Normal Aging Contributes to Half of RNFL Thickness Thinning in Patients with OAG, Study Finds

The median RNFL thickness slope in glaucoma patients within normal limits was significantly lower than that in healthy subjects within normal limits. Photo: Danica J. Marrelli, OD. Click image to enlarge. Optometrists and ophthalmologists routinely track changes in retinal nerve fiber layer (RNFL) thickness in glaucoma patients and suspects. However, progressive, age-related decrease in peripapillary RNFL thickness can confound assessment of glaucomatous progression. At ARVO 2025, researchers from Halifax, Canada, reported findings from a cohort of glaucoma patients and healthy control subjects followed prospectively for a mean of over 10 years to determine the proportion of progressive RNFL thickness change that can be attributed to normal aging. They determined that normal aging contributed around one-half of the RNFL thickness thinning observed in treated glaucoma patients.The study included patients treated for open-angle glaucoma and healthy subjects were followed with OCT every six months. It assessed one eye each of 200 glaucoma patients and 73 healthy controls. The median age and follow-up of all participants were 68.3 years and 10.1 years, respectively. A 12º circular scan pattern containing 768 A-scans, averaged 100 times, was used to derive mean RNFL thickness. Individual rates of RNFL thickness change with ordinary least squares regression were analyzed as a function of baseline RNFL thickness as well as baseline classification.The median RNFL thickness slope in glaucoma patients within normal limits (39, 19.5%) was -0.76µm/year, significantly lower than that in healthy subjects within normal limits (68, 93.2%, -0.51µm/year). There were no significant differences in RNFL thickness slope between the two groups in the borderline and outside normal limits baseline classifications. The researchers’ linear mixed-effects model showed a statistically significant negative RNFL thickness slope in healthy subjects (-0.54μm/year). After adjusting for covariates, diagnosis of glaucoma contributed an additional -0.47μm/year. Baseline global RNFL thickness also had a significant negative effect on RNFL thickness slope (-0.01µm/year) while baseline age had a significant positive effect on RNFL thickness slope (0.01μm/year).The researchers noted that “The RNFL thickness slope was shallower with thinner baseline RNFL thickness and higher baseline age.”Original abstract content ©2025 Association for Research in Vision and Ophthalmology. Matsuo M, Sharpe GP, Hutchinson DM, et al. Impact of normal aging on progressive thinning of the retinal nerve fibre layer in glaucoma. ARVO 2025 annual meeting.