731
The former patient had complained once that his visual acuity had decreased after the termination of IFN therapy, and the latter patient complained twice during IFN therapy that his visual acuity had decreased.
 The former patient: Subject; visual acuity had decreased: Effect; IFN: Treatment; IFN: Treatment.Drug
Given event type and trigger, please tell me the arguments of all the listed option. Output format is "name1: role1; name2: role2". 
Event type: adverse event 
  Option: Treatment.Freq, Subject.Population, Combination.Drug, Subject.Gender, Treatment.Duration, Subject, Effect, Treatment, Treatment.Disorder, Subject.Disorder, Treatment.Route, Subject.Race, Treatment.Time_elapsed, Treatment.Dosage, Subject.Age, Treatment.Drug 
Text: {0} 
Answer:
 The former patient: Subject; visual acuity had decreased: Effect; IFN: Treatment; IFN: Treatment.Drug