Retinal nerve fibre layer thickness measured with <scp>SD</scp> ‐ <scp>OCT</scp> in a population‐based study of <scp>F</scp> rench elderly subjects: the <scp>A</scp> lienor study

Purpose To establish normative data of retinal nerve fibre layer (RNFL) thickness in the elderly and to determine the factors influencing its thickness. Methods Peripapillary RNFL thickness was measured with spectral domain OCT (SD-OCT) in 210 elderly participants from the Alienor population-based study who were aged 75 years or older. The measure was assessed in six segments (the superotemporal, temporal, inferotemporal, inferonasal, nasal and superonasal segments). RNFL data were analysed across age and sex strata in non-glaucoma participants. Mixed linear models were used to evaluate the associations of RNFL thickness with age, sex, ocular parameters and vascular risk factors. Results The mean global RNFL thickness was 91.4 μm (SD: 12.6), ranging from 55 to 122; the highest values were found in the inferotemporal and superotemporal segments. After adjustment for sex and ocular parameters, including axial length, increasing age was significantly associated with lower thickness globally (mean thinning per decade = 5.6 μm, p = 0.003), in the superotemporal (−12.7 μm per decade, p