Lead Sponsor: Jeremy Keenan, MD, MPH

Collaborators: National Eye Institute (NEI), University of Pennsylvania, University of California, Los Angeles, University of Miami, University of Iowa, Columbia University, Oregon Health and Science University, University of Pittsburgh, University of Florida, Johns Hopkins University, University of Illinois at Chicago, Aravind Eye Care System, Moorfields Eye Hospital NHS Foundation Trust, Federal University of São Paulo

Intervention / Treatment: DRUG: Topical corticosteroid, OTHER: Topical placebo, DRUG: Polyhexamethylene biguanide (PHMB)

Lead Sponsor: University of California, San Francisco

Intervention / Treatment: DRUG: Placebo, DRUG: Doxycycline 40 MG ( 20mg twice daily), DRUG: Doxycycline 200 MG ( 100 mg twice daily)

Lead Sponsor: Thomas M. Lietman

Collaborators: National Eye Institute (NEI), Stanford University, University of Miami, Aravind Eye Care System

Intervention / Treatment: OTHER: Topical Placebo, DRUG: Riboflavin Ophthalmic, DRUG: Moxifloxacin Ophthalmic, DRUG: Difluprednate Ophthalmic