Effectiveness of screening preschool children for amblyopia: a systematic review

Abstract

Background: Amblyopia and amblyogenic factors like strabismus and refractive errors are the most common vision disorders in children. Although different studies suggest that preschool vision screening is associated with a reduced prevalence rate of amblyopia, the value of these programmes is the subject of a continuing scientific and health policy discussion. Therefore, this systematic review focuses on the question of whether screening for amblyopia in children up to the age of six years leads to better vision outcomes.

Danish Rural Eye Study: the association of preschool vision screening with the prevalence of amblyopia

“…A more recent Dutch study estimated that the country's screening programme had reduced the rate of amblyopia by 50% (de Koning et al 2013). However, whether the rate of amblyopia among adults who have received preschool vision screening is lower has not been established (Schmucker et al 2009). Of note, the rate of participation as well as the compliance in each vision screening programme will affect the success of the programme (Williams et al 2003;Beauchamp et al 2010).…”

Amblyopia: neural basis and therapeutic approaches

“…Even though there is not yet a consensus on the influence of age on treatment (48) , studies indicate that treatment initiated after 6 to 8 years of age has the lowest success rate (11,19,39,46) . Thus, it has been re commended to initiate treatment as early as possible (48,49) , even though 8-to 12-year-old chil dren may sometimes satisfactorily respond to therapy (39) . The severity of amblyopia also significantly affects treatment outcome, with the greatest rate of success found for mild amblyopia (47) .…”

“…This tends to augment visual acuity of the amblyopic eye and to improve binocular function, as long as it is correctly performed (39) . Treatment schedules vary from months to years (40) but last 3 years on average (39) . American and British guidelines both advise daily occlusion for 2 h for moderate and 6 h for severe amblyopia.…”

“…Parents' participation is essential for successful treatment; therefore, they should be aware of the necessity, urgency, and potential effectiveness of the therapeutic program (43) . Despite having been used for many years, occlusion therapy still needs to be investigated as to the neural events responsible for reversal of the symptoms (39) . Clarification is needed as to what is involved in the consolidation of visual neurophysiologic development driven by the effects of visual processing using the amblyopic eye.…”

“…The severity of amblyopia also significantly affects treatment outcome, with the greatest rate of success found for mild amblyopia (47) . Response to treatment is a function of initial visual acuity and treatment adherence (39,50) . For example, success in patients with mild amblyopia and good adherence to treatment is higher than 80%, whereas it is only about 15% in subjects with severe amblyopia and poor adherence (47) .…”