Age-Related Physiologic Thinning Rate of the Retinal Nerve Fiber Layer in Different Levels of Myopia
Daun Jeong, Kyung Rim Sung, Youn Hye Jo, Sung‐Cheol Yun
Abstract
Purpose . To investigate the effect of refractive error on the physiologic thinning rate of the retinal nerve fiber layer (RNFL) in healthy eyes. Materials and Methods . This study analyzed 223 eyes of 141 healthy subjects followed for more than 5 years and underwent at least five serial spectral domain optical coherence tomography (SD-OCT) examinations. Longitudinal RNFL measurements were analyzed by linear mixed models incorporating follow-up duration, baseline RNFL thickness, spherical equivalent (SE), age, intraocular pressure, and visual field mean deviation. Thinning rates were classified according to SE into three groups: nonmyopic (NM; >0 D), mild-to-moderately myopic (MM; >–6 D and ≤0 D), and highly myopic (HM; ≤–6 D). Results . The overall slopes of change in RNFL thickness over time in the NM, MM, and HM groups were −0.305 ± 0.128, −0.294 ± 0.068, and −0.208 ± 0.097 μ m/yr, respectively. Slopes of RNFL thickness changes in these groups were −0.514 ± 0.248, −0.520 ± 0.133, and −0.528 ± 0.188 μ m/yr, in the superior quadrant; −0.084 ± 0.145, 0.107 ± 0.082, and −0.161 ± 0.112 μ m/yr, in the temporal quadrant; −0.807 ± 0.242, −0.794 ± 0.130, and −0.727 ± 0.183 μ m/yr, in the inferior quadrant; and 0.160 ± 0.157, 0.118 ± 0.084, and 0.429 ± 0.119 μ m/yr, in the nasal quadrant. Overall and in all four quadrants, there was no significant difference in the rate of RNFL thickness change among the three groups. Conclusions . Refractive error did not affect the physiologic thinning rate of RNFL when assessed by SD OCT.