Increased hyperopia with ageing based on cycloplegic refractions in adults: The Tehran Eye Study

Aim: To determine the trend in the prevalence of hyperopia in Tehran, Iran. Methods: Using a stratified random cluster sample of the population of Tehran, all participants 5 years of age and older were studied with cycloplegic autorefraction 30 min after instilling two drops of cyclopentolate 1%. Prevalence rates of cycloplegic hyperopia for different cut points were determined, stratified by age. Results: The prevalence rates of hyperopia as a spherical equivalent equal to or more than +0.5, +1.0, +2.0 and +3.0 D were 56.6%, 28.1%, 6.3% and 2.2%, respectively. With all these definitions, the prevalence of cycloplegic hyperopia reached a minimum in the 25 - 35-year age group, and then significantly increased until the age of 70. Multivariable regression analysis with variables such as age, gender, diabetes and cataract showed that only age was significantly correlated with hyperopia. Conclusions: Although an age-cohort effect cannot be ruled out, these results provide the first population-based evidence of increasing hyperopia with age using cycloplegic refraction. The results obtained suggest that the contribution of decreasing accommodation to observed hyperopic shifts in distance refraction in longitudinal studies is small, raising the question of the underlying causes of the hyperopic shift in refraction with age.