Evaluation of age- and gender-related changes in retinal nerve fiber layer thickness in healthy adults: an optical coherence tomography study.

BACKGROUND: Retinal nerve fiber layer (RNFL) thickness varies with age and gender and serves as a reference for the diagnosis and follow-up of retinal and neurological disorders. This study aimed to provide population-specific reference data on RNFL thickness in healthy adults and to analyze its variation with age and gender. MATERIALS AND METHODS: This prospective, cross-sectional study included 320 eyes of 160 healthy participants aged 18 years or older who presented to Bolu Abant Izzet Baysal University (BAİBÜ) Education and Research Hospital and had no ocular pathology. RNFL thickness was measured using spectral-domain optical coherence tomography (OCT) (Heidelberg Engineering, Heidelberg, Germany). After participants were grouped according to age and gender, the global average (G), nasal (N), nasal superior (NS), nasal inferior (NI), temporal (T), temporal superior (TS), and temporal inferior (TI) values were recorded. Statistical analyses were performed using RStudio (version 2024.04.2, Build 764). RESULTS: Statistically significant between-group differences were found for G, NS, NI, and TI, and a significant difference between genders was found for T. Age and gender had a significant interaction effect on TS. Age-related decreases were observed in N, NS, TS, TI, and NI. CONCLUSIONS: In healthy adults, RNFL thickness decreased with age. Because these findings were obtained from a single-center sample, they may serve as preliminary normative data for the diagnosis and follow-up of retinal diseases.