Data-Driven Redefinition of Normal Intraocular Pressure in Non-Glaucomatous Korean Adult Population

Purpose: To characterize the population-based normative distribution of intraocular pressure (IOP) in Korean adults using survey-weighted data from the Korea National Health and Nutrition Examination Survey (KNHANES) 2019-2021.Design: Cross-sectional, population-based study using nationally representative data.Participants: Adults aged 19 years who completed the KNHANES ophthalmic examination during the 2019-2021 cycles.Individuals with glaucoma, missing IOP or refractive data, or implausible IOP values (<5 or >40 mmHg) were excluded. Methods:The ophthalmic examination included rebound tonometry and non-cycloplegic autorefraction using a standardized national protocol.Glaucoma status was determined through centralized expert panel review based on International Society of Geographical and Epidemiological Ophthalmology criteria.Refractive error was classified using spherical equivalent (SE): hyperopia (SE > +0.50 D), emmetropia (-0.50 to +0.50 D), mild myopia (-0.50 to -3.00 D), moderate myopia (-3.00 to -6.00 D), and high myopia (<-6.00D).Diabetes and metabolic syndrome (MetS) were defined using established clinical criteria.All analyses incorporated ophthalmic examination weights to account for differential sampling and nonresponse.Weighted mean IOP and weighted 95 th percentiles were estimated across demographic and clinical subgroups.Main Outcome Measures: Weighted mean IOP and weighted 95 th percentile for each age, sex, refractive, and metabolic subgroup.Results: A total of 10,625 non-glaucomatous adults were included.Across most age-sex strata, the weighted 95 th percentile of IOP ranged from 18.1 to 19.2 mmHg, substantially