Risk Factors for Uncorrected Refractive Error: Persian Cohort Eye Study - Rafsanjan Center

To determine the prevalence of visually significant uncorrected refractive error (URE) in Rafsanjan and investigate the related factors. URE is the leading cause of visual impairment (VI) which causes the second-highest number of years lived with disability. The URE is a preventable health problem.

In this cross-sectional study participants from Rafsanjan who were 35-70 years were enrolled between 2014 and 2020. Demographic and clinical characteristics data were gathered, and eye examination was performed. Visually significant URE was defined as present if habitual visual acuity was (HVA; visual acuity with present optical correction) >0.3 logMAR in the best eye and the visual acuity of that eye showed >0.2 logMAR improvement after the best correction. Logistic regression was used to determine the association between predicting variables (age, sex, wealth, education, employment, diabetes, cataract, and refractive error characteristics) and outcome (URE).

Among the 6991 participants of Rafsanjan subcohort of the Persian Eye Cohort, 311 (4.4%) had a visually significant URE. Diabetes was significantly more prevalent in the participants with visually significant URE, at 18.7% versus 13.1% in patients without significant URE (P = 0.004). In the final model, each year of increase in age was associated with 3% higher URE (95% confidence interval [CI]: 1.01-1.05). In comparison to low hyperopia, participants with low myopia had 5.17 times more odds of visually significant URE (95% CI: 3.38-7.93). However, antimetropia decreased the risk of visually significant URE (95% CI: 0.02-0.37).

Policymakers should pay special attention to elderly patients with myopia to effectively reduce the prevalence of visually significant URE.