Perkins hand-held applanation tonometer. A clinical evaluation.

MANY ophthalmologists measure intra-ocular pressure with the Goldmann tonometer. It is neither portable nor capable of being used with the patient supine, which is disadvantageous in glaucoma screening programmes when it is often necessary to examine sick patients in their homes. An applanation tonometer, which is portable and can be used with the patient supine, sitting, or even standing, has been described by Perkins (1965). This paper reports the results of two field trials in which a prototype of the Perkins hand-held applanation tonometer was used. Measurements obtained with it are compared with measurements made on the same eyes using a Goldmann tonometer.