Dacryoscintigraphy Research Articles

Incompatibility of Lacrimal Syringing Test with Dacryoscintigraphy in Patients Undergoing Successful Dacryocystorhinostomy Surgery

Abstract Purpose The aim of our study was to evaluate the compatibility of lacrimal syringe test with dacryoscintigraphy (DSG) in the postoperative evaluation of external dacryocystorhinostomy (Ext-DCR) surgery. Material and Methods Thirty eyes of 30 patients suffering from unilateral epiphora with discharge and showing complete obstruction on lacrimal irrigation test were included in the study. Patients with dysfunctional lacrimal pump function, revision surgery, partial obstruction, and ocular surface diseases were not included in the study.Verification of the nasolacrimal duct obstruction (NLDO) was achieved with dye disappearance test, Jones test 1 (JT 1), and JT 2. According to the type of obstruction seen on DSG, patients were classified into two groups: presac and postsac obstruction. Patients with complete obstruction detected in the lacrimal syringing and dynamic scintigraphy underwent Ext-DCR, and the results were evaluated. Results Thirty patients, mean age 58.93 ± 12.11 years, all with unilateral NLDO were included in the study. All had grade 5 Munk score epiphora and discharge. The mean duration of obstruction was 24.57 ± 10.65 months. In the lacrimal irrigation test, all patients had complete obstruction in one eye, while the other eye was normal. According to preoperative DSG results, there were 20 (66.7%) patients with presac delay and 10 (33.3%) patients with postsac delay. All patients underwent Ext-DCR with silicone tube intubation and were followed for 1 year. Although there was symptomatic improvement in all patients and the lacrimal syringing test was patent, no change was seen in scintigraphy. Conclusion Although DSG is a sensitive nuclear medicine method, it is not useful for predicting the functional success of the Ext-DSR.

Comparing the diagnostic accuracy of MR dacryocystography (MRD) and dacryoscintigraphy (DSG) in NLDO-related acquired epiphora.

This study aimed to compare the diagnostic accuracy of MR dacryocystography (MRD) and dacryoscintigraphy (DSG) in the diagnosis of acquired epiphora related to NLDO. A total of 15 patients with acquired epiphora and suspected NLDO were included in this study. All patients underwent MRD and DSG examinations. MRD was performed using a 3-Tesla magnetic resonance imaging (MRI) scanner, while DSG involved injection of a radiotracer into the lacrimal drainage system followed by DSG. The results of both imaging methods were compared with the reference standard that was a combination of clinical examination findings and surgical exploration. The results of this study showed that no abnormal findings were observed in MR-DCG in patients before the Valsalva maneuver. However, after the Valsalva maneuver, stenosis/obstruction at the canal surface was observed in all 15 patients diagnosed by DSG, giving a sensitivity of 100% for canal stenosis. Moreover, the results revealed that among these 15 patients, 9 showed stenosis or simultaneous obstruction at the level of the canal and lacrimal sac, but MR-DCG showed these lesions in only 9 patients, giving a sensitivity of 60%. The specificity of MRD and DSG were 85% and 76.7%, respectively. There was a statistically significant difference in the sensitivity of MRD and DSG (p < 0.05). This study demonstrated that MRD has a higher diagnostic accuracy in the diagnosis of acquired epiphora associated with NLDO compared to DSG. MRD showed significantly higher sensitivity and specificity than DSG. Therefore, MRD can be considered as the preferred imaging modality in the diagnosis of acquired epiphora due to NLDO. By accurately identifying the underlying cause of NLDO, MRD can help determine the most appropriate treatment approach for patients and lead to better outcomes.

Outcomes of Endonasal Dacryocystorhinostomy Performed for Functional Nasolacrimal Obstruction With Delay on Dacryoscintigraphy.

To report the demographics and outcomes of endonasal dacryocystorhinostomy (DCR) following dacryoscintigraphy (DSG) performed for a series of patients with functional epiphora. Case series of endonasal DCR outcomes in patients with symptomatic epiphora with no evidence of lacrimal hypersecretion or lacrimal pump failure, minimal regurgitation noted on syringing, and DSG-confirmed delayed drainage. A successful outcome was defined as 80% subjective improvement or resolution of tearing on the operated side. Patient charts, DSG results, and operative records were examined, and data were collected. Relevant literature was reviewed and discussed. The case series included 15 eyes of 10 patients. The mean age was 61.7 years at the time of surgery. Most cases (n=13) had post-sac obstruction, retention, or delay. One patient had pre and post-sac retention. A total of 12 cases had success after endonasal DCR, and 3 cases had failure. Follow-up for all operated patients was over 6 months. There were no reported complications by the surgeon or patients. Patients with functional epiphora confirmed by DSG seem to have a high success rate after endonasal DCR. In patients with symptomatic epiphora with subjective patency on syringing, the use of DSG in decision-making and outcome prediction may be supported. Further studies, including clinic-based tests, to demonstrate functional obstruction are warranted.

Diagnostic accuracy of fluorescein dye disappearance test in comparison with lacrimal syringing in evaluation of epiphora

Epiphora is the overflow of tear in the lid margin. It can be due to hyper secretion or inadequate tear drainage. Inadequate drainage of tears may be due to mechanical or physiological causes. Physiological cause is due to lacrimal pump failure or weakness of orbicularis muscle. Mechanical causes are due to obstruction in the lacrimal passages. Evaluation of epiphora can be done by lacrimal syringing, fluoresceine dye disappearance test, Jones dye test, contrast dacryocystography, nuclear lacrimal scintigraphy, CT, MRI etc. Fluoresceine dye test is a non invasive method to study tear flow drainage system. Our study evaluate the effectiveness of dye disappearance test to lacrimal syringing which is a invasive test. Aim of this study was to evaluate the accuracy of fluorescein dye disappearance test [FDDT] in evaluating epiphora in comparison to lacrimal syringing.: A prospective observational study was conducted in 90 consecutive patients of age group of 40 to 70 years who presented with epiphora in Department of ophthalmology at tertiary care centre. Any cause like foreign body, trauma, blepharitis, lid disorders like ectropion, entropion, history of lacrimal sac surgeries in the recent past, and allergy to sodium fluorescein excluded from the study.A thorough medical history and comprehensive ophthalmological examination done in all patients. Epiphora evaluated with regurgitation over pressure on the lacrimal sac area, lacrimal syringing, and fluorseceine dye disappearance test.FDDT resulte were graded as grade 1 to 4 according to the quantity of flouorseceine stain in the conjunctival sac, Grade 1 and 2 considered as normal and grade 3 and 4 considered as abnormal.Results of FDDT, syringing, ROPLAS compared in the patients with epiphora.: In the study group, the 90 samples were analysed. The sample population were 62% males and 38% females. There were co-morbidities like diabetes mellitus and cataract noticed in the population. When we examined the diabetes mellitus patients presented with epiphora, showed lacrimal passage obstruction is more common in diabetes patients [67% patients among diabetes patients have FDDT of grade 2-3]. Regurgitation on pressure over lacrimal sac] test were done in all patients presented with epiphora, and the test was positive in 21 patients. FDDT were done in these patients and the results showed only 14 patients were Grade 2-3 [67%]. We compared the FDDT and lacrimal syringing tests in epiphora patients. Among the 90 patients we found that 60 individuals had patent nasolacrimal passages, verified by free flow in Lacrimal syringing test. FDDT showed majority of the patients were under grade 0-1 [patent nasolacrimal passages]. The patients with blocked nasolacrimal passages verified by lacrimal syringing were found grade 2-3 in FDDT [Blocked nasolacrimal passages]. Sensitivity, specificity, and positive and negative predictive value of FDDT were calculated.: FDDT is a safe and effective test for the evaluation of epiphora. It can be done as a screening test in pre operative evaluation of cataract surgery.

Dacryoscintigraphy as a guide for surgery in patients with functional epiphora

ObjectifDéterminer les éventuels bienfaits de la dacryoscintigraphie (DSG) dans la planification du traitement chirurgical de l’épiphora fonctionnel. MéthodesIl s'agit d'une étude multicentrique rétrospective portant sur une série de patients qui présentaient un larmoiement symptomatique en l'absence de cause externe nette et chez lesquels l'irrigation lacrymale et le sondage du canal lacrymal étaient normaux (en d'autres termes, un épiphora fonctionnel). Tous les patients ont subi une DSG avant l'intervention. Les patients ont été exclus si la DSG n’était pas en mesure de mettre au jour une obstruction de l’écoulement lacrymal. Les patients qui présentaient un retard de l’écoulement lacrymal avant son entrée dans le sac lacrymal (« pré-sac ») pendant la DSG ont subi une chirurgie visant à améliorer l’écoulement dans le sac lacrymal. Les patients qui présentaient un retard de l’écoulement lacrymal après le sac lacrymal (« post-sac ») pendant la DSG ont subi une dacryocystorhinostomie. La réussite chirurgicale reposait sur l'un des 3 critères suivants : disparition complète, amélioration significative ou amélioration partielle de l’épiphora. L'absence de modification ou l'aggravation de l’épiphora comparativement à la période préopératoire étaient considérées comme un échec de la chirurgie. RésultatsUn total de 77 chirurgies (53 patients) réalisées sous DSG ont été incluses. On a noté 14 cas (18,2 %) de retard de l’écoulement de type « pré-sac » et 63 cas (81,8 %) de retard de type « post-sac ». Le taux de réussite chirurgicale dans l'ensemble de la cohorte a été de 83,1 %. Le taux de réussite a atteint 100 % dans le groupe « pré-sac » et 79,4 % dans le groupe « post-sac » (p = 0,06). Le suivi moyen a été de 22 mois (é.-t. : 21 mois). ConclusionNous avons été en mesure d’établir l'utilité de la DSG dans la planification du traitement chirurgical de l’épiphora fonctionnel. Comparativement à l'intubation lacrymale empirique ou à la dacryocystorhinostomie, la démarche reposant sur la DSG peut être particulièrement utile dans l’épiphora fonctionnel de type « pré-sac ».

Diagnostic value of lacrimal scintigraphy in the evaluation of lacrimal drainage system obstruction: a systematic review and meta-analysis.

A systematic review and meta-analysis to evaluate the diagnostic performance of lacrimal scintigraphy (LS) versus anatomical methods in the evaluation of the nasolacrimal duct obstruction (NLDO). A systematic search was performed using electronic bibliographic databases until the end of May 2021. Inclusion criteria: (a) used LS as a diagnostic method to evaluate NLDO; (b) used anatomical studies [including syringing, irrigation, probing, and dacryocystography (DCG)] as reference tests; and (c) provided adequate crude data. A hierarchical method was used to pool the sensitivity and specificity. The hierarchical summary receiver-operating characteristic model was performed. Additionally, the studies' heterogeneity and publication bias were analyzed. All analyses were conducted by the 'Midas' module of STATA 16. Twelve articles (with 14 separate populations) were considered eligible to enter the meta-analysis. They were divided into two groups based on the reference standard method, called irrigation and DCG groups. In the irrigation group, the pooled sensitivity and specificity were 89% [95% confidence interval (CI), 72-96%] and 25% (95% CI, 8-56%), respectively. In DCG group, the pooled sensitivity and specificity were 97% (95% CI, 85-100%) and 27% (95% CI, 0.12-0.49), in turn. LS is a sensitive modality to evaluate the anatomical obstruction of NLD. In contrast, it shows low pooled specificity compared with anatomical methods. Thus, LS can be used as the first noninvasive modality for the evaluation of epiphora. However, in case of any abnormality, confirmatory procedures are required.

Syringing has limited reliability in differentiating nasolacrimal duct stenosis from functional delay

PurposeTo elucidate the role of syringing in assessing nasolacrimal duct (NLD) stenosis and non-anatomical functional NLD delay.MethodsConsecutive adult patients with epiphora attending a tertiary lacrimal clinic from June 2011 to March 2021 were reviewed. Cases with evidence of canalicular stenosis or other identifiable causes of epiphora were excluded. Following syringing, patients were investigated with dacryocystography (DCG) and dacryoscintigraphy (DSG). The sensitivity and specificity of syringing were evaluated using the combined findings on DCG and DSG.ResultsA total of 289 symptomatic lacrimal systems (197 patients; mean age 65.5 ± 14.9 years, 66% females) were included. More than one-third of cases with both normal DCG and DSG were noted to have some degree of reflux on syringing (specificity = 65.1%, 95% CI 50.2–77.6%). The sensitivities were considerably low for NLD stenosis (i.e., stenosis on DCG and delay on DSG) and for functional NLD delay (i.e., normal DCG and delay on DSG), of which 43.7% (95% CI 32.2–55.9%) and 54.3% (95% CI 45.7–62.7%) had full patency on syringing, respectively (p = 0.17).ConclusionsFull patency on syringing was unreliable for ruling out NLD stenosis and functional delay. Furthermore, a positive syringing may be associated with functional NLD delay and cannot reliably differentiate it from stenosis.

Determination of the Radiation Dose Level Emitted to the Environment in Patients Undergoing Dacryo Scintigraphy

In this study, the radiation dose rates emitted by patients who underwent dacryoscintigraphy imaging were determined. For this, the radiation dose rate was measured at the 8.23, 41.68 and 56.81 minutes after the injection of the radiopharmaceutical. In addition, 12 points were determined from the front of the patient. these points are 25, 50, 100 and 200 cm from the head level, 25, 50, 100, and 200 cm from the chest level and 25, 50, 100 and 200 cm from the foot level. 36 different measurements were made from one patient, at 3 different times, from these points. As a result of the measurements, the average dose rate varies according to time and measurement point and was found between 0.22 µSh-1 and 2.86 µSh-1.

A Comparison of Transcanalicular, Endonasal, and External Dacryocystorhinostomy in Functional Epiphora: A Minimum Two-Year Follow-Up Study.

Purpose To compare the outcomes of transcanalicular diode laser-assisted dacryocystorhinostomy (TCL-DCR), nonendoscopic endonasal dacryocystorhinostomy (NEN-DCR), and external dacryocystorhinostomy (EXT-DCR) as first-line treatments for functional epiphora. Methods This multicenter, retrospective, case-control study included 135 eyes of 135 patients with functional epiphora (86 females and 49 males). Functional epiphora was diagnosed based on a patent lacrimal system with a delay in the fluorescein dye disappearance test (FDDT) or dacryoscintigraphy (DSG) and no ocular surface or eyelid abnormalities. The patients were treated with TCL-DCR (2008–2011) or Ext-DCR (2005–2008, 2011–2017) at Beyoglu Eye Research Hospital (Istanbul, Turkey) and NEN-DCR at Carrot Eye Surgery Clinic affiliated with the McMaster University (Hamilton, ON, Canada) (2010–2016). Success was defined as the absence of epiphora and the normalization of an earlier delayed FDDT after surgery. Results The TCL-DCR, NEN-DCR, and EXT-DCR groups consisted of 38, 47, and 50 eyes with 25.9, 44.2, and 45.9 months of follow-up. The success rate for TCL-DCR was 65.8%, 70.2% for NEN-DCR, and 84.0% for EXT-DCR. During the follow-up period, 13.2% of TCL-DCR cases and 6.4% of NEN-DCR cases developed an anatomic obstruction of the lacrimal system. Conclusion The EXT-DCR group had a higher success rate in the management of functional epiphora than the NEN-DCR and TCL-DCR groups and was significantly safer in terms of an iatrogenic anatomic block of the lacrimal system.

Lacrimal imaging findings in fellow asymptomatic eyes of unilateral epiphora.

To investigate the prevalence of subclinical anatomical and functional abnormalities of lacrimal drainage in fellow asymptomatic eyes of unilateral epiphora using dacryocystography and dacryoscintigraphy. Retrospective case note review of lacrimal imaging of adult patients presenting to a hospital Oculoplastic clinic with unilateral epiphora over 10 years. A total of 172 patients with unilateral epiphora were included. The median age was 67 (range 18-96 years). A dacryoscintigraphy (DSG) abnormality was present in 54 (42%) asymptomatic eyes, and dacryocystography (DCG) abnormality in 10 (10%). The most common finding on DSG was no delay in 76 eyes (58%), and most common DSG abnormality was post sac delay in 51 (39%) eyes. The most common finding on DCG was no obstruction in 88 (90%) eyes, and the most common DCG abnormality was post sac stenosis (7.1%). Of the 92 asymptomatic eyes with both DCG and DSG, 53 (57%) showed neither an obstruction on DCG or delay on DSG, and 28 (30%) showed a post sac delay on DSG and no abnormality on DCG. Greater than a third of asymptomatic eyes displayed post sac delay on DSG, frequently without accompanying anatomical obstruction on DCG. Subclinical DSG delay in asymptomatic eyes may represent physiological variation in tear transit time, subclinical lacrimal drainage dysfunction or anatomical stenosis undetected by DCG. Furthermore, the DSG results of fellow asymptomatic eyes in unilateral epiphora may not represent a normal standard that can be utilised for comparison. Further investigation with dacroyendoscopy, the use of control eyes, and long term follow up is required.

Modern methods in diagnostics of lacrimal system vertical part obliteration

A review of the literature is devoted to the description of modern diagnostic methods that are directed at detecting lacrimal pathway obstruction. The presented analysis is based on the study of data from Russian and foreign literary sources on both routine and high-tech lacrimal system examination methods, as well as on authors' experience in studying the diagnostic efficiency of imaging methods such as lacrimal scintigraphy, computed tomography with lacrimal pathway contrasting, and also single photon emission computed tomography. The article gives information about the advantages and disadvantages of the presented methods, highlights the questions of the prospects of their usage in practical dacryology.

Lacrimal scintigraphy BNMS Guidelines.

The purpose of this guideline is to assist specialists in Nuclear Medicine and Radionuclide Radiology in recommending, performing, interpreting and reporting the results of lacrimal scintigraphy (also known as Dacroscintigraphy). This guideline will assist individual departments to formulate their own local protocols. This does not aim to be prescriptive regarding technical aspects of individual camera acquisitions, which need to be developed in conjunction with the local experts in medical physics. There are numerous radiological techniques to assess the physiology of the lacrimal system. This guideline will describe the application of a drop of radiotracer into each eye and consecutive imaging to demonstrate the level of impaired drainage, with the possibility of quantifying such impairment. This guideline is a recent and updated version of a previously published guideline on the British Nuclear Medicine Society website in 2018 [1].

Correlation Between Lacrimal Syringing Test and Dacryoscintigraphy in Patients With Epiphora.

The purpose of this study was to evaluate the correlation between the lacrimal syringing test (LST) and dacryoscintigraphy (DSG) in patients with epiphora. The authors retrospectively reviewed the clinical records of patients who underwent both LST and DSG from March 2016 to February 2018. From this, 636 eyes of 336 patients with a mean age of 61.20 ± 11.93 years (range, 22-86 years) were included. The concordance rate between LST and DSG was 43.7% (278 eyes). The sensitivity of DSG was 68.78%, and specificity was 30.99%. Factors of age and sex were analyzed in terms of concordance. The authors categorized age into 2 groups of younger and older than 65 years. Only sex was found to affect the results, with a much higher concordance rate in the female group than the male group. The lack of correlation between the tests indicates that the LST and DSG methods are complementary to each other. There is no single reliable method for testing patency of the lacrimal drainage system. Therefore, physicians should refer to these tests as complementary in a clinic setting.

Comparison of a manometric tear duct irrigation test with dacryoscintigraphy in the investigation of epiphora

ABSTRACT Purpose 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. Methods 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. Results 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). Conclusions In contrast to DSG, the mTDT provides valuable, objective information on lacrimal resistance that can guide a decision to DCR surgery.

Clinical utility of SPECT/CT and CT-dacryocystography-enhanced dacryoscintigraphy in the imaging of lacrimal drainage system obstruction

PurposeEpiphora is commonly caused by a relative or complete occlusion in the lacrimal drainage system (LDS), principally a nasolacrimal duct obstruction (NLDO). Dacryoscintigraphy (DSG), an extensively assessed imaging technique in diagnosing its abnormalities, can provide only planar images, according to which it needs to be improved. Our aim was to evaluate clinical utility of simultaneous DSG and single-photon emission computed tomography/computed tomography (SPECT/CT) combined with computed tomographic dacryocystography (CT-DCG) in the evaluation of LDS.MethodsDynamic imaging with DSG was performed, and tracer radioactivity was detected by a gamma camera. Successively, SPECT/CT images of the involved region were gained, followed by CT-DCG, during which a contrast medium was syringed into the affected LDS, and finally contrast CT scans were obtained again from the same region.ResultsFifty-seven patients, mean age 54.25 (± 18.26) years all with unilateral NLDO and 32 control subjects, all with patent LDS, mean age 49.88 (± 18.61) years were evaluated in the study. Delayed outflow of tearing eyes was exposed to DSG compared to the fellow and control eyes. The highest value for sensitivity was observed for SPECT/CT, followed by CT-DCG and DSG techniques, while combining DSG with SPECT/CT, DSG with CT-DCG, and SPECT/CT with CT-DCG, the sensitivity increased to 96.49%, 92.98%, and 94.73%, respectively.ConclusionsAlthough DSG is a sensitive nuclear medicine method, it only provides useful clinical data when simultaneously supplemented with SPECT/CT and CT-DCG trials as they jointly can offer valuable information about the localization of an abnormality and verify stenosis or obstruction.

Evaluation of the tear clearance rate by dacryoscintigraphy in patients with obstructive meibomian gland dysfunction

PurposeTo measure tear clearance values in patients with meibomian gland dysfunction (MGD) with a dynamic nuclear medicine method, namely, dacryoscintigraphy (DSCI). MethodsTwenty-four MGD patients and 24 healthy volunteers were examined. During DSCI one drop of a solution with 100 MBq/mL99mTc sodium pertechnetate was instilled with a micropipette into the lacrimal lake of both eyes. Measurements were performed according to a dynamic data acquisition protocol, which resulted in summed DSCI images. Data were also evaluated separately in special regions of interest (ROI), and consecutive time activity curves were created. Tear clearance (T½) values were calculated based on the activity curves. In addition, tear osmolarity measurements, tear breakup time (tBUT), and Schirmer I (STI) tests were performed prior to DSCI examination. ResultsThe T½ values were 29.91 ± 11.61 min in MGD patients and 6.26 ± 1.5 min in healthy controls. Tear osmolarity parameters were 308 ± 9.41 mOsm/L and 288.9 ± 6.4 mOsm/L, tBUT values were 5.54 ± 2.73 s and 11.4 ± 2.7 s, while the STI test values were 6.17 ± 2.78 mm and 13.58 ± 3.8 mm, respectively. The differences were significant (p < 0.01) in all cases. ConclusionsAlthough the MGD patients’ lacrimal drainage systems were patent their tear clearance values were significantly higher than those of healthy volunteers, which may be caused by decreased drainage of tears from the eyes towards the nasal cavity. The understanding of new features regarding the altered physico-chemical characteristics of MGD tears has been augmented by the results of this study.

How reliable is the lacrimal scintigraphy report? An inter-observer agreement and reliability study.

To assess the inter-observer agreement and reliability as well as intra-observer repeatability for lacrimal scintigraphy (LS) reports with and without considering the irrigation test results. A prospective, observational, cross sectional study. Two masked clinicians (lacrimal surgeon and nuclear medicine specialist) independently reported 100 LS images (50 patients of >6 years of age with unilateral anophthalmic socket) in a university hospital. The lacrimal surgeon performed a diagnostic irrigation test and repeated the report of the same LS images 2y after the first report (intra-observer agreement). A weighted Kappa analysis was performed to determine inter-observer agreement and reliability as well as intra-observer repeatability for the type (normal, partial and complete obstruction) and location (presac, preduct, and intraduct) of the obstruction. Subgroup analysis was also performed with consideration of irrigation test results. A significantly moderate agreement was found between lacrimal surgeon and nuclear medicine specialist for both the type (Kappa=0.55) and location (Kappa=0.48) of obstruction. Agreement values were higher for the type (Kappa=0.61 vs 0.41) and location (Kappa=0.56 vs 0.31) of obstruction in cases with normal than abnormal irrigation test. Strong and significant intra-observer (lacrimal surgeon) repeatability was found for both the type (Kappa=0.66) and location (Kappa=0.69) of obstruction. LS showed no to slight reliability based on irrigation test. A moderate agreement is found between lacrimal surgeon and nuclear medicine specialist regarding the interpretation of LS suggesting the importance of consensus groups among nuclear medicine specialists and lacrimal surgeons to create a common language for interpretation of LS. Intra-observer repeatability is strong for the lacrimal surgeon.

Development of Predictive Models in Patients with Epiphora Using Lacrimal Scintigraphy and Machine Learning.

We developed predictive models using different programming languages and different computing platforms for machine learning (ML) and deep learning (DL) that classify clinical diagnoses in patients with epiphora. We evaluated the diagnostic performance of these models. Between January 2016 and September 2017, 250 patients with epiphora who underwent dacryocystography (DCG) and lacrimal scintigraphy (LS) were included in the study. We developed five different predictive models using ML tools, Python-based TensorFlow, R, and Microsoft Azure Machine Learning Studio (MAMLS). A total of 27 clinical characteristics and parameters including variables related to epiphora (VE) and variables related to dacryocystography (VDCG) were used as input data. Apart from this, we developed two predictive convolutional neural network (CNN) models for diagnosing LS images. We conducted this study using supervised learning. Among 500 eyes of 250 patients, 59 eyes had anatomical obstruction, 338 eyes had functional obstruction, and the remaining 103 eyes were normal. For the data set that excluded VE and VDCG, the test accuracies in Python-based TensorFlow, R, multiclass logistic regression in MAMLS, multiclass neural network in MAMLS, and nuclear medicine physician were 81.70%, 80.60%, 81.70%, 73.10%, and 80.60%, respectively. The test accuracies of CNN models in three-class classification diagnosis and binary classification diagnosis were 72.00% and 77.42%, respectively. ML-based predictive models using different programming languages and different computing platforms were useful for classifying clinical diagnoses in patients with epiphora and were similar to a clinician's diagnostic ability.

Functional success evaluation of lacrimal drainage system by dacryoscintigraphy after transcanalicular diode laser dacryocystorhinostomy.

Purpose:The purpose of the study was to evaluate the functional success rates using dacryoscintigraphy (DSG) after transcanalicular diode laser dacryocystorhinostomy (TDL-DCR).Methods:In this retrospective study, we investigated the records of 56 patients who underwent TDL-DCR for unilateral primary acquired nasolacrimal duct obstruction and anatomic patency was achieved. The lacrimal drainage systems of the other eyes of the patients were normal and were selected as control group. The functional success was evaluated with tear transit time (TT) on DSG and epiphora complaints’ score (ECS) at postoperative 6 months.Results:Twenty-two (39%) of the patients were male and 34 (61%) were female, with a mean age of 46.6 (21–64). The dacryoscintigraphic findings of the operated and healthy eyes showed that there was statistically insignificant prolongation in the tear TT at the operated side at postoperative 6th month (P > 0.05). The mean ECS of operated eyes was 0.89. Functional success was achieved in 43 (76.8%) patients when the ECS of 0 and 1 was accepted as successful. A statistically significant delay in drainage was observed in DSG in all of the cases with epiphora score of 2 and 3 (P < 0.05). The tear TT was prolonged with the age increase (P < 0.05), but there was no significant difference concerning the gender.Conclusion:DSG is an effective tool to evaluate the functional success of TDL-DCR.

Dacryoscintigraphy: A Pictorial Essay.

Dacryoscintigraphy is a noninvasive, simple, easy to perform imaging modality used in the evaluation of epiphora. However, it is an infrequently done study in nuclear medicine departments. A standardized protocol and a systematic interpretation of the scans help in answering the queries of the clinicians in cases of epiphora. We have attempted to build a pictorial essay of the various findings detected on dacryoscintigraphy.