Daily Tadalafil Linked to Higher Glaucoma Risk, Study Finds

A routine pill for prostate-related urinary troubles may carry an unexpected cost to eye health. New observational data link everyday tadalafil use to a modestly higher chance of developing glaucoma and raised intraocular pressure over several years. The signal is subtle, but for men taking the drug chronically it raises a clear clinical question: should eye checks become part of ongoing care?

Tadalafil, commonly known by the brand name Cialis, belongs to the phosphodiesterase type 5 inhibitor family. Most readers know these drugs for treating erectile dysfunction, yet they are also prescribed daily to relieve lower urinary tract symptoms from an enlarged prostate. That long-term, continual dosing is what sets tadalafil apart in safety discussions.

Why this matters to patients and clinicians

Researchers tapped the TriNetX Analytics Network and examined anonymized health records for 73,854 men aged 40 and older between 2012 and 2022. Half of the cohort received tadalafil or another PDE5 inhibitor for urinary symptoms; the other half did not. The study matched patients on age, ethnicity, smoking, cardiovascular disease, diabetes and a raft of other factors in an effort to reduce bias.

After up to five years of follow-up, tadalafil users were about 22 percent more likely to receive a glaucoma diagnosis than matched counterparts. They also had a roughly 32 percent higher chance of being diagnosed with ocular hypertension, and a similar roughly 33 percent increase in rates of primary open-angle glaucoma and initiation of glaucoma treatment. These associations appeared within months for some patients and persisted across several subgroup checks, particularly among men aged 50 and older and among White patients, who made up most of the sample.

Observational studies cannot prove cause and effect. The investigators acknowledge several important limits: prescription records do not equal confirmed long-term adherence; new health conditions arising during follow-up might have influenced outcomes; and the cohort lacked broad ethnic diversity, which weakens the ability to generalize the findings globally. Still, the pattern was consistent enough to prompt a call for more targeted research into how chronic PDE5 inhibition might alter ocular physiology.

Is there a plausible biological mechanism? Possibly. PDE5 inhibitors influence nitric oxide–cGMP signaling and vascular tone, which can affect ocular blood flow and perfusion pressure. Those changes might, in theory, interact with established risk pathways for optic nerve damage or intraocular pressure regulation. That explanation remains speculative and unproven; mechanistic studies are needed.

Clinical implications and practical steps

What should clinicians and patients take away today? The study’s authors do not argue that tadalafil should be avoided when it provides meaningful symptom relief. Instead, they recommend baseline eye assessments and periodic follow-up for men on long-term therapy—especially those with known risk factors such as a family history of glaucoma, existing ocular hypertension, high myopia, or prior optic nerve disease.

For urologists prescribing daily tadalafil for benign prostatic hyperplasia, the finding stresses cross-specialty communication. Ophthalmologists should be alerted when patients on chronic PDE5 therapy present with vision complaints or elevated eye pressure. And patients should be advised to report new visual symptoms promptly: blurred or patchy vision, loss of peripheral sight, or unusual light sensitivity.

Patients starting or continuing daily tadalafil should have a baseline eye exam and regular monitoring when long-term therapy is planned.

Expert Insight

"The magnitude of risk reported is not catastrophic, but it is meaningful enough to warrant vigilance," says Dr. Laura Mendes, an ophthalmologist specializing in glaucoma. "When a medication is taken daily for years, even modest shifts in ocular physiology can accumulate. Collaborative care—simple screening and communication between prescribers and eye specialists—will catch problems early and preserve vision."

Research priorities now include prospective studies that record actual drug exposure, standardized eye measurements, and mechanistic work in the lab to test whether PDE5 inhibition directly changes intraocular pressure or optic nerve blood flow. Those studies would clarify whether the association reflects a causal pathway or an unmeasured confounder.

Conclusion

This study adds to a body of evidence suggesting that long-term use of PDE5 inhibitors, and tadalafil in particular, may carry eye-related risks. It does not mandate abrupt changes in prescribing, but it does argue for precaution: baseline ophthalmic assessment, regular follow-up for patients on chronic therapy, and prompt evaluation of any new visual symptoms. Better data will refine guidance, but for now coordinated care offers a practical balance between symptom control and eye safety.