[1] Stanford Univ, Med Ctr, Sch Med, Dept Ophthalmol, Stanford, CA 94305 USA
[2] Columbia Univ, Dept Psychol, New York, NY 10027 USA
[3] Gartnavel Royal Hosp, Dept Ophthalmol, Glasgow, Lanark, Scotland
[4] Nagoya Univ, Sch Med, Dept Ophthalmol, Nagoya, Aichi 466, Japan
[5] Univ Eye Hosp, Dept 2, Tubingen, Germany