Performance of an iPad Application to Detect Moderate and Advanced Visual Field Loss in Nepal

• Published in: American journal of ophthalmology Vol. 182; pp. 147 - 154
• Main Authors: Johnson, Chris A., Thapa, Suman, George Kong, Yu Xiang, Robin, Alan L.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.2017; Elsevier Limited
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Computers, Handheld; Cross-Sectional Studies; Developing Countries; Diabetes; Diabetic retinopathy; Diabetic Retinopathy - diagnosis; Diabetic Retinopathy - epidemiology; Diabetic Retinopathy - physiopathology; Female; Glaucoma; Glaucoma - diagnosis; Glaucoma - epidemiology; Glaucoma - physiopathology; Gonioscopy; Humans; Intraocular Pressure - physiology; Male; Medical screening; Middle Aged; Mobile Applications; Nepal - epidemiology; Ophthalmology; Ophthalmoscopy; Optic Disk - pathology; Optic nerve; Optic Nerve Diseases - diagnosis; Optic Nerve Diseases - epidemiology; Optic Nerve Diseases - physiopathology; Performance evaluation; Photography - instrumentation; Population; Prospective Studies; Reproducibility of Results; Sensitivity and Specificity; Visual Acuity - physiology; Visual Field Tests - instrumentation; Visual Fields - physiology; Visual impairment; United States > US; Nepal; California
• ISSN: 0002-9394; 1879-1891; 1879-1891
• DOI: 10.1016/j.ajo.2017.08.007

To evaluate the accuracy and efficiency of Visual Fields Easy (VFE), a free iPad app, for performing suprathreshold perimetric screening. Prospective, cross-sectional validation study. We performed screening visual fields using a calibrated iPad 2 with the VFE application on 206 subjects (411 eyes): 210 normal (NL), 183 glaucoma (GL), and 18 diabetic retinopathy (DR) at Tilganga Institute of Ophthalmology, Kathmandu, Nepal. We correlated the results with a Humphrey Field Analyzer using 24-2 SITA Standard tests on 373 of these eyes (198 NL, 160 GL, 15 DR). The number of missed locations on the VFE correlated with mean deviation (MD, r = 0.79), pattern standard deviation (PSD, r = 0.60), and number of locations that were worse than the 95% confidence limits for total deviation (r = 0.51) and pattern deviation (r = 0.68) using SITA Standard. iPad suprathreshold perimetry was able to detect most visual field deficits with moderate (MD of −6 to −12 dB) and advanced (MD worse than −12 dB) loss, but had greater difficulty in detecting early (MD better than −6 dB) loss, primarily owing to an elevated false-positive response rate. The average time to perform the Visual Fields Easy test was 3 minutes, 18 seconds (standard deviation = 16.88 seconds). The Visual Fields Easy test procedure is a portable, fast, effective procedure for detecting moderate and advanced visual field loss. Improvements are currently underway to monitor eye and head tracking during testing, reduce testing time, improve performance, and eliminate the need to touch the video screen surface.