Tests and diagnosisBy Mayo Clinic staff
Be prepared for an eye exam and a few tests to see how your tears are draining. Your doctor will also examine the inside of your nose to determine if any structural disorders of your nasal passages are causing an obstruction. If a blocked tear duct is suspected, other tests may be performed to find the location of the blockage in order to choose the best treatment.
Some of the tests used to diagnose a blocked tear duct include:
- Tear drainage test. Called a fluorescein (flooh-RES-een) dye disappearance test, this test measures how quickly your tears are draining. One drop of a special dye is placed in each eye. If there's still a significant amount of dye in your eye after five minutes of normal blinking, you may have a blocked tear duct.
- Irrigation and probing. Your doctor may flush a saline solution through your tear drainage system to check how it's draining, or use a slender instrument (probe) inserted through the tiny drainage holes at the corner of your lid (puncta) to check for blockages. During this probing, the puncta usually dilates and if the problem is simply a narrowed puncta, this procedure may resolve the problem.
- Eye imaging tests. Tests include dacryocystography (DAK-rye-oh-sis-tog-ruh-fee) or dacryoscintigraphy (DAK-rye-oh-sin-tig-ruh-fee). For these procedures, a contrast dye is passed from the puncta in the corner of your lid through your tear drainage system. Then, X-ray, computerized tomography (CT) or magnetic resonance imaging (MRI) images are taken to find the location and cause of the blockage.
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