[Tonometry in change. From indentation and applanation to contour adaptation].
The dynamic contour tonometer (DCT) is the first and only noninvasive contact tonometer that is capable of measuring intraocular pressure (IOP) directly and continuously. The touch of the pressure-sensitive tonometer tip induces the cornea to gently assume a shape (contour) which it will naturally assume when pressure on both sides is equal. A force field establishes between tonometer tip and cornea, that corresponds exactly to IOP. A piezoresistive pressure sensor, integrated into the surface of the tonometer tip, precisely measures IOP continuously and therefore also records time-dependent modulations of IOP as "ocular pulse amplitude" (OPA). Dependence of the DCT on biomechanical properties of the cornea is substantially smaller than with traditional tonometers that applanate or indent the cornea.
Kanngiesser
H
H
SMT AG, Port, Schweiz. kanngiesser@smtag.ch
Kniestedt
C
C
D003315:Cornea / Q000503:physiopathology*; D005901:Glaucoma / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure; D009798:Ocular Hypertension / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology*; D017410:Practice Guidelines as Topic; D010818:Practice Patterns, Physicians'; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D012680:Sensitivity and Specificity; D014065:Tonometry, Ocular / Q000295:instrumentation / Q000379:methods*