Findings from a recent study presented at the Association for Research in Vision and Ophthalmology (ARVO) 2025 Annual Meeting assessed the link between oral contraceptive pill (OCP) use and retinal layer thickness.
Give me some background.
Currently, three types of OCPs are broadly prescribed:
- Combined estrogen-progesterone
- Progesterone-only
- Continuous or extended-use pills
Additionally: In the United States, approximately 25% of women aged 15-44 who use contraception reported using OCPs as their method of choice.
- The most commonly-prescribed OCP: a combined estrogen-progesterone pill.
Go on …
Previous studies have identified estrogen and progesterone receptors in select eye tissues (see below), which may contribute to common ocular disorders, such as:
- Choroid and retina
- Age-related macular degeneration (AMD)
- Central serous chorioretinopathy (CSCR)
- Lens
- Cataracts
- Cornea
- Changes in corneal thickness, curvature, and sensitivity
- Dry eye disease (DED)
- Lacrimal and meibomian glands
- DED
All in all: Given that OCPs typically contain estrogen and progesterone, a research team from the United Kingdom (UK) hypothesized that there may be an association between OCP use and morphological changes in the retina and choroid.
Now this study.
In this retrospective study, investigators used the UK Biobank to analyze the data of healthy premenopausal women who did and did not use OCPs.
- The key measurement: Retinal layer thickness calculated from optical coherence tomography (OCT) imaging.
OCT measurements were extracted with an automatic boundary segmentation tool, including:
- Total retinal thickness (TRT)
- Inner retinal thickness (IRT)
- Measured from the internal limiting membrane to the inner nuclear-outer plexiform interface
- Outer retinal thickness (ORT)
- Measured from the inner nuclear-outer plexiform interface to Bruch’s membrane
Analyses were adjusted for potential confounding factors, such as:
- Age
- Socioeconomic status
- Smoking status
- Body mass index (BMI)
Tell me more about the study cohort.
The research team excluded patients with the following characteristics from the analysis:
- Postmenopausal women
- Women uncertain of their menopausal status
- Individuals who had undergone hysterectomy
- Premenopausal women who were within 1 year of childbirth
- Those with irregular menstrual cycles or cycles lasting longer than 36 days or shorter than 21 days
- Participants with the following systemic or conditions:
- Diabetes mellitus
- Hypertension
- Neurodegenerative disorders
- Glaucoma
- Cataracts
- Macular disease
Next up: the findings.
Data from 2,474 women (mean age: 45 years) were analyzed and organized into two cohorts:
- Non-OCP group: 2,278 participants (3,692 eyes)
- OCP group: 196 participants (318 eyes)
- Median duration of OCP use: 26 years
After adjusting for confounders, TRT was reported to be thinner in the OCP group (-8.14 μm, 95% confidence interval [CI]: -14.11 to -2.18, p = 0.01) compared to the non-OCP group.
What else?
A significant reduction in ORT was observed in the OCP user group (-6.49 μm, 95% CI: -12.47 to -0.51, p = 0.03).
- However: IRT showed no significant difference between the OCP and non-OCP groups (p = 0.85).
In addition: OCP users with a longer duration of use than the median (i.e., 26 years) showed the most significant thinning of TRT (-9.05 μm, 95% CI: -16.89 to -1.22, p = 0.03)
- Though: The difference was not significant for ORT (p = 0.12).
Take home.
These findings demonstrate an association between OCP use and retinal thickness wherein TRT was reduced in women using OCPs, and this was mediated by duration of OCP use.
Moreover: There was a reduced ORT in the OCP group—but this was not associated with use duration.
As such: These results warrant further investigation to elucidate the clinical significance and potential implications of OCP use for women’s ocular health.