title: Analysis of macular thickness in British population using optical coherence tomography (OCT): an emphasis on interocular symmetry.
abstract: OBJECTIVE
  To evaluate macular thickness measurements in normal subjects from British origin, to assess interocular asymmetry using optical coherence tomography (OCT) and to establish standard values for macular and foveal thickness.
  
  
  METHODS
  Two hundred eyes of 100 normal individuals underwent serial scans using fast macular thickness map protocol in the Stratus OCT version 3.51, with foveal fixation. Minimum foveal thickness (MFT), central 1 mm average foveal thickness (AFT), total foveal volume (TFV) and total macular volume (TMV at 6 mm) of both eyes were assessed. The interocular asymmetry was measured and statistically analyzed.
  
  
  RESULTS
  The mean +/- SD (N = 200) was 173 +/- 23 microm for MFT and 203 +/- 24 microm for AFT. The mean difference +/- SD between the two eyes was (3.5 +/- 14.5 microm at p = 0.17) for MFT, (6.4 +/- 14.7 microm at p = 0.06) for AFT, (0.007 mm3 +/- 0.007 at p = 0.06) for TFV and (0.19 +/- 0.35 at p = 0.07) for TMV.
  
  
  CONCLUSIONS
  Our study provides a normative database for macular thickness and volume parameters in normal British individuals using Stratus OCT. The MFT, AFT, TMV and TFV measurements were not statistically significant between the two eyes. Hence, the interocular symmetry should be considered on interpretation of macular thickness values especially in cases of uniocular or asymmetrical macular involvement.
authors.affiliation: Princess Alexandra Eye Pavilion, Edinburgh, United Kingdom. elashrymohamed@yahoo.co.uk
authors.forename: Mohamed
authors.initials: M
authors.lastname: El-Ashry
authors.forename: Vijay
authors.initials: V
authors.lastname: Hegde
authors.forename: Peter
authors.initials: P
authors.lastname: James
authors.forename: Sergio
authors.initials: S
authors.lastname: Pagliarini
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019412:Anatomy, Cross-Sectional; D001837:Body Weights and Measures; D005260:Female; D006801:Humans; D008266:Macula Lutea / Q000033:anatomy & histology*; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D041623:Tomography, Optical Coherence; D006113:United Kingdom