title: A program to analyse optical coherence tomography images of the ciliary muscle.
abstract: OBJECTIVE
  To describe and validate bespoke software designed to extract morphometric data from ciliary muscle Visante Anterior Segment Optical Coherence Tomography (AS-OCT) images.
  
  
  METHODS
  Initially, to ensure the software was capable of appropriately applying tiered refractive index corrections and accurately measuring orthogonal and oblique parameters, 5 sets of custom-made rigid gas-permeable lenses aligned to simulate the sclera and ciliary muscle were imaged by the Visante AS-OCT and were analysed by the software. Human temporal ciliary muscle data from 50 participants extracted via the internal Visante AS-OCT caliper method and the software were compared. The repeatability of the software was also investigated by imaging the temporal ciliary muscle of 10 participants on 2 occasions.
  
  
  RESULTS
  The mean difference between the software and the absolute thickness measurements of the rigid gas-permeable lenses were not statistically significantly different from 0 (t=-1.458, p=0.151). Good correspondence was observed between human ciliary muscle measurements obtained by the software and the internal Visante AS-OCT calipers (maximum thickness t=-0.864, p=0.392, total length t=0.860, p=0.394). The software extracted highly repeatable ciliary muscle measurements (variability ≤6% of mean value).
  
  
  CONCLUSIONS
  The bespoke software is capable of extracting accurate and repeatable ciliary muscle measurements and is suitable for analysing large data sets.
authors.affiliation: Ophthalmic Research Group, Life & Health Sciences, Aston University, Birmingham B4 7ET, UK.
authors.forename: Deborah S
authors.initials: DS
authors.lastname: Laughton
authors.affiliation: Ophthalmic Research Group, Life & Health Sciences, Aston University, Birmingham B4 7ET, UK; Biomedical Engineering, Life & Health Sciences, Aston University, Birmingham, UK.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Coldrick
authors.affiliation: Ophthalmic Research Group, Life & Health Sciences, Aston University, Birmingham B4 7ET, UK.
authors.forename: Amy L
authors.initials: AL
authors.lastname: Sheppard
authors.affiliation: Ophthalmic Research Group, Life & Health Sciences, Aston University, Birmingham B4 7ET, UK.
authors.forename: Leon N
authors.initials: LN
authors.lastname: Davies
mesh_terms: D000328:Adult; D002924:Ciliary Body / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D009130:Muscle, Smooth / Q000033:anatomy & histology*; D015203:Reproducibility of Results; D012984:Software; D041623:Tomography, Optical Coherence
keywords: AS-OCT; Accommodation; Ciliary muscle; Presbyopia