title: Distribution of normal superficial ocular vessels in digital images.
abstract: OBJECTIVE
  To investigate the distribution of different-sized vessels in the digital images of the ocular surface, an endeavor which may provide useful information for future studies.
  
  
  METHODS
  This study included 295 healthy individuals. From each participant, four digital photographs of the superior and inferior conjunctivae of both eyes, with a fixed succession of photography (right upper, right lower, left upper, left lower), were taken with a slit lamp mounted camera. Photographs were then analyzed by a previously described algorithm for vessel detection in the digital images. The area (of the image) occupied by vessels (AOV) of different sizes was measured. Height, weight, fasting blood sugar (FBS) and hemoglobin levels were also measured and the relationship between these parameters and the AOV was investigated.
  
  
  RESULTS
  These findings indicated a statistically significant difference in the distribution of the AOV among the four conjunctival areas. No significant correlations were noted between the AOV of each conjunctival area and the different demographic and biometric factors. Medium-sized vessels were the most abundant vessels in the photographs of the four investigated conjunctival areas. The AOV of the different sizes of vessels follows a normal distribution curve in the four areas of the conjunctiva. The distribution of the vessels in successive photographs changes in a specific manner, with the mean AOV becoming larger as the photos were taken from the right upper to the left lower area.
  
  
  CONCLUSIONS
  The AOV of vessel sizes has a normal distribution curve and medium-sized vessels occupy the largest area of the photograph.
authors: Retina Research Centre, Mashhad University of Medical Sciences, Mashhad, Iran. Electronic address: tkbanaee@gmail.com.
authors: Touka
authors: T
authors: Banaee
authors: Refractive Error Research Centre, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran.
authors: Asieh
authors: A
authors: Ehsaei
authors: Computer Engineering Department, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran.
authors: Hamidreza
authors: H
authors: Pourreza
authors: Department of Social Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
authors: Mohammad
authors: M
authors: Khajedaluee
authors: Retina Research Centre, Mashhad University of Medical Sciences, Mashhad, Iran.
authors: Mojtaba
authors: M
authors: Abrishami
authors: Retina Research Centre, Mashhad University of Medical Sciences, Mashhad, Iran.
authors: Mohsen
authors: M
authors: Basiri
authors: Retina Research Centre, Mashhad University of Medical Sciences, Mashhad, Iran.
authors: Ramin
authors: R
authors: Daneshvar Kakhki
authors: Computer Engineering Department, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran.
authors: Reza
authors: R
authors: Pourreza
mesh_terms: D000328:Adult; D000465:Algorithms; D001794:Blood Pressure / Q000502:physiology; D001808:Blood Vessels / Q000033:anatomy & histology*; D001824:Body Constitution; D003228:Conjunctiva / Q000098:blood supply*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D010781:Photography / Q000295:instrumentation*
keywords: Conjunctiva; Digital image; Ocular vessel; Photography