title: Characterization of human retinal vessel arborisation in normal and amblyopic eyes using multifractal analysis.
abstract: OBJECTIVE
  To characterize the human retinal vessel arborisation in normal and amblyopic eyes using multifractal geometry and lacunarity parameters.
  
  
  METHODS
  Multifractal analysis using a box counting algorithm was carried out for a set of 12 segmented and skeletonized human retinal images, corresponding to both normal (6 images) and amblyopia states of the retina (6 images).
  
  
  RESULTS
  It was found that the microvascular geometry of the human retina network represents geometrical multifractals, characterized through subsets of regions having different scaling properties that are not evident in the fractal analysis. Multifractal analysis of the amblyopia images (segmented and skeletonized versions) show a higher average of the generalized dimensions (Dq ) for q=0, 1, 2 indicating a higher degree of the tree-dimensional complexity associated with the human retinal microvasculature network whereas images of healthy subjects show a lower value of generalized dimensions indicating normal complexity of biostructure. On the other hand, the lacunarity analysis of the amblyopia images (segmented and skeletonized versions) show a lower average of the lacunarity parameter Λ than the corresponding values for normal images (segmented and skeletonized versions).
  
  
  CONCLUSIONS
  The multifractal and lacunarity analysis may be used as a non-invasive predictive complementary tool to distinguish amblyopic subjects from healthy subjects and hence this technique could be used for an early diagnosis of patients with amblyopia.
authors.affiliation: Discipline of Descriptive Geometry and Engineering Graphics, Department of Automotive Engineering and Transportation, Faculty of Mechanical Engineering, Technical University of Cluj-Napoca, Cluj-Napoca 400641, Cluj, Romania.
authors.forename: Stefan
authors.initials: S
authors.lastname: Tălu
authors.affiliation: Discipline of Ophthalmology, Department of Surgical Specialties and Medical Imaging, Faculty of Medicine, "Iuliu Hatieganu" University of Medicine and Pharmacy Cluj-Napoca, Cluj-Napoca 400012, Cluj, Romania.
authors.forename: Cristina
authors.initials: C
authors.lastname: Vlăduţiu
authors.affiliation: Department of Mathematics and Informatics, University of Palermo, Palermo 90123, Italy.
authors.forename: Carmen A
authors.initials: CA
authors.lastname: Lupaşcu
keywords: amblyopia; lacunarity; multifractals; retina; retinal vessels; strabismus