Should men taking a daily prostate pill get their eyes checked?
Yes, and this study is the reason. Men who took tadalafil for urinary symptoms had about a 22% higher risk of developing glaucoma over five years than men who took no drug in that class. In absolute terms, 3.93% of tadalafil users developed glaucoma versus 3.16% of non-users.
That works out to about 8 extra cases of glaucoma for every 1,000 men treated over five years. Put another way, roughly 130 men would need to take tadalafil for five years for one extra case of glaucoma to appear. The tadalafil glaucoma risk here is real but small, and it does not mean the drug is dangerous. It means the eyes deserve a look.
Tadalafil is best known as Cialis. Beyond erectile dysfunction, it is prescribed daily for lower urinary tract symptoms, the weak stream, urgency, and nighttime trips to the bathroom that come with an enlarging prostate. It works by relaxing smooth muscle and widening blood vessels. Those same vessel effects do not stop at the prostate. They reach the eye, which is where this question comes from.
What the data show
Researchers used TriNetX, a large multinational database of electronic health records. They looked at men aged 40 and older with a history of lower urinary tract symptoms who entered the database between 2012 and 2022. Anyone with glaucoma before joining the study was excluded. After matching, the analysis compared 36,927 tadalafil users against 36,927 men who took no PDE5 inhibitor.
Over five years, glaucoma of any kind was 22% more common in the tadalafil group (hazard ratio 1.22). The true increase is very likely somewhere between 12% and 33% (95% CI 1.12 to 1.33). The gap in cumulative incidence, 3.93% versus 3.16%, had less than a 1 in 1,000 chance of being a coincidence (p<0.001).
Three related outcomes moved in the same direction. Ocular hypertension, meaning raised pressure inside the eye before any nerve damage shows up, was about 32% more common (HR 1.32, very likely between 6% and 65% higher). Primary open-angle glaucoma, the slow and painless form that damages the optic nerve, was about 33% more common (HR 1.33, likely between 5% and 67% higher). Starting glaucoma treatment, usually pressure-lowering eye drops, was also about 33% more common (HR 1.33, very likely between 20% and 47% higher).
Two forms did not budge. Low-tension glaucoma and primary angle-closure glaucoma showed no significant link to tadalafil.
How strong is the evidence?
This is an observational study, not a trial. Nobody was randomly assigned to tadalafil, so the two groups could differ in ways the records do not capture. The researchers did the standard work to narrow that gap, matching men one to one on age, race, other conditions, kidney function, and other medications they were taking.
Two features make the signal harder to dismiss. The pattern held up in men over 50, in the white population, and across different combinations of other health conditions. It also survived lag times of one, three, and six months, an analysis that ignores the earliest cases so that glaucoma already brewing at the start does not get blamed on the drug.
The consistency across four separate eye outcomes matters too. Pressure, nerve damage, and the decision to start drops all shifted together, which is what you would expect if something real is happening rather than noise.
Dr. Kumar’s Take
The clinical move here is not stopping tadalafil. It is adding an eye exam. A 0.77 percentage point difference over five years is a small absolute change, and for a man whose sleep is wrecked by getting up four times a night, tadalafil can be worth far more than that. The authors say the same thing: this does not contraindicate the drug.
What I would change is the follow-up. If a man is starting daily tadalafil and expects to stay on it for years, a baseline eye exam with a pressure check is cheap, fast, and gives you something to compare against later. That matters most for men who already carry glaucoma risk: existing ocular hypertension, high myopia, or a parent or sibling with glaucoma.
The most useful number in this paper may be the 33% higher rate of starting glaucoma treatment. That is not a code buried in a chart. That is a doctor looking at an eye and deciding it needed medication.
Open-angle glaucoma is painless until vision is already gone, and the vision it takes does not come back. That asymmetry is what makes screening worth it here. A small risk of an irreversible problem is treated differently than a small risk of a reversible one.
Practical Takeaways
- If you are starting daily tadalafil for prostate or urinary symptoms and expect to take it long term, ask for a baseline eye exam that includes an eye pressure check before you begin.
- Tell your eye doctor you are on tadalafil, since PDE5 inhibitors are easy to leave off a medication list when they were prescribed by a urologist.
- Push harder for that exam if you already have ocular hypertension, high myopia, or a close family member with glaucoma, because those risks stack.
- Do not stop tadalafil on your own over this study, since the absolute increase is under 1 percentage point over five years and the urinary benefit may well be worth it.
Related Studies and Research
- Long daytime naps linked to higher death risk in older adults
- A plant-based diet lowered heart disease risk over 20 years
- A gentle Chinese exercise lowers blood pressure as well as brisk walking
- PPIs cause low magnesium: meta-analysis reveals 43% higher risk
FAQs
Does this apply to sildenafil (Viagra) too?
This study compared tadalafil users against men who took no PDE5 inhibitor at all, so it cannot tell you whether other drugs in the class behave the same way. Tadalafil is the one most often taken every day for urinary symptoms, which is why it was the drug studied. Sildenafil is usually taken as needed rather than daily, and daily exposure over years is the pattern this analysis was built to measure. If you take another PDE5 inhibitor regularly, the sensible response is the same conversation with your doctor, not a different conclusion drawn from this data.
What does an eye exam for glaucoma actually involve?
The core measurement is intraocular pressure, the pressure inside the eyeball, taken with a quick instrument that touches or puffs air at the surface of the eye. Your ophthalmologist will also look at the optic nerve at the back of the eye for the thinning that glaucoma causes, and may run a visual field test where you click a button each time you see a light appear at the edge of your vision. None of it hurts and the whole visit is usually under an hour. Because open-angle glaucoma gives no warning symptoms, this exam is the only way to catch it early.
If tadalafil raises eye pressure, should I stop taking it?
Not on the strength of this study alone. The absolute difference was 0.77 percentage points spread over five years, which is a small change for a drug that can meaningfully improve daily life for men with obstructive urinary symptoms. The authors did not recommend against prescribing tadalafil, they recommended watching the eyes of men who take it. If a baseline exam shows your eye pressure is already high, that is the point at which you and your doctor weigh alternatives, and that decision belongs in a clinic rather than in a headline.
Bottom Line
In a matched comparison of nearly 74,000 men with urinary symptoms, five years of tadalafil came with a 22% higher risk of glaucoma, about 8 extra cases per 1,000 men treated. The same pattern showed up in eye pressure, optic nerve damage, and the decision to start glaucoma drops. That is a small risk attached to a serious, irreversible outcome, which is exactly the situation where a cheap baseline eye exam earns its keep. Take the drug if it helps your symptoms. Get your eyes checked while you do.
