Purpose: To describe GDxVCC retinal nerve fiber layer (RNFL) measures and associations in a predominantly white British population.
Methods: The EPIC-Norfolk Eye Study is nested within a large multicenter cohort study, the European Prospective Investigation of Cancer. RNFL measurements were taken using the GDxVCC. Generalized estimating equation models were used to assess associations of RNFL measures with age, sex, body mass index (BMI), height, blood pressure, social class, education level, alcohol intake, smoking status, axial length, intraocular pressure, and lens status. Models were linearly adjusted for typical scan score to handle scans with atypical retardation.
Results: There were complete data from 11,030 eyes of 6309 participants with mean age 68 years (48-90 years). Older age (-1.53 μm/decade [95% confidence interval {CI} -1.73, -1.33], P < 0.001), male sex (-0.44 μm [95% CI -0.04, -0.84], P = 0.031), shorter axial length (-0.15 μm/mm [95% CI -0.02, -0.28], P = 0.024), and pseudophakia (-0.49 μm [95% CI -0.94, -0.04], P = 0.033) were associated with thinner RNFL after adjustment for possible confounders. Higher BMI was associated with a thinner RNFL in men only (-0.30 μm/5 kg/m(2) [95% CI -0.58, -0.02], P = 0.039).
Conclusions: This analysis of associations with RNFL thickness in a largely healthy population may provide insight into the determinants of glaucoma, suggesting higher risk in those who are older, in men, and in men with a higher BMI.
Keywords: axial length; body mass index; epidemiology; eye; glaucoma; scanning laser polarimetry.