A case from Tehran Medical University describes a 32 year old man who experienced sudden, unilateral blindness following the ingestion of sildenafil. The incident was documented in the Journal of Medical Case Reports.
The patient took 100 mg of sildenafil, which is the primary active ingredient used to treat erectile dysfunction. This dose stands at the upper limit of the commonly recommended range and is twice the standard advised amount. About three hours after taking the medication, the man abruptly lost vision in one eye.
Medical imaging revealed clots forming in both the arterial and venous systems supplying blood to the affected eye. This vascular event led to swelling of the retina. Despite prompt efforts by clinicians to restore blood flow and preserve vision, the extent of retinal damage proved too severe to recover. The case notes that persistent intraocular pressure from fluid accumulation contributed to the retina eventually detaching from the surrounding eye tissue.
Review of the patient’s history showed no family predisposition to clotting disorders that could account for such an event. The authors acknowledge that the exact mechanism by which sildenafil could harm ocular blood vessels remains unclear. These observations underscore the need for caution and further research.
One explanation proposed in the report is that while sildenafil aims to enhance blood flow to the penis, a similar vasodilatory action might unintentionally affect delicate vessels in the eye. The authors stress that additional studies are necessary to determine whether there is a causal link and to understand the underlying biology.
In the broader medical literature, this case adds to a body of reports on rare ocular complications associated with phosphodiesterase type 5 inhibitors. Clinicians are advised to consider visual symptoms as a potential adverse event in patients who recently used these medications, especially at higher doses. The report points to the importance of patient education and the need for careful dosing discussions with healthcare providers. Further epidemiological work is needed to quantify risk and identify any patient groups who might be more susceptible.
Historically, reports of unusual visual changes linked to sildenafil use have prompted calls for vigilance and pharmacovigilance. While this single case cannot establish causation, it highlights a potential hazard that merits attention in medical practice and patient counseling. The authors encourage physicians to monitor for signs of retinal or vascular complications and to document any similar occurrences to support a clearer understanding of risk factors and mechanisms.
In summary, the Tehran case illustrates a rare but serious outcome following a high dose of sildenafil. The rapid onset of vision loss, venous and arterial clots in the eye, and subsequent retinal detachment occurred despite no family history of clotting disorders. The precise biological pathway remains uncertain, and additional research is essential to determine whether a dose related effect exists and to identify susceptible populations. The report serves as a reminder that even widely prescribed medications can have unexpected ocular effects, reinforcing the need for informed use and ongoing scientific inquiry.