[1] Johns Hopkins Univ, Wilmer Eye Inst, Retina Div, Baltimore, MD 21218 USA
[2] Johns Hopkins Bayview Med Ctr, Ophthalmol, Baltimore, MD USA
[3] Clin Ojos Maracaibo, Maracaibo, Venezuela
[4] Clin Oftalmol Penaranda, Cucuta, Colombia
[5] Univ Texas Rio Grande Valley Sch Med, Biomed Sci, Brownsville, TX USA