title: Rapid dynamic changes of the geometry of the anterior segment of the eye: A method of automatic spatial correction of a temporal sequence of OCT images.
abstract: BACKGROUND
  Ocular dynamics is a very complex phenomenon which has not been well studied and understood yet. The way in which the eye responds to pulsatile changes of the blood pressure or even the electric activity of the heart depends not only on the mechanical properties of each individual structure of the eye globe, but also on its internal conditions, such as the degree of accommodation or intraocular pressure (IOP).
  
  
  METHODS
  This paper presents a method for correcting these undesired movements that could increase the sensitivity of the technique and its reliability in the estimation of pulsatile dynamics. The presented algorithm uses fully automatic detection of the structures that form an angle and fully automatic stabilisation of each individual image being a part of a captured sequence.
  
  
  CONCLUSIONS
  The procedures described above were applied to the data of nine subjects taking part in the study. For all of them it turned out that the most representative area for fitting the images is the area of the irido-corneal angle apex. The presented algorithm significantly improved the spatial stability of the images in the temporal sequences of the tomographic images. The use of such correction makes it possible to distinguish the subtle pulsatile fluctuations of the ocular structures in the anterior segment, that can be associated with the activity of the retinal blood vessels and/or electric activity of the heart, from the undesired involuntary movements of the eye or the whole head.
authors.affiliation: Computer Science Institute, The University of Silesia in Katowice, Bedzinska 39, 41200 Sosnowiec, Poland. Electronic address: koprow@us.edu.pl.
authors.forename: Robert
authors.initials: R
authors.lastname: Koprowski
authors.affiliation: Institute of Physics, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50370 Wroclaw, Poland. Electronic address: damian.siedlecki@pwr.wroc.pl.
authors.forename: Damian
authors.initials: D
authors.lastname: Siedlecki
authors.affiliation: Institute of Physics, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50370 Wroclaw, Poland. Electronic address: henryk.kasprzak@pwr.wroc.pl.
authors.forename: Henryk
authors.initials: H
authors.lastname: Kasprzaz
authors.affiliation: Computer Science Institute, The University of Silesia in Katowice, Bedzinska 39, 41200 Sosnowiec, Poland. Electronic address: zygmunt.wrobel@us.edu.pl.
authors.forename: Zygmunt
authors.initials: Z
authors.lastname: Wróbel
mesh_terms: D000328:Adult; D000368:Aged; D000869:Anterior Eye Segment / Q000033:anatomy & histology*; D006801:Humans; D008875:Middle Aged; D041623:Tomography, Optical Coherence / Q000379:methods*
keywords: Automatic image processing; Correction; Dynamic changes; OCT; Ocular dynamics