eye testOptometrists who rely on auto-refractors could be losing vital skills for preserving eye health in individuals with Down’s syndrome and other learning disabilities, according to research. 

Using retinoscopy can be important for picking up conditions such as keratoconus in their earliest stages. However, there are concerns that as more optometrists replace the retinoscope with auto-refracters, early keratoconus can be missed.

Keratoconus affects as many as 1 in 10 individuals with Down’s syndrome, a condition that leads to the loss of their vision when not diagnosed in the early stages. This has been attributed in part to the fact that people who have Down’s syndrome are less likely to report changes to their eye sight, therefore symptoms go unnoticed by family, friends and carers. 

In light of this research, the Down’s Syndrome Association is advocating the importance of retaining retinoscopy skills to optometrists, to ensure keratoconus is picked up in the earliest stages. This is supported by optometry experts as well as extensive research from the Down’s syndrome Vision Research Unit in Cardiff.

Optometrist Stephanie Campbell from the unit, said: “Just as in many spheres of life, optical practitioners are being seduced by technology, and in many optometric practices, the retinoscope is being replaced by auto-refractors. This poses dangers for individuals with Down’s syndrome whereby early keratoconus can pass un-noticed, or difficulty in obtaining a result with an auto-refractor can be attributed to the patient’s learning disability.”

Key findings from a study that measured a number of visual functions and characteristics of the eyes in a group of 45 young people with Down’s syndrome, aged 13 to 26 years, 11 of whom had keratoconus, by the Down’s syndrome Vision Research Unit, included: 

Eye-rubbing – long held to be a ‘cause’ of keratoconus in Down’s syndrome – does not distinguish those individuals at risk of keratoconus, and does not seem to be a cause of the condition at this stage

Measuring astigmatism, which is associated with keratoconus in the general population, does not distinguish those individuals at risk of keratoconus

Measuring visual acuity – the standard letter or picture chart – does not distinguish between healthy eyes and early keratoconus

Examining the health of the exterior eye under magnification does not distinguish between healthy eyes and early keratoconus

The quality of the retinoscopy reflex does distinguish between healthy eyes and early keratoconus.

In the study, all eyes with keratoconus had an abnormal retinoscopy reflex and all healthy eyes had a smooth reflex. This technique, which all optometrists are trained to use, “is the obvious key to detecting keratoconus in young people with Down’s syndrome,” said Campbell.

Other experts have also acknowledged the loss of retinoscopy skills as a real concern, specifically for vulnerable members of the public. Dr Maggie Woodhouse OBE, senior lecturer at Cardiff University’s School of Optometry & Vision Sciences, said: “I am very concerned that many optometrists are not using retinoscopy on a daily basis, and therefore losing this invaluable skill. Obviously, for people with Down's syndrome, it means that treatable conditions like keratoconus are inevitably going to be missed, but it also means that optometrists can't offer eye examinations to young children or anyone with learning disabilities who cannot use hi-tech instrumentation. It's as if optometrists are deliberately choosing to deny eye care to the most vulnerable members of our population”.

Carol Boys, chief executive of the Down’s Syndrome Association, added: “We are urging optometrists to retain their retinoscopy skills and safeguard the eye health of individuals with Down’s syndrome by using the necessary equipment to make informed assessments. We also ask that professionals ensure their knowledge around the visuals problems that affect people with Down’s syndrome is up to date, to ensure these individuals receive the best possible care.”