RT Journal Article SR Electronic T1 FRIEDRICH P. FISCHER JF British Journal of Ophthalmology JO Br J Ophthalmol FD BMJ Publishing Group Ltd. SP 591 OP 592 DO 10.1136/bjo.33.9.591-a VO 33 IS 9 A1 A. S. YR 1949 UL http://bjo.bmj.com/content/33/9/591.2.abstract AB