Vision screening of Greenlandic children evaluating efficacy, coverage and future directions.

This thesis presents a comprehensive analysis of vision screening of children in Greenland, focusing on the efficacy of the current programme for six-year-old schoolchildren, the prevalence of vision impairment, amblyopia and refractive errors among six- and four-year-old children and the evaluation of a new screening method for preschool children. Additionally, it underscores the challenges of delivering consistent healthcare services in Greenland due to its vast and sparsely populated areas and the lack of prior research on vision health in Greenlandic children. The thesis involved three populations: two groups of six-year-old children, one with 2493 children from 2017 to 2022 and another with 517 children in 2017, and one group of 274 four-year-old children, all born in 2017. Key findings include an increase in screening coverage of schoolchildren from 43% to 61% from 2017 to 2022, although referral rates to ophthalmologists declined in the same period from 14% to 5% due to system inefficiencies. The prevalence of monocular amblyopia (≥0.3 logMAR) was 2% for both age groups, consistent with European and North American data. The prevalence of vision impairment was steady throughout the study period at 3% for the six-year-old children. Notably, Greenlandic children exhibit less severe vision impairment than in other regions, potentially due to genetic or environmental factors. However, they exhibited more hyperopia than African American and Chinese children but less than White American and Danish children. They also had higher myopia rates compared to Danish and indigenous Canadian children. The thesis highlights the importance of early detection and intervention for optimal visual development, emphasising a tailored approach for Greenlandic children. Improvements to the screening programme are suggested, including clear referral instructions, involvement of various healthcare professionals, such as optometrists, and enhanced parental awareness to increase coverage and ensure timely evaluations. It also suggests a new screening method incorporating a non-cycloplegic autorefraction to enhance the sensitivity and effectiveness of preschool children. Recommendations for screening methods and referral criteria for six- and four-year-olds are provided, along with an outline of the estimated costs of the new screening method. This thesis provides a basis for helping decision-makers in Greenland improve vision screening for Greenlandic children. Future research directions include assessing the quality of life of children with vision impairments, exploring the genetic and environmental determinants of myopia and leveraging technology to improve access to vision care for children in Greenland.