title: Precise measurement of scleral radius using anterior eye profilometry.
abstract: OBJECTIVE
  To develop a new and precise methodology to measure the scleral radius based on anterior eye surface.
  
  
  METHODS
  Eye Surface Profiler (ESP, Eaglet-Eye, Netherlands) was used to acquire the anterior eye surface of 23 emmetropic subjects aged 28.1±6.6years (mean±standard deviation) ranging from 20 to 45. Scleral radius was obtained based on the approximation of the topographical scleral data to a sphere using least squares fitting and considering the axial length as a reference point. To better understand the role of scleral radius in ocular biometry, measurements of corneal radius, central corneal thickness, anterior chamber depth and white-to-white corneal diameter were acquired with IOLMaster 700 (Carl Zeiss Meditec AG, Jena, Germany).
  
  
  RESULTS
  The estimated scleral radius (11.2±0.3mm) was shown to be highly precise with a coefficient of variation of 0.4%. A statistically significant correlation between axial length and scleral radius (R2=0.957, p<0.001) was observed. Moreover, corneal radius (R2=0.420, p<0.001), anterior chamber depth (R2=0.141, p=0.039) and white-to-white corneal diameter (R2=0.146, p=0.036) have also shown statistically significant correlations with the scleral radius. Lastly, no correlation was observed comparing scleral radius to the central corneal thickness (R2=0.047, p=0.161).
  
  
  CONCLUSIONS
  Three-dimensional topography of anterior eye acquired with Eye Surface Profiler together with a given estimate of the axial length, can be used to calculate the scleral radius with high precision.
authors.affiliation: Department of Biomedical Engineering, Wroclaw University of Science and Technology, Poland. Electronic address: danilo.jesus@pwr.edu.pl.
authors.forename: Danilo A
authors.initials: DA
authors.lastname: Jesus
authors.affiliation: Department of Biomedical Engineering, Wroclaw University of Science and Technology, Poland.
authors.forename: Renata
authors.initials: R
authors.lastname: Kedzia
authors.affiliation: Department of Biomedical Engineering, Wroclaw University of Science and Technology, Poland.
authors.forename: D Robert
authors.initials: DR
authors.lastname: Iskander
mesh_terms: D000328:Adult; D000869:Anterior Eye Segment / Q000033:anatomy & histology*; D019781:Corneal Topography / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results; D012590:Sclera / Q000033:anatomy & histology*; D012680:Sensitivity and Specificity
keywords: Anterior eye topography; Fourier domain profilometer; Scleral contact lenses; Scleral curvature