Visual impairment in Nordic children. II. Aetiological factors
Related Experiment Videos
T Rosenberg1, T Flage, E Hansen
1National Eye Clinic for the Visually Impaired, Copenhagen.
Insights
Prenatal factors, including genetics, cause most childhood visual impairment in industrialized nations. Understanding these causes and improving perinatal care are key to prevention.
Area of Science:
- Ophthalmology
- Pediatrics
- Genetics
Background:
- Childhood visual impairment presents a significant public health challenge in industrialized nations.
- Effective prevention strategies necessitate a thorough understanding of etiological factors contributing to vision loss in children.
- Existing data highlights the need for refined classification systems for childhood eye disorders.
Purpose of the Study:
- To analyze and classify etiological factors contributing to visual impairment in children within Nordic countries.
- To introduce a novel etiological classification system for childhood visual impairment based on causal factors and their onset.
- To identify key areas for future prevention efforts in childhood blindness and low vision.
Main Methods:
- Collaborative study (NORDSYN) involving four Nordic national registers of visual impairment.
- Analysis and classification of etiological factors for visual impairment in 2527 children.
- Development and application of a new etiological classification system based on causal factor type and debut.
Main Results:
- Prenatal factors, including genetic causes, were identified in 66% of cases (74% in children without additional impairments).
- Genetic factors comprised over half of prenatal cases; causes remained obscure in 40% of prenatal visual impairments.
- Perinatal factors were identified in 20% of cases, while infantile-juvenile factors were implicated in only 7%.
Conclusions:
- Prenatal factors are the predominant cause of childhood visual impairment in the Nordic region.
- Further research into non-genetic prenatal factors, gene expression regulation, and enhanced perinatal care is crucial for prevention.
- A comprehensive etiological classification system is essential for targeted prevention of childhood vision loss.
Abstract:
Careful clinical-aetiological assessment of visually impaired children is one of the prerequisites for prevention of future, 'unavoidable' cases of visual impairment of children in the industrialized part of the world. In a collaborative study (NORDSYN) between four Nordic national registers of visual impairment, we analysed and classified some of the factors considered to be essential components for the development of low vision or blindness in children. We discuss the conceptual basis for aetiological classification of eye disorders and visual impairment. An aetiological classification system, based on the type and debut of an essential causal factor is introduced. We present data on 2527 visually impaired children from the Nordic countries. In accordance with several other reports from the last twenty years it is demonstrated that prenatal factors, including genetic aetiologies, were involved in a large proportion (66%) of the cases. In children without additional impairments the corresponding fraction was 74%. Genetic factors accounted for a little over half of the prenatal cases, and in a substantial number of children (40%) with visual impairments of prenatal origin, the causes were obscure. In 1/5 of the material some peri-neonatal causal or modifying factor was identified. In 7% only, the presumed aetiological factor was introduced in the infantile-juvenile period of life. Further prevention of visual impairment among children of the industrialized countries would benefit most from a more comprehensive understanding of prenatal, nongenetic causal factors, further knowledge about regulating mechanisms responsible for gene expression, and additional improvements in perinatal care.