Preparation of the Early Glasses Study: a randomized, controlled trial investigating the effect of early glasses for high refractive error on the development of amblyopia

Abstract

Purpose : Photorefraction of young children is currently practiced nation-wide in Flanders, Belgium, at age one. Children with high refractive error are referred to an ophthalmologist and mostly prescribed glasses. Wearing of glasses has increased from 4.7% to 6.4% in four-year-olds in Flanders between 2012 and 2017 but it is unknown how many cases of amblyopia have been prevented from developing by the prescription of early glasses. In a randomized controlled trial (RCT), we will establish whether early glasses for high refractive error at age one reduce the development of amblyopia between age one and four. As a secondary outcome early literacy will be compared in groups with and without glasses.

Methods : In preparation of the RCT, Children's Healthcare Centers (CHCs), research-orthoptists and facilities for the examination of children were recruited. Youth healthcare physicians were contacted in most healthcare regions in the Netherlands, to engage clusters of CHCs in child-rich neighborhoods. Research-orthoptists were sought via orthoptic professional societies, meetings and announcements. Locations for examination of the children were sought among institutions for visually impaired, CHCs and hospitals.

Results : Five preventive healthcare organizations will participate with one cluster of CHCs in Utrecht: Neighborhood Leidsche Rijn, one cluster in Harderwijk, Ermelo and Putten, one cluster in Tiel, Geldermalsen and Culemborg, one cluster in Eindhoven-North, and one cluster in Venlo and Roermond. Study locations were ensured in two institutions for visually impaired, one in a CHC and one in a hospital. So far four study orthoptists have been engaged for retinoscopy in cycloplegia at age one, and randomization of children surpassing the AAPOS 2003 criteria and follow-up until age four.

Conclusions : Sufficient CHCs, youth healthcare physicians and nurses and research-orthoptists have committed themselves to this RCT. When the relation between the size and sort of refractive error at age one or two and the increased odds to develop amblyopia will have been established objectively, the use of practice-based referral criteria will no longer be necessary.

This is a 2021 ARVO Annual Meeting abstract.