title: Normative spectral domain optical coherence tomography data on macular and retinal nerve fiber layer thickness in Indians.
abstract: OBJECTIVE
  To provide the normative data of macular and retinal nerve fiber layer (RNFL) thickness in Indians using spectral domain OCT (Spectralis OCT, Heidelberg Engineering, Germany) and to evaluate the effects of age, gender, and refraction on these parameters.
  
  
  METHODS
  Observational, cross-sectional study.
  
  
  METHODS
  The eyes of 105 healthy patients aged between 20-75 years, with no ocular disease and best corrected visual acuity of 20/20, were scanned using standard scanning protocols by a single examiner. Exclusion criteria included glaucoma, retinal diseases, diabetes, history of prior intraocular surgery or laser treatment. The mean macular and RNFL thickness were recorded, and the effects of age, gender, and refraction on these parameters were evaluated. This data was compared with published literature on Caucasians to assess the ethnic variations of these parameters.
  
  
  RESULTS
  The normal central foveal thickness in healthy Indian eyes measured using Spectralis OCT was 260.1 ± 18.19 ΅m. The nasal inner quadrant showed maximum retinal thickness (338.88 ± 18.17 ΅m).The mean RNFL thickness was 101.43 ± 8.63 ΅m with maximum thickness in the inferior quadrant. The central foveal thickness showed a gender-based difference (P = 0.005) but did not correlate significantly with age (P = 0.134), whereas the parafoveal, perifoveal thickness, macular volume, and RNFL thickness showed significant negative correlation with age.
  
  
  CONCLUSIONS
  Our study provides the normative database for Indians on Spectralis OCT. It also suggests that age should be considered while interpreting the macular thickness and RNFL, whereas gender should also be given consideration in central foveal thickness.
authors.forename: Bindu
authors.initials: B
authors.lastname: Appukuttan
authors.forename: Anantharaman
authors.initials: A
authors.lastname: Giridhar
authors.affiliation: Department of Vitreoretinal Services, Giridhar Eye Institute, Ponneth Temple Road, Kadavanthra, Cochin, Kerala, India.
authors.forename: Mahesh
authors.initials: M
authors.lastname: Gopalakrishnan
authors.forename: Sobha
authors.initials: S
authors.lastname: Sivaprasad
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008266:Macula Lutea / Q000166:cytology*; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers; D009898:Optic Disk / Q000166:cytology*; D011446:Prospective Studies; D012016:Reference Values; D015203:Reproducibility of Results; D012165:Retinal Ganglion Cells / Q000166:cytology*; D041623:Tomography, Optical Coherence / Q000379:methods*; D055815:Young Adult