title: Comparison of optic area measurement using fundus photography and optical coherence tomography between optic nerve head drusen and control subjects.
abstract: OBJECTIVE
  To compare optic disc area measurement between optic nerve head drusen (ONHD) and control subjects using fundus photography, time-domain optical coherence tomography (TD-OCT) and spectral-domain optical coherence tomography (SD-OCT). We also made a comparison between each of the three techniques.
  
  
  METHODS
  We performed our study on 66 eyes (66 patients) with ONHD and 70 healthy control subjects (70 controls) with colour ocular fundus photography at 20º (Zeiss FF 450 IR plus), TD-OCT (Stratus OCT) with the Fast Optic Disc protocol and SD-OCT (Cirrus OCT) with the Optic Disc Cube 200 × 200 protocol for measurement of the optic disc area. The measurements were made by two observers and in each measurement a correction of the image magnification factor was performed. Measurement comparison using the Student's t-test/Mann-Whitney U test, the intraclass correlation coefficient, Pearson/Spearman rank correlation coefficient and the Bland-Altman plot was performed in the statistical analysis.
  
  
  RESULTS
  Mean and standard deviation (SD) of the optic disc area in ONHD and in controls was 2.38 (0.54) mm(2) and 2.54 (0.42) mm(2), respectively with fundus photography; 2.01 (0.56) mm(2) and 1.66 (0.37) mm(2), respectively with TD-OCT, and 2.03 (0.49) mm(2) and 1.75 (0.38) mm(2), respectively with SD-OCT. In ONHD and controls, repeatability of optic disc area measurement was excellent with fundus photography and optical coherence tomography (TD-OCT and SD-OCT), but with a low degree of agreement between both techniques.
  
  
  CONCLUSIONS
  Optic disc area measurement is smaller in ONHD compared to healthy subjects with fundus photography, unlike time-domain and spectral-domain optical coherence tomography in which the reverse is true. Both techniques offer good repeatability, but a low degree of correlation and agreement, which means that optic disc area measurement is not interchangeable or comparable between techniques.
authors: Alcorcon Foundation University Hospital Ophthalmology Unit, Madrid, Spain. patricia.flores.r@gmail.com
authors: Patricia
authors: P
authors: Flores-Rodríguez
authors: Pablo
authors: P
authors: Gili
authors: María Dolores
authors: MD
authors: Martín-Ríos
authors: Eulalia
authors: E
authors: Grifol-Clar
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D005654:Fundus Oculi; D006801:Humans; D008297:Male; D008875:Middle Aged; D015594:Optic Disk Drusen / Q000473:pathology*; D010781:Photography / Q000379:methods*; D015203:Reproducibility of Results; D041623:Tomography, Optical Coherence / Q000379:methods*