Comparison of ocular biometrics between diabetic and non-diabetic adults: a population-based study

Abstract

Abstract This study aimed to compare ocular biometrics between diabetic and non-diabetic individuals. Understanding these biometric differences may inform cataract surgery planning and glaucoma risk assessment in diabetic patients. Participants were drawn from the second phase of the Shahroud Eye Cohort Study. Diabetes mellitus was diagnosed based on fasting blood sugar (FBS) levels of ≥ 6.99 mmol/L, HbA1c levels of ≥ 6.5%, or the use of hypoglycemic medications. Ocular biometrics were recorded using a Lenstar optical biometer. Differences in ocular biometrics between participants with and without diabetes were analyzed using t-tests and linear regression models. Among the 4452 participants, aged 45–69 years. Axial Length (AL) (Mean Difference (MD) = − 0.09 mm, 95% CI − 0.16 to -0.03), Corneal Diameter (CD) (MD = − 0.10 mm, 95% CI − 0.13 to − 0.07), Aqueous depth (AD) (MD = − 0.03 mm, 95% CI − 0.06 to − 0.01), were higher in non-diabetics, while central corneal thickness (CCT) (MD = 5.90 μm, 95% CI 3.70 to 8.10), and lens thickness (LT) (MD = 0.06 mm, 95% CI 0.03 to 0.08) were thicker in diabetics. In the multiple linear regression model, AL, AD, and CD were negatively associated with diabetes, while LT and CCT was positively associated with diabetes. In conclusion, among ocular biometrics, diabetic individuals had thicker lens and central corneas, while AL, AD, and CD were lower. Other ocular biometrics did not differ significantly in diabetics than non-diabetics. While the observed differences are statistically significant, their clinical relevance is minimal due to small effect sizes.