RT Journal Article SR Electronic T1 Use of the Perkins hand-held applanation tonometer in retinal detachment surgery. JF British Journal of Ophthalmology JO Br J Ophthalmol FD BMJ Publishing Group Ltd. SP 644 OP 646 DO 10.1136/bjo.55.9.644 VO 55 IS 9 A1 Chignell, A H YR 1971 UL http://bjo.bmj.com/content/55/9/644.abstract AB