Amblyopia Screening in Finland
Elina Karvonen, MD; Ilkka-Petri Välitalo, MD; Johanna Liinamaa, MD, PhD
Department of Ophthalmology, PEDEGO research unit and Medical research center, University of Oulu and Oulu University Hospital, Finland
Introduction: Amblyopia screening is well organized in Finland since there are annual vision screenings in all children aged 3 to 7 years. Referral criteria for asymptomatic children are: (1) the suspicion of amblyogenic factors in children aged under 3 years, (2) bilaterally reduced visual acuity (VA) (<0.5 in 3–4-year olds, <0.63 in 5–6-year olds or <0.8 in 7-year olds), (3) suspected unilateral amblyopia (³2 lines) or (4) manifest squint. This study explores the need for follow-up and treatment among referred children.
Methods: Retrospective data was collected on 110 consecutive children aged under 10 years at the initial visit to Oulu University Hospital in 2012.
Results: Intermittent tropia (43%), bilaterally reduced VA (33%) and suspected unilateral amblyopia (15%) were the main reasons for referral. The mean age was 4.0 years (SD 1.9). Up to 75% of the referral letters fulfilled the defined criteria with odds ratio of 5.1 (95 % CI 2.0-12.9) for the need of follow-up.
Emmetropia was found in 64%, hyperopia in 16%, myopia in 6% pure astigmatism in 14% and anisometropia in 36% of the children. Esodeviation was present in 25% and exodeviation in 28%. Prevalence of amblyopia was 16% (anisometropic 53%, strabismic 12% and combined 35%).
Of the 110 subjects, control visit was scheduled for 67 (61%) and treatment was started for 54 (49%). Spectacles were prescribed for 47 (43%) and patching was started for 19 (17%). No control visit or treatment was needed for 36 (33%) of the subjects.
Discussion: Two-thirds of the referred children need follow-up and every second child needs treatment. The nationally defined referral criteria for each age category are relevant and they should be adhered to.
Conclusion: The present referral criteria for asymptomatic children predict the need for follow-up well.
References: Pascual M, Huang J, Maguire MG, et al; Vision In Preschoolers (VIP) Study Group. Risk factors for amblyopia in the vision in preschoolers study. Ophthalmology 2014;121(3):622-629.
Arnold RW. Amblyopia risk factor prevalence. J Pediatr Ophthalmol Strabismus 2013;50(4):213-217.
Grossman DC, Curry SJ, Owens DK, et al. Vision Screening in Children Aged 6 Months to 5 Years: US Preventive Services Task Force Recommendation Statement. JAMA 2017;318(9):836-844.