We usually think of amblyopia, which affects one in 50 children (NHS, 2019), as a condition primarily impacting patients in their childhood years. But its consequences in adult life can also be far-reaching. So how should optometrists help adults manage the condition as they grow older?
Much depends on how early amblyopia is detected. Successful treatment depends on early diagnosis, and emphasising the importance of national screening programmes to ensure children with amblyopia are identified at a young age. Dr Paramdeep Bilkhu MCOptom, Clinical Adviser for the College, says: “If amblyopia is diagnosed and treated early enough, in the vast majority of cases it’s highly successful, and vision is restored either to normal or near-normal level.”
Some groups are at higher risk of developing the condition than others. Ann Webber, an Associate Professor in the School of Optometry and Vision Science at Queensland University of Technology in Australia, says: “In premature or low birthweight children or those with neurodevelopmental anomalies, there is greater risk of amblyopia, due to a greater prevalence of high refractive error and strabismus. Among very small premature babies, more will have high refractive error or strabismus and subsequent amblyopia than children born at full term.”
In practice, not every case of amblyopia is diagnosed in time, and not all children with a diagnosis complete their treatment. The most common cause of amblyopia is strabismus, which is often intermittent, so can be diagnosed after the age of three months (NHS, 2020).
The second most common cause, anisometropic amblyopia, can be picked up either at a routine eye appointment or at vision screening offered in the school Reception year. A Freedom of Information request made before the pandemic by the British and Irish Orthoptic Society (BIOS) and Clinical Council for Eye Health Commissioning (CCEHC) found that 94% of local authority areas in England offered vision screening to children, but only 47% of those were fully compliant with the service specifications recommended by Public Health England: screening should be offered to all children aged between four and five, be orthoptist-led, use standardised and validated methods, and be recorded on the child health information system (BIOS and CCEHC, 2020).