Abstract
Purpose :
Thinning of the retinal nerve fibre layer (RNFL) is an essential parameter in the detection of glaucomatous optic neuropathy but needs to be differentiated from normal, age-related loss.
Previous longitudinal reports on normal populations have been limited in their number and duration of study. The aim of this study was to compare peripapillary RNFL thickness loss, over 10 years, by age decade in a UK population. The design was a retrospective, longitudinal, study.
Methods :
The right eyes of 100 subjects (63 female / 37 male), divided into four age decades (25 subjects each), were followed for 10 years to measure peripapillary RNFL thickness change using optical coherence tomography (OCT). Subjects were defined as normal if, during the period of study, they had a visual acuity of 6/9 or better, IOP less than 22 mmHg, no losses on visual fields, and no ocular abnormality. Analysis of variance was applied to compare change in the average peripapillary RNFL thickness, as well as in the superior and inferior quadrants, over a decade between each age group. In addition, Pearson’s correlation was used for the relationship between age and rate of RNFL thickness loss.
Results :
Mean age ± standard deviation for the four groups at their last study visit were: 54.7 ± 2.8 years; 63.8 ± 2.6 years; 75.9 ± 2.9 years; and 83.7 ± 2.9 years. Changes in average RNFL thickness for the respective age groups were: -0.36 ± 0.23 µm/year; -0.37 ± 2.4 µm/year; -0.59 ± 0.45 µm/year; and -0.58 ± 0.37 µm/year (p = 0.01). Changes in superior RNFL thickness for the respective age groups were: -0.41 ± 0.40 µm/year; -0.40 ± 0.44 µm/year; -0.78 ± 0.79 µm/year; and -0.96 ± 0.85 µm/year (p < 0.01). Changes in inferior RNFL thickness for the respective age groups were: -0.65 ± 0.46 µm/year; -0.53 ± 0.43 µm/year; -0.84 ± 0.66 µm/year; and -0.90 ± 0.97 µm/year (p = 0.17). Across all subjects, the increase in annual RNFL loss per decade was: 0.09 µm / year for average peripapillary RNFL thickness (r = 0.30); 0.22 µm / year for superior RNFL thickness (r = 0.36); and 0.10 µm / year for inferior RNFL thickness (r = 0.17).
Conclusions :
The results provide evidence that peripapillary RNFL age-related loss, measured by OCT, in a normal population is not constant over time but increases with age. Furthermore, the study suggests the rate of change in the superior quadrant of RNFL thickness with age is greater than that of the inferior quadrant.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.