Sandhu Sukhpal Singh, Chattopadhyay Sandip, Birch Michael Kevin, Ray-Chaudhuri Neeta
Department of Ophthalmology, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom.
J Glaucoma. 2005 Jun;14(3):215-8. doi: 10.1097/00061198-200506000-00009.
To investigate how quickly Goldmann applanation tonometers used in clinical practice develop calibration errors, and to determine the frequency of checks required to detect these errors.
Prospective check of the calibration error of all Haag-Streit Goldmann applanation tonometers in the department at month zero, month one, and month four. The tonometers were checked according to the Haag-Streit method using a standard calibration check weight bar by two independent observers. Calibration errors were classed as +/-0.5 to 2.5 mm Hg, +/-3 to 4 mm Hg, or >+/-4 mm Hg. Tonometers with a calibration error greater than +/-2.5 mm Hg were returned to the manufacturer for re-calibration.
At month zero 2 of 34 (5.9%), at month one 3 of 29 (10.3%), and at month four 0 of 33 (0.0%) tonometers fell within the manufacturer's recommended calibration range of +/-0.5 mm Hg. A total of 14 of 34 (41.2%) tonometers at month zero, 10 of 29 (34.5%) tonometers at month one, and 17 of 33 (51.5%) tonometers at month four were identified to have calibration errors greater than +/-2.5 mm Hg.
Goldmann applanation tonometers are not as accurate as the manufacturer's recommended calibration error tolerance of +/-0.5 mm Hg would suggest. Calibration error of less than +/-2.5 mm Hg is clinically acceptable. Calibration error checks should be carried out once monthly and tonometers with calibration error greater than +/-2.5 mm Hg returned to the manufacturer for re-calibration. Additional checks should be made if tonometers suffer specific damage. Ideally individual ophthalmologists should check calibration before each session.
研究临床实践中使用的戈德曼压平眼压计产生校准误差的速度，并确定检测这些误差所需的检查频率。
在第零个月、第一个月和第四个月对科室所有Haag-Streit戈德曼压平眼压计的校准误差进行前瞻性检查。由两名独立观察者根据Haag-Streit方法，使用标准校准检查配重杆对眼压计进行检查。校准误差分为±0.5至2.5毫米汞柱、±3至4毫米汞柱或>±4毫米汞柱。校准误差大于±2.5毫米汞柱的眼压计返回制造商进行重新校准。
在第零个月，34台眼压计中有2台（5.9%），在第一个月，29台中有3台（10.3%），在第四个月，33台中有0台（0.0%）落在制造商推荐的±0.5毫米汞柱校准范围内。在第零个月，34台眼压计中有14台（41.2%），在第一个月，29台中有10台（34.5%），在第四个月，33台中有17台（51.5%）被确定校准误差大于±2.5毫米汞柱。
戈德曼压平眼压计并不像制造商推荐的±0.5毫米汞柱校准误差容限所显示的那样准确。校准误差小于±2.5毫米汞柱在临床上是可以接受的。校准误差检查应每月进行一次，校准误差大于±2.5毫米汞柱的眼压计返回制造商进行重新校准。如果眼压计受到特定损坏，应进行额外检查。理想情况下，每位眼科医生在每次检查前都应检查校准情况。
