In obstructive disorders or stenosis of the lacrimal drainage system (inflammatory or traumatic), lacrimal scan helps diagnosis of tear flow disturbances and follow-up for the detection of therapy response: Detection of subclinical lacrimal duct obstruction. Differentiation between partial and complete blockage of the lacrimal drainage system.Accurate localization of the sites of lacrimal drainage obstruction, either at the canthus, or at the proximal, mid or distal parts of naso-lacrimal duct.Helping appropriate patient selection for surgery.Evaluating the success of dacryocystorhinostomy.

Patients with history of: Epiphora. Dacryocystitis.

Pregnancy. Lactation (stopped for 24 hours).

No specific preparations needed.

On arrival, the patient’s medical history is taken. After lying in front of the gamma camera, the patient’s head is held firmly with the use of a head-holder. The drop of radiopharmaceutical “99mTc-pertechnetate in physiologic saline solution (2–4 MBq in about 10 μl volume)” is applied to the conjunctiva on both sides. The overflowing tracer is wiped away. a series of dynamic images are taken at regular intervals for 20 minutes, after which the patient is asked to stay in the waiting room for about 30 minutes and is instructed to digitally massage over the nasolacrimal sac and duct then return for a further 2 minutes of imaging.

The examination is done by a state of the art Gamma Camera machines (produced by Philips and GE) at Mohandeseen, Heliopolis and New Cairo branches.
Patients should stay away from children (less than 12 years of age) and pregnant ladies, for at least 24 hours starting after administration of the radiotracer.