Measurement of Retinal Sensitivity on Tablet Devices in Age-Related Macular Degeneration

Abstract

Purpose: We compared measurements of central retinal sensitivity on a portable, lowcost tablet device to the established method of microperimetry in age-related macular degeneration (AMD).Methods: A customized test designed to measure central retinal sensitivity (within the central 18 radius) on a tablet device was developed using an open-source platform called PsyPad. A total of 30 participants with AMD were included in this study, and all participants performed a practice test on PsyPad, followed by four tests of one eye and one test of the other eye. Participants then underwent standardized microperimetry examinations in both eyes. Results:The average test duration on PsyPad was 53.9 6 7.5 seconds, and no significant learning effect was observed over the examinations performed (P ¼ 1.000). The coefficient of repeatability of central retinal sensitivity between the first two examinations on PsyPad was 61.76 dB. The mean central retinal sensitivity was not significantly different between PsyPad (25.7 6 0.4 dB) and microperimetry (26.1 6 0.4 dB, P ¼ 0.094), and the 95% limits of agreement between the two measures were between À4.12 and 4.92 dB. Conclusions:The measurements of central retinal sensitivity can be performed effectively using a tablet device, displaying reasonably good agreement with those obtained using the established method of microperimetry.Translational Relevance: These findings highlight the potential of tablet devices as low-cost and portable tools for developing and performing visual function measures that can be easily and widely implemented.

A Comparison of Perimetric Results from a Tablet Perimeter and Humphrey Field Analyzer in Glaucoma Patients

“…The fact that the Apple iPad can return sound estimates of thresholds confirms a similar finding for foveal thresholds reported by Wu et al 4 who compared an iPad-based test applied to 30 patients with ARMD against outcomes returned by a commercial microperimeter. This group tested foveal sensitivity (within 1° of fixation) using the same test grid locations in both instruments.…”

“…The instructions and training required for these patients to achieve reliable visual field results on MRF needs to be developed. Nevertheless, our current data, and that of Wu et al, 4 indicates that reliable outcomes can be readily achieved on an iPad perimeter when administered by trained assistants. This makes the present implementation of iPad a potentially useful device for the purpose of telemedicine or remote-site testing, provided it is administered by trained personnel.…”

“…Portable tablet devices have been shown to be useful in visual acuity and contrast sensitivity testing as well as for retinal sensitivity estimates in foveal locations. 4–6 The extension of a portable tablet device to peripheral visual field testing, as detailed here, has the potential to allow detection and management of glaucoma in communities where access to traditional field testing machines is limited. Furthermore it will allow future investigation into the use of such testing devices in terms of home monitoring, especially as ownership of tablet devices is increasing in the average household.…”

“…Recent growth of portable tablet devices such as the iPad (Apple, Cupertino, CA) have seen these devices become suitable as low-cost, portable, and reliable vision testing instruments due to its good dynamic range of luminance and high spatial resolution. 2–4 Portable tablet devices have been shown to be useful in tests of visual acuity and contrast sensitivity, and for the assessment of macular sensitivity. 4–6 The development of a tablet-based perimeter follows from an early suprathreshold test developed on iPad generation 1 (Visual Field Easy app), which was found to be useful in visual field screening in Nepal.…”

“…2–4 Portable tablet devices have been shown to be useful in tests of visual acuity and contrast sensitivity, and for the assessment of macular sensitivity. 4–6 The development of a tablet-based perimeter follows from an early suprathreshold test developed on iPad generation 1 (Visual Field Easy app), which was found to be useful in visual field screening in Nepal. 7 For a tablet based perimeter to be useful in monitoring and in detecting early changes in the visual field, it needs to be able to return threshold estimates.…”