Retino-Vascular changes throughout the Menstrual Cycle: Associations with retinal imaging in UK Biobank

Abstract

Purpose : The menstrual cycle involves understudied unique hormonal dynamics. In this work, we explored associations between posterior pole morphology and menstrual cycle phases in healthy eumenorrheic women from the UK Biobank on optical coherence tomography (OCT) and colour fundus photography (CFP).

Methods : 67,311 UK Biobank participants aged 40 to 69 had retinal imaging at recruitment (2006 to 2010). We extracted OCT total retinal thickness (TRT) and choroidal thickness (CHT) with a Boundary Segmentation Tool. On CFP, a deep-learning model extracted the Cup-to-disc ratio (CRD) and retinal vessel calibre (arterial and venular). Exclusions were made for poor-quality images and individuals with self-reported eye disease, reduced vision, diabetes, hypertension, and neurodegenerative disease. Women with irregular cycles, oral contraceptive use, pregnancy, or hormonal replacement therapy were excluded. In a cross-sectional analysis, we studied relationships with early follicular (menstrual), mid-follicular, and luteal phases using linear mixed-effects models, adjusted for age, socioeconomic status, smoking, and body mass index.

Results : Data from 2,817 female participants were included in this analysis. The mean age was 46 ± 4 years and the mean cycle length was 27 ± 3 days. 529 of the women were menstruating, 501 in mid-follicular and 1,787 in the luteal phase. Following adjustments for confounding variables, our analysis did not reveal any statistically significant associations. CHT, TRT and CDR exhibited a decrease in the mid-follicular phase but an increase in the luteal phase compared to the early follicular phase. Meanwhile, vessel calibre consistently followed the same direction of change in both phases (Table 1).

Conclusions : In this study, we observed no statistically significant association between CHT, TRT, CDR or retinal vessel calibre with the menstrual cycle phases, after adjusting for confounders. These findings suggest that despite hormonal fluctuations and their potential impact on vasculature, a homeostatic balance prevails, mitigating significant variations in retinal and choroidal circulation or posterior pole morphology.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.

 

Association of CHT, TRT, CDR, and Vessel Caliber with Menstrual Cycle Phases. Coefficients are presented as (Estimate, [95% Confidence Interval], p-value). The early follicular phase was established as the reference for the linear mixed-effects model.