Hormonal Contraception and Retinal Vascular Occlusion Risk

Area of Science:

• Ophthalmology
• Cardiovascular Health
• Reproductive Health

Background:

• Retinal vascular occlusions (RVOs) are serious eye conditions that can lead to vision loss.
• Hormonal contraceptives (HCs) are widely used by women of reproductive age.
• Understanding the potential risks associated with HC use is crucial for patient counseling and public health.

Purpose of the Study:

• To investigate the association between hormonal contraceptive use and the risk of retinal vascular occlusions (retinal vein occlusion and retinal artery occlusion) in women.
• To analyze the impact of different types, dosages, and durations of HC use on RVO risk.

Main Methods:

• A nationwide, register-based cohort study followed 2,208,172 women aged 15-49 years.
• Data on HC use (prescription records) and RVO events (hospital diagnoses) were collected from January 1, 1996, to June 30, 2021.
• Poisson regression models were used to estimate incidence rate ratios, adjusting for relevant covariates.

Main Results:

• Current HC use was associated with a 40% increased rate of retinal vein occlusion (AIRR 1.4) compared to non-use.
• Combined oral contraceptives (COCs) containing 30-40 µg estrogen showed a higher risk (AIRR 1.6), while low-dose 20 µg COCs and hormonal intrauterine devices did not show an increased risk.
• No significant increase in the rate of retinal artery occlusion was observed with current HC use (AIRR 1.2).

Conclusions:

• Combined oral contraceptives containing 30-40 µg estrogen are associated with an increased rate of retinal vein occlusion.
• The absolute increase in RVO risk associated with HC use is low.
• Hormonal contraceptives do not appear to increase the risk of retinal artery occlusions.