Tonography is used to determine

Tonography Tonography is a non-invasive technique for determining the facility of aqueous outflow (C-value). The C-value is expressed as aqueous outflow in microlitres per minute per millimetre of mercury. It is estimated by placing Schiotz tonometer on the eye for 4 minutes. For a graphic record the electronic Schiotz tonometer is used. C-value is calculated from special tonographic tables taking into consideration the initial IOP (P0) and the change in scale reading over the 4 minutes. Ref:- A K KHURANA; pg num:-481