optic radiation (OR) are associated with thinning of the retinal nerve fiber layer and corresponding visual field (VF) defects. The aim of the current study was to seek evidence for causal retrograde trans-synaptic degeneration by exploring the correspondence between the localization and extension of the injury to the OR and the structure of the macular ganglion cell complex, and the relation to VF function. Seven adults (age range 18–35) with visual dysfunction secondary to white-matter damage of immaturity and six healthy adults (age range 22–33) underwent magnetic resonance imaging (MRI). Fiber tractography was used to generate the geniculate projections to the dorsal and ventral striate cortex, delineated by retinotopic functional MRI mapping. The structure of the macular ganglion cell complex was measured with optical coherence tomography. The tractography showed overlaps between the dorsal and ventral geniculo-striate projections. However, in four patients with inferior VF defects, the dorsal projections were to a large extent traversing the space normally solely occupied by ventral projections. This is consistent with structural changes to the OR and suggests of re-organization upon injury. Diffusion parameters were significantly different between patients and controls, and most pronounced in the dorsal geniculo-striate projections, with a pattern indicating primary injury. The macular ganglion cell complex was significantly thinner in the patients and most pronounced in the superior sectors; a pattern particularly evident in the four patients with inferior VF defects. The ratio of the mean thickness of the macular ganglion cell complex in the superior and inferior sectors significantly correlated with the axial and mean diffusivities in the contra- and ipsilateral dorsal striate projections. The results suggest a causal link between injuries to the superior portion of the immature OR and secondary thinning in the macular ganglion cell complex, resulting in inferior VF defects.

Impact of healthcare strategies on patterns of paediatric sight impairment in a developed population: 1984-2011

PurposeThe aim of our study was to analyse paediatric sight-impairment trends in Northern Ireland (NI) over a 28-year period to better understand the impact which changes in health-care provision may be having on childhood blindness and to enable us to assess our progress towards achieving the World Health Organisation (WHO) aims.MethodsA database of Certificates of Visual Impairment completed for NI children aged <16 years was used to determine the cause of sight impairment from 1984 to 2011. Causes were classified into preventable or treatable conditions and analysed for trends.ResultsFive hundred and ninety-eight children were registered as having impaired vision over the 28-year period. A total of 22% had preventable or treatable conditions. Optic atrophy was the most common cause responsible for 16% of registrations followed by albinism (12%), cerebral visual impairment (11%), congenital cataract (8%), retinopathy of prematurity (ROP) (8%), and congenital motor nystagmus (7%). The incident rate (per million population aged <16 years) for registerable vision loss due to congenital cataract decreased from 5.89 (CI 2.82-10.83) in 1984-1987 to 2.63 (CI 0.72-6.74) in 2008-2011. For ROP, the incident rate peaked during 2000-2003 at 8.87 (CI 4.85-14.88). Thereafter, there was a statistically significant reduction in incident rate to 1.98 (CI 0.41-5.77) in 2008-2011 (P=0.008).ConclusionsSight-impairment registrations due to preventable or treatable causes have decreased over the past 28 years. This is likely due to better surgical techniques and improved refractive care for conditions such as congenital cataract and ongoing research and treatment protocols for conditions such as ROP. Future advances in this area may help to further reduce the burden of childhood sight impairment and improve quality of life for these patients.

Is there evidence that the yearly numbers of children newly certified with sight impairment in England and Wales has increased between 1999/2000 and 2014/2015? A cross-sectional study

OBJECTIVES

To use routine data capture from hospitals in England and Wales to identify whether there has been an increase in the annual numbers of children newly certified sight impaired in England and Wales between 1999/2000 and 2014/2015 and to examine causes of certifiable sight impairment in children certified in 2014/2015.

DESIGN

A cross-sectional study including an analysis of all certificates of vision impairment completed in hospitals in England and Wales each year between 2007/2008 and 2014/2015 and all certificates completed in hospitals in England and Wales in 1999/2000.

PARTICIPANTS

Certificates for all individuals aged 16 years or less at the time of certification in England and Wales for each financial year between 1 April 2007 and the 31 March 2015 and for individuals aged 15 years or less for the year ending 31 March 2000. We obtained information on the main cause of certifiable sight loss for all children certified in 2014/2015. We estimated crude and sex specific incidence estimates with 95% confidence intervals computed by Byars method.

RESULTS

In 1999/2000, the estimated incidence (95 % CI) of certification was 8.2 (7.7 to 8.8) per 1 00 000. In 2007/2008, the estimated incidence was statistically significantly higher at 10.1 (9.5 to 10.7). Since then a trend of increasing incidence with time has been observed until 2014/2015 when an estimated incidence of 13.3 (12.6 to 14.0) was observed. Hereditary retinal dystrophies, cerebral visual impairment and nystagmus were the most common single causes of certifiable sight impairment in children in 2014/2015.

CONCLUSION

Our findings show that in England and Wales there has been an increase in the number of children newly certified sight impaired by consultant ophthalmologists since 1999/2000. This mirrors our previous findings based on data originating within social service departments.

Support for infants and young people with sight loss: a qualitative study of sight impairment certification and referral to education and social care services

OBJECTIVES

To examine the experience of infants, children and their parents, the role of ophthalmologists and other health, social care and education professionals in the certification and registration processes and examine the relationship between certification and referrals and pathways to support.

DESIGN

Qualitative study.

SETTING

Telephone interviews with health and, social care professionals, qualified teachers of children and young people with vision impairment (QTVIs) and parents of infants/children in England.

PARTICIPANTS

52 health, social care and education professionals who are part of the certification or registration process. 26 parents of infants and children with vision impairment.

RESULTS

Referrals to education do not require a Certificate of Vision Impairment (CVI); however, the majority of parents received support from education and social services only after an offer of the CVI, which was often dependent on having a formal diagnosis. Parents stated they wanted support sooner, particularly parents of children with additional complex needs who experienced longer delays. Areas with multidisciplinary teams and support roles such as eye clinic liaison officers (ECLOs) appeared to have more reliable referral pathways.

CONCLUSIONS

For infants and children with vision impairment, there should be a consistent mechanism for triggering education and social care support even with uncertainty about diagnosis and/or prognosis. All professionals involved in the certification and registration processes (ophthalmologists, optometrists, ECLOs, orthoptists, social workers, QTVIs) can better communicate the value and benefits of certification and registration.

Trends in the incidence and causes of severe visual impairment and blindness in children from Israel

PURPOSE

To describe trends in the incidence and causes of legal childhood blindness in Israel, one of the few countries worldwide that maintain a national registry of the blind.

METHODS

We performed a historical cohort study of annual reports of the National Registry of the Blind (NRB) between 1999 and 2013. All data regarding demographic information, year of registration and cause of blindness of children 0-18 years of age registered for blind certification were obtained from the annual reports of the NRB. Causes of legal blindness analyzed were optic atrophy, retinitis pigmentosa, retinopathy of prematurity (ROP), albinism, other retinal disorders, cataract, and glaucoma. The main outcome measure was the incidence of new cases of certified legal blindness.

RESULTS

The incidence of newly registered legally blind children in Israel almost halved from 7.7 per 100,000 in 1999 to 3.1 per 100,000 in 2013. The decline was mainly attributable to a decreased incidence of blindness resulting from retinitis pigmentosa and ROP. The incidence of registered cases due to cerebral visual impairment increased.

CONCLUSIONS

During the past decade the incidence of severe childhood visual impairment and blindness declined in Israel. A continuous decline in consanguineous marriages among the Jewish and Arab populations in Israel may have contributed to the decrease in the rate of vision loss due to retinitis pigmentosa in children.

Epidemiology, aetiology and management of visual impairment in children

An estimated 19 million of the world's children are visually impaired, while 1.4 million are blind. Using the UK as a model for high income countries, from a population-based incidence study, the annual cumulative incidence of severe visual impairment/blindness (SVL/BL) is estimated to be 6/10 000 by age 15 years, with the incidence being highest in the first year of life. The population of visually impaired children within high, middle and lower income countries differ considerably between and within countries. The numerous and mainly uncommon disorders which can cause impaired vision result in heterogeneous population which includes a substantial proportion (for SVI/BL, the majority) of children with additional systemic disorders or impairments whose needs differ substantially from those with isolated vision impairment. Paediatricians and other paediatric professionals have a key role in early detection and multidisciplinary management to minimise the impact of visual impairment (VI) in childhood.