Free iPad App Enables Inexpensive Visual Field Screening

Lara C. Pullen, PhD

November 04, 2014

CHICAGO — The free visualFields easy app for the iPad has made it possible to perform visual field screenings in remote areas of the world where access to bulky medical equipment is limited, a new study shows.

"Carrying equipment through mountain passes is very difficult," explained lead researcher Chris Johnson, PhD, director of the Visual Field Reading Center at the University of Iowa in Iowa City. He said he is pleased that his team appears to have solved the problem. "I was very impressed with how well this screening procedure did," he said here at the American Academy of Ophthalmology (AAO) 2014 Annual Meeting.

The study was designed to assess the ability of the low-cost program for the iPad to perform visual screening in Nepal.

Testing with the app took an average of 3 minutes and 18 seconds. Researchers compared results from the app with those from the Humphrey automated field analyzer, and used a comprehensive eye examination to establish the diagnosis.

For the number of missed test points, the correlation between the app and Humphrey automated field analyzer measures was good, Dr Johnson reported. He described the mean deviation correlation of 0.79 as "remarkable".

Table. Correlation Between the iPad App and Standard Visual Test

Standard Test Correlation With the App, r
Mean deviation 0.79
Pattern standard deviation 0.60
Total deviation 0.51
Pattern deviation 0.68


However, the app has a high rate of false-positive results for normal patients. "It is not designed to look for the earliest signs of glaucoma, but rather more moderate or advanced glaucoma," he explained.

The app provides a "specific, tangible benefit," said Andrew Iwach, MD, clinical spokesperson for the AAO, who was not involved in the research.

Glaucoma can progress and "the patient would not know that they are losing vision," he told Medscape Medical News. This app helps to identify patients who are at risk for vision loss.

We want to save sight worldwide.

The app stands in contrast to the large beautiful machines that dotted the floor in the exhibit hall at the meeting, drawing crowds of ophthalmologists eager to see the latest technology. Not only is it far smaller and less flashy, it is also much less expensive.

As ophthalmologists, "we are sharing with the world that this is available. We don't want to leave anyone behind," said Dr Iwach. "These are solutions and tools that we can use today; they can be used internationally; they can be used remotely." He noted that iPads can already be found in remote areas and their presence can be leveraged for health.

In fact, Dr Johnson said he has plans to spread the technology throughout the world. "We are expanding this into India and other places. I think this may be the wave of the future," he said.

"It's an exciting time," said Dr Iwach, who was eager to talk about the visualFields easy app in the larger context of innovations at the meeting. "We want to save sight worldwide," he said, adding that the AAO meeting is the largest meeting of eye surgeons and ophthalmologists in the world.

Dr Johnson is a consultant with Haag-Streit. Dr Iwach has disclosed no relevant financial relationships.

American Academy of Ophthalmology (AAO) 2014 Annual Meeting: Abstract PO412. Presented October 20, 2014.


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