Distribution of intraocular pressure, central corneal thickness and vertical cup‐to‐disc ratio in a healthy Iranian population: the Yazd Eye Study

• Published in: Acta ophthalmologica (Oxford, England) Vol. 95; no. 2; pp. e144 - e151
• Main Authors: Pakravan, Mohammad, Javadi, Mohammad Ali, Yazdani, Shahin, Ghahari, Elham, Behroozi, Zohreh, Soleimanizad, Reza, Moghimi, Sasan, Nilforoushan, Naveed, Zarei, Reza, Eslami, Yadollah, Ghassami, Mahmood, Ziaei, Hossein, Katibeh, Marzieh, Tabesh, Hanif, Yaseri, Mehdi
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.03.2017
• Subjects: Adult; Aged; Aged, 80 and over; central corneal thickness; Cornea - diagnostic imaging; Cross-Sectional Studies; Female; Glaucoma - epidemiology; Glaucoma - physiopathology; Gonioscopy; healthy normal; Humans; Incidence; intraocular pressure; Intraocular Pressure - physiology; Iran - epidemiology; Male; Microscopy, Acoustic; Middle Aged; Ophthalmology; Optic Disk - diagnostic imaging; Reference Values; Retrospective Studies; Risk Factors; vertical cup‐to‐disc ratio; intraocular pressure; healthy normal; central corneal thickness; vertical cup-to-disc ratio
• ISSN: 1755-375X; 1755-3768; 1755-3768
• DOI: 10.1111/aos.13231

Purpose 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.