This model of the Goldmann applanation tonometer is designed for the Haag-Streit BP 900, BQ 900 and BP 900 slit lamps. It mounts onto the microscope and can be swiveled into position when required.
The Applanation Tonometer AT 900 BQ is especially made to fit the BQ stereo-microscope. Apart from the working position, there are also two resting positions.
For perfect tonometric examination the tonometer is swung in front of the microscope and the illumination unit moved from the left to touch the bracket of the tonometer. In this position, the left and right eye of the patient can be examined without difficulties (no 60° position).
The measurement of the ocular pressure is carried out on the patient sitting at the slit lamp in conjunction with other routine microscopic examinations.
High accuracy of the measurement - the average deviation in any one single examination does not exceed ± 0.5 mm Hg.
The intraocular pressure in mm Hg is found by multiplying the drum reading by ten.
Scleral-rigidity is not to be taken into account as the small volumetric displacement of 0.56 mm3 increases the intraocular tension by about 2.5 % only.
Repeated measuring procedures do not reduce the ocular pressure, as no massaging effect occurs.
The instrument stays permanently mounted to the slit lamp and is swung into place when IOP readings are required.