PDE5 Inhibitor Use and Non-arteritic Anterior Ischemic Optic Neuropathy (NAION)

Prospective Case Crossover Study to Assess Whether PDE5 Inhibitor Exposure in Men Increases the Risk for the Development of Non-arteritic Anterior Ischemic Optic Neuropathy (NAION)

The primary objective of this study is to determine whether the use of PDE5 inhibitors (vardenafil, sildenafil, or tadalafil) increases the risk for the development of NAION.

Collected data will be compared to historic data of the same participant in case-crossover design.

Inclusion Criteria:

• NAION onset within 45 days before entry to the study
• NAION onset definable by the subject within a 2 calendar day window
• Men who have taken at least 1 dose of PDE5 inhibitor(s) at any time in the 1 year prior to enrollment in the study
• Age 40 years or older

Exclusion Criteria:

• History of multiple sclerosis or optic neuritis
• Evidence of temporal arteritis
• History of vasculitis or collagen vascular disease
• Previous history of NAION