The clinical evaluation of the lacrimal drainage system was originally outlined by Lester Jones. Evaluation was in the form of a dye disappearance test followed by a Jones I and Jones II test. By using this sequence (with modifications) as a guide, the physician can frequently streamline diagnostic testing.
The dye disappearance test (DDT) is useful for assessing the presence or absence of adequate lacrimal outflow, especially in unilateral cases. It is more heavily relied upon in children, in whom lacrimal irrigation is impossible without deep sedation. Using a drop of sterile 2% fluorescein solution or a moistened fluorescein strip, the examiner instills fluorescein into the conjunctival fornices of each eye and then observes the tear film, preferably with the cobalt blue filter of the slit lamp. Persistence of significant dye and, particularly, asymmetric clearance of the dye from the tear meniscus over a 5-minute period indicate an obstruction. Unilateral delayed dye disappearance is illustrated in Figure 13-6. If the DDT result is normal, severe lacrimal drainage dysfunction is highly unlikely. However, intermittent causes of tearing such as allergy, dacryolith, or intranasal obstruction cannot be ruled out.
, BersaniTA, FruehBR, MuschDC. Efficacy of the primary dye test.1989;96(4):481–483.
The Jones I and Jones II tests have historically been used in the evaluation of epiphora. Like the DDT, the Jones I test, or primary dye test, investigates lacrimal outflow under normal physiologic conditions. The examiner instills fluorescein into the conjunctival fornices and recovers it in the inferior nasal meatus by passing a cotton-tipped wire applicator into the region of the ostium of the NLD at 2 and 5 minutes. As this test occasionally yields abnormal results in normal patients, it is not uniformly performed.
The nonphysiologic Jones II test determines the presence or absence of fluorescein in the irrigating saline fluid retrieved from the nose. This test is performed as follows. The residual fluorescein is flushed from the conjunctival sac following an unsuccessful Jones I test. This is done so that the examiner can determine whether any reflux upon irrigation contains fluorescein. Irrigation of the lacrimal drainage system is performed with clear saline, which is retrieved from the inner aspect of the nose. Although some clinicians continue to use and rely on formal Jones testing, most have found retrieving the irrigating fluid from the nose to be technically difficult and have abandoned the test. Instead, they employ a simplified approach, using only the DDT and lacrimal irrigation.
Lacrimal drainage system irrigation is most frequently performed immediately after a DDT to determine the level of lacrimal drainage system occlusion (Fig 13-7). After instillation of topical anesthesia, the lower eyelid punctum is dilated, and any punctal stenosis noted. The irrigating cannula is placed in the canalicular system. To prevent canalicular kinking and difficulty in advancing the irrigating cannula, the clinician maintains lateral traction of the lower eyelid (see Fig 13-1). Canalicular stenosis or occlusion should be noted and confirmed by subsequent diagnostic probing. Once the irrigating cannula has been advanced into the horizontal canaliculus, clear saline is injected and the results noted. Careful observation and interpretation determine the area of obstruction without additional testing.
Difficulty advancing the irrigating cannula and an inability to irrigate fluid suggest total canalicular obstruction. If saline can be irrigated successfully but it refluxes through the upper canalicular system, and if no distension of the lacrimal sac is noted with palpation, complete blockage of the common canaliculus is suggested (Fig 13-8). Subsequent probing determines whether the common canalicular stenosis is total or whether it can be dilated. If mucoid material or fluorescein refluxes through the opposite punctum with palpable lacrimal sac distension, then the diagnosis is complete NLD obstruction. If saline irrigation is not associated with canalicular reflux or fluid passing down the NLD, then distension of the lacrimal sac with significant patient discomfort will occur. This result confirms a complete NLD obstruction with a functional valve of Rosenmüller preventing reflux through the canalicular system. A combination of saline reflux through the opposite canaliculus and saline irrigation through the NLD into the nose may indicate a partial NLD stenosis.
If saline irrigation passes freely into the nose with no reflux through the canalicular system, a patent nasolacrimal drainage system is present. However, it is important to note that even though this irrigation is successful under a nonphysiologic condition such as increased hydrostatic pressure on the irrigating saline, a functional obstruction may still be present. A dacryolith may also impair tear flow without blocking irrigation.
Diagnostic probing of the upper system (puncta, canaliculi, lacrimal sac) is useful in confirming the level of obstruction. In adults, this procedure can easily be performed with topical anesthesia. A small probe (00) should be used initially to detect any canalicular obstruction. If an obstruction is encountered, the probe is clamped at the punctum before withdrawal, thereby measuring the distance to the obstruction. A large probe may be useful to determine the extent of a partial obstruction, but the probe should not be forced through any area of resistance.
Diagnostic probing of the NLD has no place in adults because there are other means of diagnosing NLD obstruction. Also, probing in adults has limited therapeutic value, rarely producing lasting patency. In contrast, probing in infants is a useful and largely successful procedure. This reflects the differing pathophysiologies of congenital and acquired NLD obstruction, with the former often resulting from a thin membrane occluding the NLD and the latter from more extensive fibrosis of the duct itself.
Nasal endoscopy allows for direct visualization of the lacrimal passages. Diagnostic endoscopy takes only a few minutes to perform and is helpful in the evaluation of the nasal anatomy and in the identification of disease processes. Endoscopy can be performed prior to surgical correction of NLD obstruction, particularly if direct visualization is difficult.
Contrast dacryocystography and dacryoscintigraphy aid in the evaluation of the anatomy and function of the lacrimal drainage system. However, they are now used infrequently, primarily because alternate methods of evaluation are available such as simple irrigation and modern imaging techniques (CT and MRI). Contrast dacryocystography provides anatomical information with dye injection into the lacrimal system followed by computerized digital subtraction imaging. Dacryoscintigraphy provides physiological information using radionucleotide drops to follow tear flow using a scintigram.
Computed tomography and magnetic resonance imaging are useful after craniofacial injury, in congenital craniofacial deformities, or for suspected neoplasia. CT is superior in the evaluation of suspected bony abnormalities, such as fractures. It also allows assessment of the position of the cribriform plate, thereby helping to avoid injury at the time of surgery and subsequent cerebrospinal fluid leakage. MRI is superior in the evaluation of suspected soft-tissue disease, such as malignancy. Either CT or MRI may be helpful in evaluating concomitant sinus or nasal disease that may contribute to excess tearing.
, ChingAS, HoangTA, et al. Clinical and radiologic lacrimal testing in patients with epiphora.1997;104(11):1875–1881.