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Gautam Vangipuram, Cecilia S Lee, Aaron Y. Lee; CAPTCHA performance in patients with active macular disease. Invest. Ophthalmol. Vis. Sci. 2018;59(9):5174. doi: https://doi.org/.
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© ARVO (1962-2015); The Authors (2016-present)
CAPTCHA (Completely Automated Turing test to tell Computers and Humans Apart) was designed as a test to prevent spam prevention. In patients with visual impairment, completion of this task has been assumed to be difficult, but no published data exists on its underlying mechanism. As overall visual function is not well measured by Snellen visual acuity alone, we hypothesized that CAPTCHA performance may provide additional information on macular disease activity related visual dysfunction.
Prospective cohort pilot study. Active disease was defined as the presence of either intra-retinal (IRF) or sub-retinal (SRF) fluid on spectral-domain optical coherence tomography. CAPTCHA performance was tested using 10 randomized prompts. In addition, near and distance VA, contrast sensitivity, and reading speed using a standardized paragraph were measured. Pseudophakic control patients were blurred to match visual acuity ranging from 20/20-20/50. Primary outcome measures were edit distance and % of correct responses of CAPTCHA.
77 patients were recruited; 40 with active macular disease and 37 control subjects. Distance visual acuity was significantly different between both IRF vs control (p<0.01) and SRF vs control (p<0.01). Similarly, contrast sensitivity was found to be significantly different in both the IRF (p<0.01) and SRF groups (p<0.01) vs VA matched controls. No significant difference was found between reading speed of active disease and control patients, average edit distance of active disease and control patients (1.6±0.8 versus 1.5±1.1, p=0.063), or between % correct of active disease and control patients (34.9±20.5 versus 42.9±19.9, p=0.091). (Figure) The goodness of fit for the logistic regression models for the outcome of either IRF or SRF did not improve accounting for average edit distance (p=.489, p=.270) or % correct (p=.892, p=.613) in the model.
Distance VA and contrast sensitivity are positively correlated with the presence of IRF and SRF in active macular disease. CAPTCHA performance did not appear to be a significant predictor of either IRF or SRF in our pilot study. Poor CAPTCHA performance in patients with macular disease may be attributable to other pathophysiology than intra/subretinal fluid such as inner retinal dysfunction.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.
Contrast sensivity, reading speed, average edit distance and percent correct responses vs. visual acuity for active macular disease and pseudophakic control patients.
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