The little blue pill is touted as a life-saver and life-giver, but did you know that it can be a vision-killer as well?
A recent study published in JAMA Ophthalmology cautioned that regular use of phosphodiesterase type 5 inhibitors (PDE5Is) might lead to an increased risk for serous retinal detachment (SRD), retinal vascular occlusion (RVO) and ischemic optic neuropathy (ION).1
According to data from the Massachusetts Male Aging Study, up to 52% of men between the ages of 40 and 70 are affected by erectile dysfunction (ED).2 Meanwhile, the worldwide prevalence of ED is expected to increase to 322 million men by 2025.3 This means that the use of PDE5Is is going to increase down the road. In fact, Pfizer’s famous ED product Viagra generated around USD$500 million in revenue in 2019, and about USD$2 billion in revenue at its peak in 2012 (the year its patent protection expired outside the U.S.).4
Authors of the study examined 213,000 men in the U.S. who took erectile dysfunction (ED) medication, including sildenafil, tadalafil, vardenafil and avanafil, and found that there were 278 cases of SRD, 628 cases of RVO, and 240 cases of ION during the study period. Those who had SRD, RVO or ION were more likely to have had chronic medical conditions such as hypertension, diabetes, coronary artery disease and sleep apnea as well.
The adjusted incidence rate ratio (IRR) for the composite endpoints of any of the three outcomes (SRD, RVO and ION) was 1.85 (95% CI, 1.41-2.42; incidence, 15.5 cases per 10,000 person-years). The adjusted IRR for SRD, RVO, and ION as individual outcomes was 2.58 (95% CI, 1.55-4.30; incidence, 3.8 cases per 10,000 person-years); 1.44 (95% CI, 0.98-2.12; incidence, 8.5 cases per 10,000 person-years); and 2.02 (95% CI, 1.14-3.58; incidence, 3.2 cases per 10,000 person-years), respectively.
According to the authors, studies have found that PDE5Is may be associated with compromised perfusion of the optic nerve. Moreover, it is suggested that the choroid blood vessels can undergo smooth muscle relaxation through a cyclic guanosine monophosphate pathway that can lead to choroidal congestion.
“Findings of this cohort study suggest that regular users of PDE5Is might have an increased risk for SRD, RVO, and ION. Regular users of PDE5Is need to be cognizant of ocular adverse events associated with these drugs and alert their physicians if they experience any visual deficits,” the authors concluded.
So, do we treat erectile dysfunction and accept the risk to vision? Do men really need to choose one over the other? Matters like these are best placed in the hands of the experts, who can possibly find the point of balance that allows men to enjoy the best of both worlds.
References
- Etminan M, Sodhi M, Mikelberg FS, Maberley D. Risk of Ocular Adverse Events Associated With Use of Phosphodiesterase 5 Inhibitors in Men in the US. JAMA Ophthalmol. 2022 Apr 7 [Online ahead of print]
- Feldman HA, Goldstein I, Hatzichristou DG, et al. Impotence and its medical and psychosocial correlates: Results of the Massachusetts Male Aging Study. J Urol. 1994;151:54–61.
- Ayta IA, McKinlay JB, Krane RJ. The likely worldwide increase in erectile dysfunction between 1995 and 2025 and some possible policy consequences. BJU Int. 1999;84(1):50-6.
- Mikulic M. Pfizer: Viagra revenue 2003-2019. Statista. [Internet] Published on Mar 1, 2021. [cited Apr 12, 2022]. Available from: https://www.statista.com/statistics/264827/pfizers-worldwide-viagra-revenue-since-2003/
