2007 ICD-9-CM Procedure 89.11 Tonometry Measurement of the pressure or tension of liquids or gases with a tonometer. It has been developed to measure pressure in the EYE; the BLOOD VESSELS; and the STOMACH. 89.11 is a specific code that can be used to specify a procedure 89.11 contains 3 index entries View the full Volume 3 89.* hierarchy Index entries containing 89.11: Measurement intraocular tension or pressure 89.11 as part of extended ophthalmologic work-up 95.03 Perilimbal suction 89.11 Tonometry 89.11