title: An image processing technique for diagnosis of Alzheimer's disease.
abstract: BACKGROUND
  Patients with Alzheimer's disease (AD) reportedly exhibit hypersensitivity to much diluted tropicamide solution (0.005%), a M4 muscarinic receptor antagonist. Therefore intraocular application of 0.005% tropicamide may 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.
authors.affiliation: Razi Institute for Drug Research, Department of Pharmacology, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Massoud
authors.initials: M
authors.lastname: Mahmoudian
authors.forename: Soltan Ahmed
authors.initials: SA
authors.lastname: Ebrahimi
authors.forename: Zahra
authors.initials: Z
authors.lastname: Kiani