Corneal Astigmatism

• Faculty of Medicine, Assiut University — Asyut, Egypt

• Empire Eye & Laser Center — Bakersfield, California, United States
• Southern California Eye Physicians & Associates — Long Beach, California, United States
• Santa Monica Eye Medical Group — Santa Monica, California, United States
• Wolstan & Goldberg Eye Associates — Torrance, California, United States

• Alcon Investigator 8117 — Campsie, New South Wales, Australia
• Alcon Investigator 7678 — Sydney, New South Wales, Australia
• Alcon Investigator 7813 — Footscray, Victoria, Australia
• Alcon Investigator 8122 — Saint Albans, Victoria, Australia

• Centre hospitalier de l'Université de Montréal (CHUM) — Montreal, Quebec, Canada

Not specified

• Alcon Investigative Site — Chiyoda-Ku, Tokyo, Japan

• Department of Ophthalmology; Medical Faculty Carl Gustav Carus; Technical University Dresden — Dresden, Saxony, Germany

• Empire Eye and Laser Center, Inc. — Bakersfield, California, United States
• University of California — Los Angeles, California, United States
• Jones Eye Clinic — Sioux City, Iowa, United States
• Vance Thompson Vision, ND — West Fargo, North Dakota, United States

• Empire Eye & Laser Center — Bakersfield, California, United States
• Jones Eye Clinic — Sioux City, Iowa, United States
• Chesapeake Eye Care and Laser Center — Annapolis, Maryland, United States
• Eye Doctors of Washington — Chevy Chase, Maryland, United States

• Empire Eye & Laser Center — Bakersfield, California, United States
• Wolstan & Goldberg Eye Associates — Torrance, California, United States
• Katzen Eye Care & Laser Center — West Palm Beach, Florida, United States
• Jones Eye Clinic — Sioux City, Iowa, United States