The risk of developing one of three serious eye conditions increases by 85% for regular users of common erectile dysfunction (ED) medications such as Viagra, Cialis, Levitra and Stendra, according to new research by the University of Columbia (UBC).

Serous retinal detachment (SRD) and retinal vascular occlusion (RVO) had previously only been anecdotally linked to ED medications, but their association, together with ischaemic optic neuropathy (ION), has now been confirmed by a large, epidemiological study published in JAMA Ophthalmology. “These conditions are rare and the risk of developing one remains very low for any individual user,” said study lead Associate Professor Mahyar Etminan, UBC Faculty of Medicine. “However, the sheer number of prescriptions dispensed each month in the US – about 20 million – means that a significant number of people could be impacted.”

While the study showed only a statistical association between eye conditions and ED medications use, the drugs’ mechanisms suggest some possible explanations, said A/Prof Etminan. “These medications address erectile dysfunction by improving blood flow, but we know that they can also hinder blood flow in other parts of the body. So, although our study doesn’t prove cause and effect, the totality of the evidence points towards a strong link.”

Though they receive information about ION risk, ED medication patients are not warned about the risks of SRD or RVO, said A/Prof Etminan. “Patients who are unaware of all potential side effects might not seek help in time to avoid serious visual consequences.”