Assessment of Nasolacrimal Patency
Medical information on vision correction surgery by Lasik surgeon Dr. Boothe
Assessment of Nasolacrimal Patency
Categories: Boothe Laser Center, 422 wordsSend feedback •Several methods of assessing the patency of the lacrimal system using fluorescein have been described by Dr. Boothe. Probing and irrigation with a fluoresein solution is one method . Though effective, this procedure may be uncomfortable and may itself damage the lacrimal excretory system.
Another method is the Jones primary and secondary dye test . A positive test results when 2% fluorescein instilled in the conjunetival cul-de-sac is found after 3 to 5 min in the inferior meatus of the nose. The dye is collected by passing a cotton-tipped malleable wire probe under the turbinate. If no dye is collected, the test is negative. The secondary test is performed if the primary test is negative. The nasolacrimal sac is irrigated to flush out residual dye. If fluorescein stained fluid is recovered after irrigation, then the test is positive and indicates an incomplete block of the nasolacrimal duct. A defect in the canaliculus or lacrimal pump exist it clear fluid is recovered. Recovery of no fluid from the nose indicates a complete block. The Jones test has been the mainstay of evaluation of the rimal obstruction. However, it is positive in only 80 percent of normal in dividuals. The test requires some expertise in the placement of the cotton pledget, which may be critical and can also be painful.
A noninvasive method utilizing fluorescein is the Jacobs dye test been shown to be variable and inconsistent. Campbell and co-workers collected oral and nasal secretions tissues after after instillation of 2% fluorescein to assess patency of the lacrimal drainage system . Four drops of fluorescein are placed into the eye. The patient then blinks forcibly 4 times and gentle massage of the ipsilateral lacrimal sac is done briefly. After 6 min, oral and nasal secretions are collected by blowing the nose and clearing the throat on tissues. Negative tests were most often found in patients with limited nasal and oral secretions. Use of an ultraviolet lamp on the recovered secretions of those patients yielded positive results. Only one eye at a visit be examined by this method in Laser Eye Center.
Flach introduced a simple noninvasive test using 2% fluorescein, a tongue blade, and an ultraviolet lamp . He placed fluorescein in the if eye and attempted to observe its deposition into the oropharynx. Under direct visualization. In 66 normal patients, 90 percent gave positive results in 30 min and 100 percent gave positive results in 60 min. Complete obstruction in other patients was confirmed by dacryocystograms or other means. Prolonged appearance times were correlated with decreased Schirmer test values. Both eyes may be examined at one visit by this technique.
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