[1] Univ Ottawa, Inst Eye, Ottawa Hosp, Dept Ophthalmol, Ottawa, ON K1H 8L6, Canada
[2] Univ Thessaloniki, Glaucoma Unit, Dept Ophthalmol, AHEPA Hosp, Thessaloniki, Greece
[3] New York Eye & Ear Infirm, New York, NY 10003 USA
[4] New York Med Coll, Valhalla, NY 10595 USA