title: Spectral optical coherence tomography vs. fluorescein pattern for rigid gas-permeable lens fit.
abstract: BACKGROUND
  This study aimed to evaluate anterior segment spectral optical coherence tomography (AS SOCT) for assessing the lens-to-cornea fit of rigid gas-permeable (RGP) lenses. The results were verified with the fluorescein pattern method, considered the criterion standard for RGP lens alignment evaluations.
  
  
  METHODS
  Twenty-six eyes of 14 patients were enrolled in the study. Initial base curve radius (BCR) of each RGP lens was determined on the basis of keratometry readings. The fluorescein pattern and AS SOCT tomograms were evaluated, starting with an alignment fit, and subsequently, with BCR reductions in increments of 0.1 mm, up to 3 consecutive changes. AS SOCT examination was performed with the use of RTVue (Optovue, California, USA).
  
  
  RESULTS
  The average BCR for alignment fits, defined according to the fluorescein pattern, was 7.8 mm (SD=0.26). Repeatability of the measurements was 18.2%. BCR reductions of 0.1, 0.2, and 0.3 mm resulted in average apical clearances detected with AS SOCT of 12.38 (SD=9.91, p<0.05), 28.79 (SD=15.39, p<0.05), and 33.25 (SD=10.60, p>0.05), respectively.
  
  
  CONCLUSIONS
  BCR steepening of 0.1 mm or more led to measurable changes in lens-to-cornea fits. Although AS SOCT represents a new method of assessing lens-to-cornea fit, apical clearance detection with current commercial technology showed lower sensitivity than the fluorescein pattern assessment.
authors.affiliation: Department of Ophthalmology, Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland.
authors.forename: Ilona
authors.initials: I
authors.lastname: Piotrowiak
authors.affiliation: Department of Ophthalmology, Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland.
authors.forename: Bartłomiej Jan
authors.initials: BJ
authors.lastname: Kaluzny
authors.affiliation: Department of Ophthalmology, Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland.
authors.forename: Beata
authors.initials: B
authors.lastname: Danek
authors.affiliation: Department of Ophthalmology, Dr. Władysław Biegański Regional Specialist Hospital, Grudziądz, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Chwiędacz
authors.affiliation: Department of Ophthalmology, Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland.
authors.forename: Bartosz Lukasz
authors.initials: BL
authors.lastname: Sikorski
authors.affiliation: Department of Ophthalmology, Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland.
authors.forename: Grażyna
authors.initials: G
authors.lastname: Malukiewicz
mesh_terms: D000328:Adult; D000869:Anterior Eye Segment / Q000033:anatomy & histology; D003261:Contact Lenses; D005260:Female; D019793:Fluorescein / Q000378:metabolism*; D005740:Gases / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010539:Permeability; D041623:Tomography, Optical Coherence / Q000379:methods*; D055815:Young Adult
chemical_list: D005740:Gases; D019793:Fluorescein