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Emmanouil Tsamis, Cecilia Fenerty, Robert Harper, Tariq Aslam, David Henson; Performance Evaluation of a Novel Computer-Based Self-Administered Visual Field Screening Test for Glaucoma. Invest. Ophthalmol. Vis. Sci. 201657(12):.
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© 2017 Association for Research in Vision and Ophthalmology.
The risk of future visual impairment from chronic open angle glaucoma increases with late presentation. Due to its asymptomatic nature at early stages early detection only occurs through screening normally carried out by optometrists. Those not seeking optometric care are more likely to present late and at greater risk of future visual impairment. A new approach for glaucoma screening is the development and distribution of a self-administered visual field (VF) test that can run on a wide range of personal computers. Early work led to the development of such a test whose diagnostic performance is evaluated in this presentation
The new test uses a multiple stimulus supra-threshold algorithm to test a 20 location subset of the 24-2 pattern. One eye of 140 patients with no VF loss were tested 4 times; once without a simulated defect and with 3 different simulated glaucoma defects randomly selected from a pool of 30 defects (10 from stages 1-3 of the Glaucoma Staging System 2). Location and depth of the defects were derived from stable diagnosed glaucoma cases tested with a 24-2 SITA threshold algorithm on a Humphrey perimeter. In simulation cases the intensity of the presented stimuli were attenuated by the defect values of the randomly selected case with appropriately added variability. All patients performed the test on a Dell XPS 12 laptop with a background luminance of ~0.39 cd/m2 and a supra-threshold increment of 10dB. During analysis estimates of sensitivity, specificity and positive and negative predictive value were calculated at different cut-off criteria. Patients followed the written instructions on the screen including a demonstration trial while a researcher remained in the room for further support if needed
All patients completed the self-administered tests with little, if any, help from the researcher. The sensitivity and specificity of the new test on detecting glaucomatous Stage 1 defects were 93.5 and 97.1% respectively with 1 missed location as cut-off criteria, see figure. For stages 2 and 3 the sensitivities were 97.8 and 99.2% with specificities of 97.1%. Median testing time was ~155 secs/test (i.e. ~2.5 mins – IQR 41.5 secs)
The newly developed self-administered screening test was well received by patients and was shown to have high discriminatory power and is thus suitable for distribution to high-risk patients for self-testing
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.
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