Participants with non-ocular, medically significant co-morbid conditions that impair normal activities, require immunosuppression, or who have a condition with a prognosis that indicates a significant risk of disability or death if the condition were to continue or be exacerbated during the study period, or a medical condition that would likely have an impact on the participant's ability to comply with the visit schedule. Such conditions may include, for example, recent heart attack, significant COPD, brittle diabetes, kidney disease, severe emphysema, organ transplant (requiring corticosteroids or other immunosuppressive medications), hepatitis or other liver disease, or uncontrolled psychiatric illnesses.