Participating principal investigators and centers of the MacTel Study Group: Jose-Alain Sahel, MD, PhD, Centre Hopitalier National D'Optalmologie des Quinze-Vingts, Paris, France; Robyn Guymer, MD, Centre for Eye Research, East Melbourne, Australia; Gisele Soubrane, MD, PhD, FEBO, Clinique Ophtalmolgie de Creteil, Creteil, France; Alain Gaudric, MD, Hopital Lariboisiere, Paris, France; Steven Schwartz, MD, Jules Stein Eye Institute, UCLA, Los Angeles, CA, USA; Ian Constable, MD, Lions Eye Institute, Nedlands, Australia; Michael Cooney, MD, MBA, Manhattan Eye, Ear, and Throat Hospital, New York, NY, USA; Catherine Egan, MD, Moorfields Eye Hospital, London, UK; Lawrence Singerman, MD, Retina Associates of Cleveland, Cleveland, OH, USA; Mark C. Gillies, MD, PhD, Save Sight Institute, Sydney, Australia; Martin Friedlander, MD, PhD, Scripps Research Institute, La Jolla, CA, USA; Daniel Pauleikhoff, Prof. Dr, St. Franziskus Hospital, Muenster, Germany; Joseph Moisseiev, MD, The Goldschleger Eye Institute, Tel Hashomer, Israel; Richard Rosen, MD, The New York Eye and Ear Infirmary, New York, NY, USA; Robert Murphy, MD, The Retina Group of Washington, Fairfax, VA, USA; Frank Holz, MD, University of Bonn, Bonn, Germany; Grant Comer, MD, University of Michigan, Kellogg Eye Center, Ann Arbor, MI, USA; Barbara Blodi, MD, University of Wisconsin, Madison, WI, USA; Diana Do, MD, The Wilmer Eye Institute, Baltimore, MD, USA; Alexander Brucker, MD, Scheie Eye Institute, Philadelphia, PA, USA; Raja Narayanan, MD, LV Prasad Eye Institute, Hyderabad, India; Sebastian Wolf, MD, PhD, University of Bern, Bern, Switzerland; Philip Rosenfeld, MD, PhD, Bascom Palmer, Miami, FL, USA. Paul S. Bernstein, MD, PhD, Moran Eye Center, University of Utah, UT, USA. Joan W. Miller, MD, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA.