title: Distribution of intraocular pressure, central corneal thickness and vertical cup-to-disc ratio in a healthy Iranian population: the Yazd Eye Study.
abstract: OBJECTIVE
  To determine the distribution of intraocular pressure (IOP), central corneal thickness (CCT) and vertical cup-to-disc ratio (VCDR) in the healthy Iranian population.
  
  
  METHODS
  This population-based, epidemiologic study evaluated Iranian aged 40-80 years, residing in Yazd, Iran, in 2010-2011. Eligible subjects were selected by cluster random sampling. Each participant underwent an interview and ophthalmologic examination including slit lamp examination, Goldmann applanation tonometry, binocular optic disc evaluation, stereoscopic fundus photography, ultrasonic pachymetry and visual field testing.
  
  
  RESULTS
  Of 2320 eligible individuals, 2098 subjects (response rate of 90.4%) participated in the study. One eye from 1159 subjects (total of 2262 normal eyes) were randomly selected for the purpose of the study. Mean age was 53.1 ± 9.6 years. Mean IOP, CCT and VCDR were 14.2 ± 2.5 mmHg, 543 ± 37 μm and 0.32 ± 0.14, respectively. Multiple regression analysis showed a significant correlation between IOP and age (regression coefficient = 0.02 per year, p = 0.015), CCT (regression coefficient = 0.02 per micron, p < 0.001), Spherical equivalent (regression coefficient = -0.15 per dioptre, p = 0.0.024) and smoking (regression coefficient = 0.89 higher for smokers, p = 0.009); it also showed a significant correlation between CCT with spherical equivalent (regression coefficient = 3.6 per dioptre, p = 0.002) and IOP (regression coefficient = 3.6 per mmHG, p < 0.001). There was no significant correlation with VCDR.
  
  
  CONCLUSIONS
  Mean IOP, CCT and VCDR were 14.2 ± 2.5 mmHg, 543 ± 35 μm and 0.32 ± 0.14, respectively, in healthy Iranians that is different from other ethnicities. It seems advisable to pay attention to ethnicity for interpretation of each person's variables.
authors: Ophthalmic Epidemiology and Prevention of Blindness Center, Shahid Beheshti University of Medical Science, Tehran, Iran.
authors: Mohammad
authors: M
authors: Pakravan
authors: Ophthalmic Epidemiology and Prevention of Blindness Center, Shahid Beheshti University of Medical Science, Tehran, Iran.
authors: Mohammad Ali
authors: MA
authors: Javadi
authors: Ophthalmic Epidemiology and Prevention of Blindness Center, Shahid Beheshti University of Medical Science, Tehran, Iran.
authors: Shahin
authors: S
authors: Yazdani
authors: Ophthalmic Epidemiology and Prevention of Blindness Center, Shahid Beheshti University of Medical Science, Tehran, Iran.
authors: Elham
authors: E
authors: Ghahari
authors: Ophthalmic Epidemiology and Prevention of Blindness Center, Shahid Beheshti University of Medical Science, Tehran, Iran.
authors: Zohreh
authors: Z
authors: Behroozi
authors: Shahid Sadooghi University of Medical Sciences, Yazd, Iran.
authors: Reza
authors: R
authors: Soleimanizad
authors: Department of Ophthalmology and Eye Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors: Sasan
authors: S
authors: Moghimi
authors: Department of Ophthalmology and Eye Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors: Naveed
authors: N
authors: Nilforoushan
authors: Department of Ophthalmology and Eye Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors: Reza
authors: R
authors: Zarei
authors: Department of Ophthalmology and Eye Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors: Yadollah
authors: Y
authors: Eslami
authors: Ophthalmic Epidemiology and Prevention of Blindness Center, Shahid Beheshti University of Medical Science, Tehran, Iran.
authors: Mahmood
authors: M
authors: Ghassami
authors: Ophthalmic Epidemiology and Prevention of Blindness Center, Shahid Beheshti University of Medical Science, Tehran, Iran.
authors: Hossein
authors: H
authors: Ziaei
authors: Ophthalmic Epidemiology and Prevention of Blindness Center, Shahid Beheshti University of Medical Science, Tehran, Iran.
authors: Marzieh
authors: M
authors: Katibeh
authors: Ophthalmic Epidemiology and Prevention of Blindness Center, Shahid Beheshti University of Medical Science, Tehran, Iran.
authors: Hanif
authors: H
authors: Tabesh
authors: Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors: Mehdi
authors: M
authors: Yaseri
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003315:Cornea / Q000000981:diagnostic imaging*; D003430:Cross-Sectional Studies; D005260:Female; D005901:Glaucoma / Q000453:epidemiology* / Q000503:physiopathology; D006068:Gonioscopy; D006801:Humans; D015994:Incidence; D007429:Intraocular Pressure / Q000502:physiology*; D007492:Iran / Q000453:epidemiology; D008297:Male; D033401:Microscopy, Acoustic; D008875:Middle Aged; D009898:Optic Disk / Q000000981:diagnostic imaging*; D012016:Reference Values; D012189:Retrospective Studies; D012307:Risk Factors
keywords: central corneal thickness; healthy normal; intraocular pressure; vertical cup-to-disc ratio