Penedones A, et al. - Via performing a literature search at MEDLINE, EMBASE, Toxline and VigiBase, researchers evaluated the risk of nonarteritic anterior ischaemic optic neuropathy correlated with phosphodiesterase type 5 inhibitors exposure. It included randomized controlled trials, observational studies, case reports and spontaneous reports describing nonarteritic anterior ischaemic optic neuropathy connected with phosphodiesterase type 5 inhibitors exposure. According to Centre for Reviews and Dissemination's guidance, the risk of bias was assessed. It identified four observational studies, 50 case reports and 608 spontaneous reports. According to this systematic review and meta-analysis, treatment with phosphodiesterase type 5 inhibitors was not linked to an increased risk of definitive nonarteritic anterior ischaemic optic neuropathy. In order to study such an association, further research is required, including possible confounding factors.