Estrogen May Protect Against Optic Nerve Neurodegeneration

This study observed a dose-dependent relationship between age at menopause and RNFL thickness among women. Female patients who entered menopause before age 45 had an RNFL thickness of 121.0µm compared with 122.5µm in those who experienced menopause after age 50. Photo: Jarett Mazzarella, OD, and Justin Cole, OD. Click image to enlarge.  Recent research has explored the potential differences in glaucoma risk between sexes, with previous results showing variability. To investigate, a new study whose findings were presented earlier this week at ARVO 2025 in Salt Lake City focused on measuring the thickness of the peripapillary retinal nerve fiber layer (RNFL) using optical coherence tomography (OCT) in healthy adults, analyzing differences between sexes and examining the impact of the age at menopause on RNFL thickness in women. Its findings revealed that estrogen may play a protective role against optic nerve neurodegeneration, thereby lowering the risk of glaucoma in women. The study gathered data from individuals aged 50 or older of African, Chinese or Latin American descent, participating in three population-based studies. RNFL thickness and optic nerve head parameters were evaluated using the Cirrus HD-OCT 4000. Next, researchers analyzed the data to evaluate the relationship between sex, age at menopause and RNFL thickness, adjusting for factors such as disc area, scan signal strength, axial length, age, blood pressure, and HbA1c levels.The results, derived from OCT scans of 6,133 participants (11,585 eyes), indicated that men generally have a thinner RNFL than women, with significant differences persisting even after adjusting for confounders. This pattern was consistent across different ethnic groups. Notably, significant differences in RNFL thickness between sexes were found in the inferior and temporal quadrants of the eye.Another interesting observation was that of a dose-dependent relationship between the age at menopause and RNFL thickness among women, suggesting that later menopause could be associated with thicker RNFL. Specifically, female patients who entered menopause after the age of 50 exhibited an average RNFL thickness of 122.5µm, while those who experienced menopause between the ages of 45 and 49 or before age 45 had average thicknesses of 121.8µm and 121.0µm, respectively.In summary, these findings imply that estrogen may have a neuroprotective effect on the optic nerve and highlight the importance of considering sex and hormonal factors in glaucoma risk assessments and interventions.Original abstract content ©2025 Association for Research in Vision and Ophthalmology. Jiang K, Torres M, Burkemper B, Varma R. Sex differences in retinal nerve fiber layer thickness in healthy eyes across racial/ethnic groups. ARVO 2025 annual meeting.