Phone apps could equal conventional eye tests for remote communities

UK researchers have used a phone app to test eyesight in Kenyan homes, and found it as good as conventional eye chart test in a clinic.

The test – called Peek (portable eye examination kit) Acuity – has been developed by the London School of Hygiene & Tropical Medicine, the University of Strathclyde and the NHS Glasgow Centre for Ophthalmic Research.

This is not a test to determine what glasses someone requires, but simply how good their eyesight is – with or without the glasses they normally wear.

To avoid language difficulties, the test uses a single ‘E’ made from a 5×5 matrix (see image) presented at different sizes and rotations of 0, 90, 180 or 270°.

Holding it 2m away from the subject – a distance chosen to be available inside a typical rural Kenyan home – the subject simply has to point in the same direction as the prongs of the E each time it is presented.

To record the subject’s response, the operator swipes the screen in the direction pointed. To avoid operator bias, the operator works from behind the phone – in this case a Samsung phone running Android.

Access to the phone’s light sensor allows the app to warn if ambient light is too bright for the test to be valid.

For the project, tests were done in or near the subject’s house, and at a mobile eye clinic.

“The research shows results from the app carried out on 233 people in their own homes and repeated in eye clinics based in Kenya were as reliable as those from standard paper-based charts and illuminated vision boxes in an eye clinic,” said the researchers.

The average difference between home test with the app and illuminated chart clinic tests were equivalent to less than one line on an eye chart.

Tests also showed people can be trained to operate Peek Vision accurately, without being heath care professionals.

“Our ultimate hope is that the accuracy and easy to use features of Peek will lead to more people receiving timely and appropriate treatment and be given the chance to see clearly again,” said Dr Andrew Bastawrous of the London School, and co-founder of an organisation called Peek.

Full results are available free from the journal JAMA Opthalmology.

Peek is working on a series of apps to test other eye-related issues – colour vision, contrast perception and retinal health are amongst them. To go with the last one, a clip-on retinal microscope for phones called Peek Retina is under development, which is the subject of an Indiegogo fund-raising campaign. 

Accurate  are amongst those under development.

Peek has an Indiegogo campaign

http://ift.tt/1SGjpBh

 

steve bush

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