Nordic registers of visually impaired children

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.

A Review of the Published Literature in Global Population-Based Studies of Childhood Blindness and Vision Impairment

PURPOSE

Reducing childhood blindness and vision impairment (BVI) remains a global health priority. Our purpose was to summarize the peer-reviewed literature to date on measuring and reporting childhood BVI using population-based surveys and vision examinations.

METHODS

We conducted a scoping review of published studies that aimed to report BVI prevalence in children or studies that aimed to report BVI prevalence in the general population but which also included children. There were 201 articles identified for abstract review, and 86 studies were included in the final review.

RESULTS

There were 52 studies (60%) that specifically aimed to investigate prevalence of blindness and/or vision impairment among child populations, while the remaining 34 studies aimed to study BVI in the general population but still reported data for age ranges that included children. The majority of researchers used the WHO criteria for blindness and vision impairment, sometimes with modifications. Age definitions for children varied considerably, with maximum cutoffs ranging from 3 to 20 years.

CONCLUSION

The available literature on childhood blindness indicates that while there has been substantial progress towards establishing an evidence base, more remains to be accomplished in terms of addressing gaps in understanding of the true prevalence and impacts of childhood blindness and vision loss. All studies in this review cited the need for improved vision care services, either for all ages or for the childhood years in particular.

Braille use among Norwegian children from 1967 to 2007: trends in the underlying causes

PURPOSE

The aim of the study was to estimate the occurrence, diagnoses and time trends among Norwegian children that have received education in braille from 1967 to 2007.

METHODS

We used a retrospective population-based study design. The health care system is free for all inhabitants in Norway. We included all children that had received braille education the last four decades. From each student's record, we abstracted year born, country of birth, gender, year diagnosed, diagnosis, classification of visual impairment and type of reading media.

RESULTS

We identified 287 children (137 girls and 150 boys) that had received braille education over the last 40 years. Of these, 262 (91.3%) children were born in Norway, 145 (53.7%) were diagnosed within the first year of life and 59 (20.6%) from age of one to five. The most frequent diagnoses were Retinopathy of Prematurity (ROP), Juvenile Ceroid Lipofuscinoses (JNCL), Lebers Congenital Amaurosis (LCA) and Retinitis Pigmentosa (RP). Among the children, 63% (N = 170) used braille only, 9% (N = 25) braille and print, but priority braille, and 27% (N = 73) braille and print, priority print. The number of children with ROP using braille had a peak in 1977, then the number declined. The number diagnosed with LCA increased from 1987 to 1992. The number of braille users among children diagnosed with JNCL tended to increase substantially after 1992.

CONCLUSION

Braille education seemed to be dependent of trends in diagnoses as well as trends in recommendations from professional educators.

Screening for ocular dysfunction in children: approaching a common program

According to the general principles of screening, detection of visual impairment in children is worthwhile, since the condition is a serious health problem, reliable diagnostic tests are available and effective treatment is possible in most instances of ocular and visual dysfunction. However, an evaluation of the screening procedures has not been properly done and the cost-benefit of screening has not been studied. The aim of the present study is to perform a systematic analysis of the screening programs for detection of visual dysfunction. In the screening two parts can be separated, one that concerns the more serious ocular and visual conditions which have to be discovered by general survey methods very early in life, and one that involves detection of less serious conditions, mainly amblyopia, which can be diagnosed by testing for monocular reduction of visual acuity at about 3-4 years of age. The performance characteristics of the screening programs used in Sweden and Canada were evaluated and found to be very favourable. Based on the analysis and the evaluation, recommendations are made on programs for vision screening in children that could be applied more widely. The program could involve all or parts of the following: 1) A careful inspection of the eyes in the neonatal period and preferably also examination of the red reflex with the ophthalmoscope. 2) Children at high risk for ocular and visual disorder, i.e. those born prematurely before 32 weeks of age, or with genetic disease, hearing deficit and/or neurological and mental disorder, should be examined at the proper age by an ophthalmologist. 3) All staff at pediatric departments and child health care centers should be familiar with the visual development of the normal baby and should be alerted to the various symptoms and signs which first warn parents that there may be a visual defect. An inspection of the eyes to detect squint should be part of all pediatric examinations. 4) A screening test of monocular visual acuity in 4 year-old children can be reliably performed by non-ophthalmic personnel after proper training. The screening test should be repeated by school nurses during the first grade of school, and at regular intervals during the school years. 5) The children that screen positively should be seen by ophthalmologists, and in some cases by orthoptists, without undue delay for diagnosis and treatment.

[Risk factors and prevention of retinopathy of prematurity]

The history of retinopathy of prematurity (ROP) gives a prime example of how dangerous the uncontrolled introduction of a new medical treatment--particularly in the field of neonatology--may be. The most important risk factors for the development of ROP are the immaturity of premature infants as well as uncontrolled and/or inadequate treatment with oxygen. In comparison to the fetus, the premature infant is exposed to a nonphysiologically high oxygen concentration. This hyperoxia leads to formation of aggressive oxygen radicals on the one hand and, on the other hand, to temporarily reduced production of growth factors such as vascular endothelial growth factor and erythropoietin, which both play an important role in the pathogenesis of ROP. The most important measure to prevent ROP is restrictive and carefully monitored oxygen treatment. Medical treatment to prevent ROP includes injection of D-penicillamine and retinol, but the available data are still limited, particularly with regard to the long-term effects of this treatment. A higher oxygenation in prethreshold ROP does not lead to recovery of ocular findings, but it increases the incidence of pulmonary complications. A reduction of light intensity in neonatal intensive care units proved not to be efficient for preventing ROP. To avoid blindness, standardized screening of the risk group is needed.

A novel method of notification to profile childhood visual impairment in Scotland to meet the needs of children with visual impairment

The purpose of this study is to pilot a new notification system for children with visual impairment (VI) and describe the initial summary findings. A system of notification of children in Scotland with VI was established. Information concerning this system was distributed to professionals working with visually impaired children to forward to parents. Parents, teachers and health professionals were all encouraged to notify children with VI. 975 families with children with (VI) were notified and received information and support from Visual Impairment Scotland (VIS). For this review, the data from 850 parents were included in the analysis. The provision of a range of support services for parents and children with VI has led to a wide range of children being notified to VIS. The causes of VI can be recorded as well as other useful demographic information. The methods used could be applied across the range of low incidence childhood disabilities.

The association of indicators of fetal growth with visual acuity and hearing among conscripts

Impaired fetal growth is associated with increased susceptibility to several chronic diseases. We studied the association between birth weight, indicators of disproportional fetal growth, and impaired visual acuity and hearing in 4,300 conscripts from a well-defined region in Denmark from August 1, 1993, to July 31, 1994. From the standard health examination for conscripts, we obtained data on sight based on the Snellen's chart and data on hearing acuity based on audiometry. By means of record linkage, we obtained data on outcomes for the conscripts at birth from the Medical Birth Registry. From this registry, we have data on birth weight, gestational age, and birth length that were recorded from existing computerized registers based on the records of midwives. A birth weight of less than 3,000 gm and a body mass index at birth of less than 3.4 were associated with reduced visual acuity and impaired hearing. The results could be due to fetal brain programming or due to confounding, by early birth trauma or other factors.

Uniocular childhood blindness: a prospective study

PURPOSE

This prospective study examines uniocular blindness among children younger than 16 attending a large pediatric ophthalmology department. The aim was to identify the causes of uniocular blindness and determine how much is preventable. We defined blindness according to the World Health Organization definition of vision worse than or equal to 3/60.

METHODS

All children who attended the department and were blind in one eye during the period of the study were included. A history was taken, visual acuity was assessed by an age-appropriate method, and an ocular examination was carried out. When necessary, the child also was seen by an orthoptist or pediatrician.

RESULTS

A total of 71 patients were identified. At the time of diagnosis, the patients varied in age from a few weeks to 15 years. The causes were classified into one of the following diagnostic categories: chromosomal/genetic (8.5%), prenatal (47.9%), perinatal (7.0%), or childhood (36.6%). Many cases are prenatal in origin and are not preventable. Other causes that are difficult to prevent include retinoblastoma, toxocariasis, and trauma. One cause, amblyopia, may be preventable or treatable in most instances if detected early.

CONCLUSIONS

Most cases of uniocular blindness are not preventable; however, protective glasses should be encouraged to prevent injury to the good eye.