“PERSIAN Eye Cohort Study (PECS): Design, Methodology”

Abstract

Abstract Purpose: To report the study protocol, methodology and latest enrollment data of a large epidemiological multi-central eye cohort named PERSIAN Eye Cohort Study (PECS) originated from the ongoing PERSIAN Cohort Study, to investigate the distribution of ophthalmic disorders in different regions and ethnicities of Iran, and determine their associations with various exposures of ophthalmic and non-ophthalmic nature. Methods: A central committee designed the study and equipped 6 chosen centers (Khameneh, Some’e Sara, Hoveizeh, Yazd, Rafsanjan and Zahedan), a focal point in each center supervised and managed conduction of the study and the data gathering under close supervision of the central committee. Results: This ongoing study launched in 2015. Out of 65,580 eligible participants of 6 centers of the PERSIAN Cohort, 48,618 individuals aged 35-70 have been enrolled in the PECS (response rate: 74.13%) until September 2021. Slit lamp and fundus photography were performed for 28,702 (59.03%) and 27,437 (56.43%) individuals, respectively. The number of participants who were referred for ophthalmology visit was 12,884, of whom, 6,885 completed the ophthalmology visit (response rate: 53.44%). Conclusion: This large epidemiological multi-central eye cohort can improve our epidemiological knowledge of prevalent ophthalmic disorders in different regions and ethnicities of Iran, and determine their associations with various exposures of ophthalmic and non-ophthalmic nature. This will be very useful for future planned nationwide and global interventions.