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Assessment of lacrimal resistance in patients with patent lacrimal systems is important in determining whether dacryocystorhinostomy (DCR) surgery is appropriate. Current techniques, including lacrimal syringing and dacryoscintigraphy (DSG), can be unreliable. We compare the results of a manometric tear duct test (mTDT) irrigation technique with DSG in these patients. All symptomatic patients in a specialist lacrimal clinic had full work-up apart from syringing. Lacrimal resistance was assessed using mTDT which applies a fixed head of fluid pressure via a cannula sealed to punctum. Conventional syringing was also performed in cases with abnormal mTDT. Symptomatic patients with delayed tear clearance, no external cause for watering and patent lacrimal systems had DSG. MTDT and DSG results were compared, including in asymptomatic fellow eyes. 105 tear ducts were examined, 85 symptomatic. Symptomatic eyes had a significantly higher mean mTDT resistance (p =.0003) and more had abnormal mTDT (52%) compared to asymptomatic eyes (10%). Although mean tear duct resistance was higher in those with nasolacrimal duct stenosis (NLDS) than freely patent (FP) on syringing (8.5 vs 10.8 dpm), this was not significant (p =.6). High proportions of both FP and NLDS groups had no flow at all on mTDT (60% and 53%, respectively). DSG showed no significant difference in the symptomatic versus asymptomatic eyes (p =.36), nor between those with a normal or abnormal mTDT (p =.25), nor between FP and NLDS groups (p =.25). In contrast to DSG, the mTDT provides valuable, objective information on lacrimal resistance that can guide a decision to DCR surgery. [ABSTRACT FROM AUTHOR]

Lacrimal scintigraphy (LS) or dacryoscintigraphy can demonstrate abnormalities in 80%-95% of patients with symptoms of epiphora and a patent lacrimal system on syringing and up to 40% asymptomatic individuals. Precise localization of the site of delay may not always be possible due to lack of anatomic detail on LS. LS is considered useful in patients with epiphora with delayed tear clearance and patency to syringing and suspected to have either nasolacrimal duct (NLD) stenosis or lacrimal pump failure. It remains unclear, however, as to whether LS can reliably distinguish between the two. The literature reports considerable variation in the technique, normative data, analysis, and interpretation of LS. Qualitative or visual analysis is simpler to perform and to our knowledge used more frequently in comparison to quantitative analysis. There is little extra information to be gained from LS in cases with complete NLD obstruction or severe NLD stenosis on syringing. [ABSTRACT FROM AUTHOR]

Background: Dacryoscintigraphy is a noninvasive method frequently used for assessment of the lacrimal drainage system. Sometimes conflicting results with patients' complaints are obtained, which have no clear explanation. In our hypothesis, follow-up of patients evaluated with dacryoscintigraphy could be helpful in determining possible explanations for these conflicting results. Method: Thirty-eight consecutive patients (76 eyes) who had not previously undergone dacryocystorhinostomy or probing were entered in the study. Following instillation of 4 MBq 99mTc-pertechnetate, a routine procedure of dacryoscintigraphy was performed. After a mean follow-up time of 1.2 ± 0.3 years (range 0.9-1.6 years), all patients were reassessed clinically. Results: Using initial patients' symptoms as the gold standard, the sensitivity, specificity, NPV, and PPV of dacryoscintigraphy were calculated to be 82.1%, 75%, 60%, and 90.1%, respectively. The kappa value as a measure of agreement was 0.52. Considering the follow-up study as the gold standard, the sensitivity, specificity, NPV, and PPV were calculated as follows, respectively: 96.3%, 90.4%, 96.3%, and 90.4%. The kappa value was 0.86. There were three initially symptom-free eyes with obstructive pattern on the scans, which developed epiphora on the follow-up. In fact, these eyes were initially classified as false positive, but follow-up assessment showed that they were true-positive scans in a subclinical state. Conclusion: Despite certain drawbacks inherent to the technique, dacryoscintigraphy provides valuable independent information and allows more accurate management decisions. In some patients, data obtained from lacrimal scintigraphy could be predictive, and it makes possible determination of subclinical nasolacrimal duct obstructions. [ABSTRACT FROM AUTHOR]

Background: At the present time, only visual analysis is implemented on dacryoscintigraphic images and quantitative assessments are not routinely obtained. The authors have designed a novel, simple, quantitative method for the diagnosis of sac and post-sac obstructions based on the dacryoscintigraphic images. Method: Fifty-nine patients with severe unilateral epiphora were included and the contralateral asymptomatic eyes were used as controls. After ocular instillation of 0.1 cc isotonic saline containing 4 MBq 99mTcO4, dynamic images were obtained for 20 minutes. Visual interpretation was done by two blinded specialists in nuclear medicine. A Time-Activity Curve (TAC) was generated for each eye and its pattern was divided to plateau type, shallow-down sloping and deep-down sloping. The excretion ratio (expressed as the percentage of drained activity) in the 2nd, 3rd, 5th, 7th, 10th, 15th and 20th minute of the study was calculated based on the following formula: (the total count in the region of interest (ROI) in the 1st minute - the total ROI count in the 2nd, 3rd, 5th, 7th, 10th, 15th or 20th minute/the total ROI count in the 1st minute) × 100. The results of the quantitative analysis were compared with the clinical symptoms, visual analysis and TAC pattern. Results: At the optimal cut-off points for the 2nd, 3rd, 5th and 7th minute, the sensitivity of the prediction of obstruction was 76%, 72%, 71% and 69%, respectively. The correlation between visual interpretation and the TAC pattern was statistically significant. Conclusion: The quantitative evaluation of dacryoscintigraphic images would contribute greatly to achieving an easier and more objective interpretation of the scintigraphic results and also provides a reliable tool for inter-individual comparison and the follow-up of patients. As it is the first time that this innovative method has been examined clinically, it will be necessary to investigate its clinical utility in a larger series of patients. [ABSTRACT FROM AUTHOR]

Radionuclide dacryocystography (RNDCG) is a safe, physiologic method of evaluating lacrimal drainage. The technique is performed by placing a radioactive ``tear'' in the eye(s) and following the passage of radioactivity through the lacrimal drainage apparatus with a scintillation (gamma) camera. RNDCG is indicated in any patient with tearing who has a lacrimal drainage system which is open to irrigation. It is also useful in children, when clinical signs are equivocal. Interpretation is made by comparing a patient's scan to ``normal'' scans, or in unilateral cases, by comparing the symptomatic side to the asymptomatic side. Many causes of functional or partial lacrimal drainage obstruction can be detected and differentiated from various tear hypersecretion abnormalities. RNDCG also has many research applications. [ABSTRACT FROM AUTHOR]

We report a 37-year-old patient with the history of bilateral epiphora, who was referred to our department for dacryoscintigraphy imaging. The patient had bilateral obstruction of the lacrimal apparatus at the sac-duct level on the scintigraphy images. Delayed imaging showed Tc-99m pertechnetate uptake in the thyroid due to systemic absorption of the tracer from the conjunctiva. We recommend using tracers with large particle size and lower possibility of mucosal absorption for dacryoscintigraphy in order to decrease unnecessary thyroid radiation. [ABSTRACT FROM AUTHOR]