Age and Retinal Nerve Fiber Layer Thickness Measured by Spectral Domain Optical Coherence Tomography

PURPOSE To evaluate the association between age and peripapillary retinal nerve fiber layer (RNFL) thickness measured by Cirrus high-definition (HD) spectral domain optical coherence tomography (OCT) in healthy Korean subjects. METHODS A total of 302 eyes from 155 healthy Korean subjects (age range, 20 to 79 years) underwent RNFL thickness measurements using the Cirrus HD-OCT. Average, quadrant, and clock-hour RNFL thickness parameters were analyzed in terms of age using linear mixed effect models. RESULTS Average RNFL demonstrated a slope of -2.1 µm per decade of age (p < 0.001). In quadrant analysis, superior (-3.4 µm/decade, p < 0.001) and inferior (-2.9 µm/decade, p < 0.001) quadrants showed steeper slopes, whereas temporal (-1.1 µm/decade, p < 0.001) and nasal (-1.0 µm/decade, p < 0.001) quadrants revealed shallower slopes. Among the 12 clock-hour sectors, clock hours 6 (-4.5 µm/decade, p < 0.001) and 1 (-4.1 µm/decade, p < 0.001) showed the greatest tendency to decline with age; RNFLs of the 3 (-0.2 µm/decade, p = 0.391) and 4 (-0.6 µm/decade, p = 0.052) o'clock hour sectors did not show significant decay. CONCLUSIONS RNFL thickness was associated with age, especially in superior and inferior areas. The topographic distribution of correlation between age and RNFL thickness was not uniform.