0071643192.pdf

IOP Measurement

INDICATIONS

■ To confirm the diagnosis of acute angle-closure glaucoma

■ To determine the ocular pressure after blunt ocular injury, or in patients

with iritis

CONTRAINDICATIONS

■ Relative:

■ Examination of infected eyes unless a sterilized cover can be used

■ The presence of corneal defects that may be further injured with

tonometry.

■ Absolute:

■ Suspected penetrating ocular injury

TECHNIQUE

■ Topical ocular anesthesia (proparacaine) must be instilled prior to procedure.

■ Several methods of measuring intraocular pressure:

■ Applanation tonometry: Measures the pressure required to create a flat

surface on the globe as determined by visual inspection of globe;

method used by the Goldmann tonometer

■ Electronic indentation tonometry: Used by the Tono-Pen

■ Impression tonometry: Measures depth of deflection of cornea created

by a known weight; used by the Schiotz tonometer

■ Pneumotonometry (air puff tonometry): Measures deflection of the

cornea in response to a puff of air

COMPLICATIONS

■ Corneal abrasions

■ Transmission of infection

■ Extrusion of ocular contents with penetrating injuries

INTERPRETATION OFRESULTS

■ Normal IOP is 10–20 mm Hg

■ A reading of >20% reliability using the Tono-Pen reflects an unreliable

measurement, which should be repeated.

You are performing a FAST exam on a patient in a car accident with abdomi-

nal pain but the image appears white. What do you do?

Decrease the gain. Consider also the possibility of subcutaneous air

from a pneumothorax.

ULTRASOUND

INDICATIONS

■ Ultrasound is useful in the evaluation of

■ Cholecystitis

■ Abdominal aortic aneurysm

■ Ectopic pregnancy

■ Pericardial tamponade

■ Hemoperitoneum

PROCEDURES AND SKILLS