A Study to Assess Whether PDE5 Inhibitors Increase the Chance of Triggering the Onset of Acute NAION

Number of Days Exposed to PDE5i During 1-Day Case Window and 29 1-Day Control Windows Among Participants Adjudicated as Definite NAION Cases

Adjudication committee classified participants as Definite, Possible, or Non-NAION cases, or insufficient information available or unable to adjudicate. Case window: 1 day preceding symptom onset day; 29 control windows: 29 days preceding case window. A case or control window was considered exposed if: sildenafil/vardenafil was used on that day and/or previous day; tadalafil was used on that day and/or any of previous 4 days. In this analysis, each participant contributed exposure information for 1 case window and 29 control windows.

Time frame: 30-day period prior to onset of NAION symptoms