title: Data extraction and reporting strategies of studies assessing non-central corneal thickness by Pentacam: a review.
abstract: OBJECTIVE
  To review data extraction strategies for the reporting of non-central corneal thickness with the Pentacam system.
  
  
  METHODS
  Using predefined search terms, the electronic National Institutes of Health database (PubMed) was searched for studies assessing non-central corneal thickness using the Pentacam instrument. The article titles of the search results were screened for relevance. The abstracts of papers with appropriate titles were retrieved and read. Articles with relevant abstracts were obtained and read in full. The reference list of each article was hand searched to identify further studies. Articles reporting central corneal thickness only were excluded.
  
  
  RESULTS
  Seventeen peer-reviewed studies were identified. Considerable differences in data extraction and reporting of non-central corneal thickness were noted, with non-central pachymetry being assessed at locations between 1.5 and 5.0mm away from the centre. The terminology used to describe non-central pachymetry was inconsistent. Ring-averaged and single point pachymetry data have been reported. Ring-averaged pachymetry may obscure considerable regional variability in corneal thickness.
  
  
  CONCLUSIONS
  The use of different data extraction and reporting strategies can obscure regional corneal thickness asymmetries. This may influence the monitoring of corneal crosslinking outcomes, the interpretation of corneal swelling in contact lens studies and the clinical decision-making in preoperative assessments of refractive surgery patients. For the reliable identification of regional corneal thickness variations point-pachymetry data appears to be preferable over ring-averaged pachymetry.
authors.affiliation: Vision Sciences, Department of Life Sciences, Glasgow Caledonian University, UK; Anterior Eye Research Group, Institute for Applied Health Research, Glasgow Caledonian University, UK. Electronic address: sven.jonuscheit@gcu.ac.uk.
authors.forename: Sven
authors.initials: S
authors.lastname: Jonuscheit
mesh_terms: D003315:Cornea / Q000166:cytology*; D003941:Diagnostic Techniques, Ophthalmological; D001330:Electronic Data Processing / Q000379:methods*; D006801:Humans; D015203:Reproducibility of Results
keywords: Data extraction; Non-central corneal thickness; Pentacam; Peripheral corneal thickness