A tonometer, which involves no mechanical contact with the eye, has been designed and Is being tested. An air pulse generated from the ambient atmosphere with a reliable positive linear force‐time ramp impinges upon the cornea. The pulse causes a gradual curvature reduction, applanation, and finally a slight concavity before the decaying force‐time ramp permits restoration. Telecentric optical‐electronic monitoring of the corneal vertex specular reflection unlqueiy identifies, In time, the applanation event. Both human and animal testing have demonstrated a direct linear relationship between intra‐ocular pressure and the time interval to applanation. This permits Instantaneous digital readout in mm Hg. An optical‐spherometer type system is utilized to effect alignment of the pneumatic and monitoring systems with the cornea In the three dimensions. Following alignment and triggering, measurement in the normal range takes approximately 3 milliseconds, does not require lid retraction, and induces only a blink reflex with no discomfort.

No abstract

A tonometer, which involves no mechanical contact with the eye, has been designed and Is being tested. An air pulse generated from the ambient atmosphere with a reliable positive linear force‐time ramp impinges upon the cornea. The pulse causes a gradual curvature reduction, applanation, and finally a slight concavity before the decaying force‐time ramp permits restoration. Telecentric optical‐electronic monitoring of the corneal vertex specular reflection unlqueiy identifies, In time, the applanation event. Both human and animal testing have demonstrated a direct linear relationship between intra‐ocular pressure and the time interval to applanation. This permits Instantaneous digital readout in mm Hg. An optical‐spherometer type system is utilized to effect alignment of the pneumatic and monitoring systems with the cornea In the three dimensions. Following alignment and triggering, measurement in the normal range takes approximately 3 milliseconds, does not require lid retraction, and induces only a blink reflex with no discomfort.

No abstract

The NON-CONTACTTM Tonometer is an applanation tonometer which, unlike all other tonometers, in measuring intraocular pressure makes no mechanical contact with the eye. Applanation -the flattening of an area of the eye -is achieved by a pulse of air whose force increases linearly with time. Applanation is detected opto-electronically and the interval of time required to produce applanation is utilized as the correlate of intra-ocular pressure. Measurement is accomplished in milliseconds without the use of topical anesthesia.