Eyeworld

EW GLAUCOMA 52 April 2015 O ne of the biggest challenges of glaucoma is that many—if not most—don't know they have it. This emphasizes the key role of screening. In this month's "Glaucoma editor's corner of the world," Chris A. Johnson, PhD, shares his experience using an iPad visual field testing app in Nepal. Dr. Johnson is one of the world's foremost visual field experts, and he has taken up the challenge of de- veloping the optimal screening process for glaucoma. The iPad visual field test is a very efficient and accurate way to identify people who have glaucoma as well as diabetic eye disease. Dr. Johnson's study would not have been possible without the collaboration of Suman Thapa, MD, a glaucoma specialist in Kathmandu. Dr. Thapa is one of only a few glaucoma specialists who serve all of Nepal—a population of more than 27 million people or about the same number of people who live in Texas. So Dr. Thapa is working with a huge need for accurate screening. Fortunately, Dr. Thapa also has advanced training in epidemiology and is active in many international organizations. From his perspective the problem is not just identifying the people with glaucoma; it is also critically important to reduce the rate of false positives since this could save a patient the time and expense of a trip from a remote village in the Himalayas to Kathmandu. An efficient and accurate visual field test that works well in Nepal may also be very effective everywhere else—includ- ing the U.S. The screening technology developed by Drs. Johnson and Thapa may one day help glaucoma patients all over the world. Reay H. Brown, MD, glaucoma editor by Maxine Lipner EyeWorld Senior Contributing Writer Glaucoma testing in Nepal S creening is a vital part of glaucoma management, said Chris A. Johnson, PhD, professor of oph- thalmology, University of Iowa, Iowa City. "Around half of the people in the United States who have glaucoma aren't aware that they have it," he said. "But it's even more prevalent in underdeveloped areas of the world, especially in places like Nepal, India, Africa, and parts of South America where people don't have eye exams, so it can be fairly advanced before it's ever detected." One option to increase accessi- bility to screening in remote Nepal is the use of an iPad (Apple, Moun- tain View, Calif.), a possibility that Dr. Johnson has been exploring. The Visual Fields Easy app on the tablet was used to screen more than 400 eyes for glaucoma, he reported. Use of the iPad was spurred by logistics. The usual frequency doubling device that researchers had been using for glaucoma screening in remote areas of India and other countries was simply impractical at Nepal's high altitudes, he explained. "Carrying an instrument that is 30 or 40 pounds is impossible," he said. "So we looked to do some- thing that would be more portable and that wouldn't require having electricity all the time." The tablet seemed like a natural answer. Screening on screen With the iPad app, a luminescent background is used with small spots of light that appear in different loca- tions, Dr. Johnson said. "The person looks at a red dot there to keep the eye steady," he said. "Then it will present flashes of light in other regions and the person responds when they see a spot, and if they don't respond, then they didn't see the spot." Results came out better than expected, Dr. Johnson reported. iPad ophthalmic screening at the top of the world continued on page 54 While use of hand-held instrumentation for screenings can easily be done in remote regions, bulkier machines can be difficult to transport. Source: Chris A. Johnson, PhD Use of a portable iPad was a natural for conducting glaucoma screenings in remote areas of Nepal. Glaucoma editor's corner of the world

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