Arthur Cummings

Posted: Friday, October 2, 2015

The smartphone-based Portable Eye Examination Kit (Peek) can provide visual acuity measurements as accurate and repeatable as those obtained with Snellen or ETDRS logMAR charts, according to a new study published in JAMA Ophthalmology“Vision testing is a crucial part of an ophthalmic examination and we demonstrated that it was possible to create a test that was independent of language and could be performed by non-eye care workers,” the study’s lead author Andrew Bastawrous BSc, MRCOphthof the International Centre for Eye Health, London School of Hygiene and Tropical Medicine, UK, told EuroTimes in an interview.


This study involved 300 adults aged 55 years and older who were part of the six-year follow-up of the Nakuru Eye Disease Cohort in Kenya. All patients underwent visual acuity testing in their homes – performed by healthcare workers with basic eye care training – using both the smartphone-based Portable Eye Examination Kit (Peek) acuity test and a reduced “tumbling E” Snellen chart (Sussex Vision).

They also underwent the same testing at a local medical centre performed by the same healthcare worker, in addition to testing using retro-illuminated ETDRS charts, performed by an ophthalmic clinical officer, which served as a reference standard. The study was published online in JAMA Ophthalmology, 2015 (DOI:10.1001/jamaophthalmol.2015.1468).

The investigators found that visual acuity measured with the smartphone-based acuity test differed by a mean of 0.07 logMAR from measurements with the ETDRS chart, and by a mean of 0.08 logMAR from measurements with the reduced Snellen chart, less than one line of difference.

The Peek kit consists of an Android smartphone, a special lens attachment and a suite of diagnostic software. It is the result of a collaboration between the London School of Hygiene and Tropical Medicine, the University of Strathclyde and the NHS Glasgow Centre for Ophthalmic Research, UK.

“Overall the package of diagnostics being developed by Peek will allow task-shifting, moving away from requiring scarce specialist doctors and nurses to leave the hospital and find cases in the community, and moving towards having minimally skilled non-ophthalmic workers providing reliable exams closer to the patient, without the need for the eye worker or patient to travel,” Dr Bastawrous said.

He noted that he and his team are close to finalising for publication a study comparing image quality and interpretation of optic nerve photographs obtained with the Peek system to those obtained with a desktop camera, independently graded at Moorfields Eye Hospital. They have also recently completed a randomised controlled trial where teachers in Kenya tested the vision of 20,000 children using the Peek kit.


Andrew Bastawrous: