Men taking tadalafil, widely known by the brand name Cialis, may have a significantly increased risk of developing glaucoma, a serious eye condition, a recent study indicates. Researchers found that patients on tadalafil were up to 33% more likely to develop the most common form of glaucoma and 32% more likely to experience ocular hypertension, a condition characterized by high pressure inside the eye that can lead to glaucoma.
Glaucoma damages the optic nerve, which connects the eye to the brain, and is a leading cause of preventable blindness worldwide. In the UK, it affects approximately one million people and accounts for about 10% of blindness.
The observational study, conducted by scientists in Taiwan and the US, analyzed data from over 73,000 men aged 40 and older. Half of the participants had been prescribed tadalafil or a similar erectile dysfunction medication for up to five years. The findings revealed a correlation between tadalafil use and a 22% increased likelihood of developing glaucoma compared to non-users.
While the study cannot definitively prove causation, researchers theorize that long-term tadalafil use might lead to temporary increases in eye pressure or reduce blood flow to the optic nerve, potentially contributing to the condition. These theories, however, require further investigation. Tadalafil is also prescribed for enlarged prostate symptoms, and its known side effects include headaches, which can also be a warning sign of glaucoma.
Erectile dysfunction affects millions of men globally, with tadalafil being a commonly prescribed treatment. The drug functions by increasing blood flow to the penis, aiding in achieving and maintaining an erection. For enlarged prostates, it works by relaxing muscles in the prostate and bladder.
These findings emerge as projections indicate a rise in glaucoma cases in the coming decades. One earlier study suggested that by 2060, 1.6 million people in the UK could be living with the condition, a 60% increase from current numbers. This rise is attributed to an aging population and growth in ethnically diverse communities, which are often at higher risk.
The National Health Service (NHS) notes that many individuals are unaware they have glaucoma due to its slow development and often subtle symptoms. While headaches and nausea might be dismissed, more severe signs include intense eye pain, redness or tenderness of the eyes, blurred vision, and seeing rainbow-colored halos around lights.