An image processing technique for diagnosis of Alzheimer s disease

BACKGROUND: Patients with Alzheimer s disease (AD) reportedly hibit hypersensitivity to much diluted tropicam solution (0.005%), a M4 muscarinic receptor antagonist. Therefore aocular application of 0.005% tropicamide ma be useful for screening dementia. The aim of this study was to simplify the pupil response test by using a new image analyzing system, which consists of a cheap, simple, and easy to use web-camera and a computer. METHODS: Intraocular tropicamide of 0.005% concentration was administered in 3 groups: Alzheimer s disease patients (n = 8, average age = 76 ± 5), non-Alzheimer s disease elderly (n = 6, average age = 65 ± 7), and young subjects (n = 8, average age = 28 ± 5). Every 5 minutes for 60 minutes, image of the eye s shape were taken, and the diameter of the pupils was measured. RESULTS: The results showed that differences in pupil dilation rate between Alzheimer s disease and non-Alzheimer s disease subjects were statistically significant. ROC analysis showed that after 35 minutes the sensitivity and specificity of the test were 100%. CONCLUSIONS: Based on our results, we concluded that this recording system might be an appropriate and reliable tool for pupil response diagnosis test of Alzheimer s disease.