Findings from a recent study published in Journal of Glaucoma indicate that female reproductive factors may be associated with the pathogenesis of open angle glaucoma (OAG).
Give me some background.
OAG is the leading cause of irreversible vision loss and blindness around the world. With more OAG incidents in men than in women, previous research suggests that women may carry factors protecting against OAG.
Also of note is increasing evidence that OAG is linked to estrogen; however, the reports on the type of correlation are mixed.
And the goal?
Study authors conducted a systematic review and dose-response analysis to measure the association of OAG with the following reproductive factors:
- Menarcheal age (age of first menstrual period)
- Menopausal age
- Reproductive period (time from menarche to menopause)
- Parity (number of births)
Now talk about the study.
This study followed Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines and Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines.
Out of 2,645 studies that were initially screened, seven articles were included in the analysis. Overall, data from 18,618 women who were at least 40 years old were included in this analysis.
And the inclusion criteria?
Studies that met the following inclusion criteria were included in the systematic review:
- Explored link between reproductive factors and OAG
- Original and observational studies
- Conducted visual field testing and optic disc assessment to diagnose OAG
- Calculated odds ratio (OR) and 95% confidence interval (CL)
Findings?
The meta-analyses found that late age at menarche (≥ 13 years) was associated with a greater risk of OAG.
An early age at menopause (≤ 45 years) was linked to an elevated risk of OAG compared to late menopause (≥ 50 years), though women with menopausal ages between 45 to 49 did not demonstrate any significant change in OAG risk.
A greater risk of OAG was only seen in women who delivered five or more babies compared to nulliparous women (women who haven’t given birth).
Reproductive periods were not associated with OAG risk.
What about the dose-response analysis?
A significant inverse linear relationship was identified between age of menopause and OAG risk.
There was also a J-shaped relationship—indicating an initial fall but eventual rise—between parity and risk of OAG. Two deliveries were associated with the lowest OAG risk.
The dose-response relationship between menarcheal age and OAG risk was unable to be tested due to a lack of eligible studies.
Any limitations?
A few … causality between reproductive factors and risk of developing OAG is difficult to explain with a retrospective, cross-sectional analysis.
Other factors included the limited number of eligible studies and potential issues with accuracy, including inaccurate self-reporting of menearcheal or menopausal age and differences in OAG diagnostic criteria (which may have led to misclassified OAG cases).
Author input?
“Our findings suggest that reproductive factors possibly play a role in glaucoma development, while higher-quality studies with longitudinal design and larger sample sizes are needed for further verification,” the study authors stated.
Take home.
Later menarcheal age, earlier menopausal age, and parity of five or more is associated with an elevated risk of developing OAG—providing support for the argument that there is a correlation between female reproductive factors and OAG.