Please assess the completion status of the following clinical trial:

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

Study Design Characteristics:
- Allocation: None
- Intervention Model: None
- Observational Model: CASE_CROSSOVER
- Primary Purpose: None
- Time Perspective: RETROSPECTIVE
- Masking: None
- Phase: None
- Number of Arms: None

Eligibility Criteria:
Inclusion Criteria:~* Male aged ≥45 years;~* Experienced abrupt visual change in only 1 eye~Exclusion Criteria:~* Pain determined by an ophthalmologist to be consistent with an inflammatory/arteritic process or optic neuritis;~* History of NAION or optic neuritis.~* Participation in other studies within 60 days prior to entry in the study.

- Gender: MALE
- Minimum Age: 45 Years
- Maximum Age: None
- Healthy Volunteers: f

Study Arms:
- Case Group (Type: None): None

Based on this trial design, predict the completion outcome and termination type (if applicable).