Abstract
PURPOSE: Photoscreening assesses risk factors for amblyopia, as an alternative to measurement of visual acuity (VA) to detect amblyopia, on the premise that its early correction could prevent development of amblyopia. We studied implementations of Plusoptix photoscreening in existing population-based screening in Flanders and Iran. METHODS: In Flanders, VA is measured at age 3, 4 and 6, photoscreening was added to existing screening at age 1 and 2.5 years in 2013. In Iran, VA is measured at ages 3-6 years, photoscreening was added at ages 3-6 years between 2011 and 2016. Plusoptix use was analysed in the literature for detection of risk factors for amblyopia and amblyopia itself, for ages 0-3 and for 4-6. A questionnaire, containing seven domains: existing vision screening, addition of photoscreening, implementation in screening program, training, attendance, diagnosis and treatment, and costs was distributed. In Iran, screening procedures were observed on site. RESULTS: Implementation of Plusoptix photoscreening was mainly analysed from questionnaires and interviews, its effectiveness from literature data. In Flanders, of 56 759 children photoscreened at age one (81% of children born in 2013), 9.2% had been referred, 13% of these were treated, mostly with glasses, resulting in an increase of 4-year-old children wearing glasses from 4.7% to 6.4%. In Iran, 90% of children aged 3-6 years participated in vision screening in 2016, but only those who failed the vision test were subjected to photoscreening. CONCLUSIONS: In Flanders, the use of Plusoptix photoscreening at ages 1 and 2.5 resulted in an increase of children wearing glasses, but it remains unknown how many cases of amblyopia have been prevented. Studies are needed to determine the relation between size and sort of refractive error and strabismus, and the increased chance to develop amblyopia.