Detections of refractive risk factors for amblyopia with Plusoptix Autorefractor A09

Abstract

Amblyopia is the most frequent cause for decreased vision in childhood. Important risk factors for amblyopia (ARF) are refractive errors. The aim of this study was to examine the reliability of the Plusoptix Autorefractor A09 (POA09) to detect refractive ARF. This prospective non-blinded, one-armed study was conducted between February 2012 and September 2015. Children aged 6 months to 12years were screened in kindergarten and schools for refractive errors. Thresholds for screening failure were hyperopia ≥ 3.5 diopters(D), myopia ≥ 3.0 D, anisometropia ≥ 1.5 D and astigmatism ≥ 1.5 D (axis 90° or 180° ± 10°) or ≥ 1.0 D (≥ 10° axis deviation of 90° or 180°). Children who failed screening were advised to see an ophthalmologist for acomprehensive eye examination. After the visit, parents were asked for the results of the examination. Areference group of children who did not fail screening also received acomprehensive eye examination. Based on the number of children who failed screening, we calculated the proportion of correctly detected refractive errors. Based on the children of the reference group we calculated the proportion of correctly excluded refractive errors and the false negative rate. In this study 3170children were screened, 715children (22.3%) failed screening. For 460 of these (64.3%) follow-up was available and for 132children information on refractive errors in cycloplegia was available. Most frequent refractive errors at screening were astigmatism (90.9%) and anisometropia (11.4%). Most frequent refractive errors in cycloplegia were astigmatism (56.8%) and hyperopia (18.9%). The proportion of correctly detected refractive errors in the screening was highest for astigmatism (60%) and anisometropia (53.3%), followed by hyperopia (33.3%) and myopia (25%). The reliability of POA09 to detect refractive ARF in children without cycloplegia was limited, highlighting the importance of asystematic amblyopia screening. Ascreening in cycloplegia can increase the proportion of correctly detected refractive ARF and should be studied.