scRNA-Seq: First Atlas and Cellular Landscape of Lacrimal Sac: Implications in Primary Acquired Nasolacrimal Duct Obstruction Pathogenesis.

Purpose: The aim of this study was to describe the transcriptional changes of individual cellular components in the lacrimal sac in patients with primary acquired nasolacrimal duct obstruction (PANDO) and attempt to construct the first lacrimal sac cellular atlas to elucidate the potential mechanisms that may drive the disease pathogenesis. Methods: Lacrimal sac samples were obtained intra-operatively during the endoscopic dacryocystorhinostomy (EnDCR) procedure from five patients. Single-cell RNA sequencing was performed to analyze each individual cell population including epithelial and immune cells during the early inflammatory and late inflammatory phases of the disease. Results: Eleven cell types were identified among 25,791 cells. T cells and B cells were the cell populations with the greatest variation in cell numbers between the two phases and were involved in immune response and epithelium migration-related pathways. The present study showed that epithelial cells highly expressed the genes of senescence-associated secretory phenotype (SASP) and were involved in influencing the inflammation, neutrophil chemotaxis, and migration during the late inflammatory stage. Enhanced activity of CXCLs-CXCRs between the epithelial cells and neutrophils was noted by the cell-cell communication analysis and is suspected to play a role in inflammation by recruiting more neutrophils. Conclusions: The study presents a comprehensive single-cell landscape of the lacrimal sac cells in different phases of PANDO. The contribution of T cells, B cells, and epithelial cells to the inflammatory response, and construction of the intercellular signaling networks between the cells within the lacrimal sac has further enhanced the present understanding of the PANDO pathogenesis.

Etiopathogenesis of primary acquired nasolacrimal duct obstruction (PANDO).

Primary acquired nasolacrimal duct obstruction, or PANDO, is a common adult lacrimal drainage disorder. The current treatment modality of dacryocystorhinostomy to bypass the obstructed nasolacrimal duct has excellent outcomes. However, the understanding of the disease etiopathogenesis needs to be revisited. There are not many studies that specifically assessed any hypothesis or ones that convincingly put forth the presumed or confirmed interpretations regarding the PANDO pathogenesis or the mechanisms or pathways involved therein. Histopathological evidence points to recurrent inflammation of the nasolacrimal duct, subsequent fibrosis, and the resultant obstruction. The disease etiopathogenesis is considered multifactorial. Several implicated suspects include anatomical narrowing of the bony nasolacrimal duct, vascular factors, local hormonal imbalance, microbial influence, nasal abnormalities, autonomic dysregulation, surfactants, lysosomal dysfunction, gastroesophageal reflux, tear proteins, and deranged local host defenses. The present work reviewed the literature on the etiopathogenesis of primary acquired nasolacrimal duct obstruction (PANDO) to gain insights into the present state of the understanding and the high-value translational implications of precisely decoding the disease etiology.

Obstruction of the Tear Drainage Altered Lacrimal Gland Structure and Function.

Purpose: Orbital glands and drainage conduits are two distinct entities that constitute the lacrimal apparatus system, the malfunction of which leads to a range of ocular surface disorders. Despite the close functional relationship, how the two parts interact under pathophysiological conditions has not been directly tested. The study aims to investigate the lacrimal gland (LG) structural and functional changes upon the drainage system obstruction, thus, testing their function link. Methods: Dacryocystectomy was performed in C57BL/6 mice to create a surgical model for tear duct (TD) obstruction (STDOB). Prickle1 mutant line with congenital nasolacrimal duct dysplasia serves as a genetic model for TD obstruction (GTDOB). Alterations of the LG and the ocular surface in tear duct obstruction mice were examined. Results: STDOB and GTDOB mice showed similar ocular surface phenotypes, including epiphora, corneal epithelial defects, and conjunctival goblet cell abnormalities. At the molecular and cellular levels, aberrant secretory vesicle fusion of the LG acinar cells was observed with altered expression and localization of Rab3d, Vamp8, and Snap23, which function in membrane fusion. LG secretion was also altered in that lactoferrin, lipocalin2, and lysozyme expression were increased in both LG and tears. Furthermore, STDOB and GTDOB mice exhibited similar LG transcription profiles. Conclusions: Physical obstruction of tear drainage in STDOB or GTDOB mice leads to LG dysfunction, suggesting a long-distance interaction between the tear drainage conduits and the LG. We propose that various components of the lacrimal apparatus should be considered an integral unit in diagnosing and treating ocular surface diseases.

Involvement of Laryngopharyngeal Reflux in Ocular Diseases: A State-of-the-Art Review.

BACKGROUND: Laryngopharyngeal reflux-associated symptoms embrace a wide variety of head and neck manifestations. Its participation in eye disorders has recently been postulated, and there is currently no consensus in this regard. The aim of this manuscript is to review the role of reflux in the development of ocular signs and symptoms, and its physio-pathological mechanisms. METHODS: A systematic approach based on the preferred reporting Items for a systematic review and meta-analysis checklist with a modified population, intervention, comparison, and outcome framework was used to structure the review process of studies that evaluated the possible association, with clear diagnostic methods, of laryngopharyngeal reflux and ocular signs and symptoms. Search was conducted in different indexed databases (PubMed/MEDLINE, the Cochrane Library, Scielo and Web of Science) and through the meta-searcher Trip Database with the keywords: reflux, laryngitis, laryngopharyngeal, gastroesophageal, ocular, eye, symptoms, signs, conjunctivitis, keratitis, dacryocystitis, dry eye. RESULTS: Seven studies met the inclusion criteria, in which the primary acquired nasolacrimal duct obstruction and the ocular surface disease were evaluated. The local increase of eye pepsin concentration (>2.5 ng/mL) may affect ocular surface though its direct proteolytic activity and the local expression of proinflammatory cytokines. The H. Pylori, with a similar mechanism to reach the lacrimonasal duct, would be associated with the release of proinflammatory and vasoactive substances that would lead to a mucosa injury and chronic inflammation. Ocular Surface Disease Index seems to correlate directly with the reflux severity, with cut-off of 41.67 score as predictor for disease. DISCUSSION: The role of laryngopharyngeal reflux in the development of ocular disorders has not yet been demonstrated and data are limited and heterogeneous. It seems theoretically conceivable that pepsin may reach lachrymal duct area through hypopharyngeal-nasal gaseous reflux events. Future studies using objective testing for diagnosis and pepsin detection into the tear and nasal mucosa are needed in order to explore this potential relationship.

High-risk HPV-related Squamous Cell Carcinoma in the Conjunctiva and Lacrimal sac: Clinicopathologic Characteristics and Diagnostic Utility of p16 and Rb Immunohistochemistry.

High-risk human papillomavirus (HPV) infection in conjunctival and lacrimal sac squamous cell carcinomas (SCCs) has been sporadically reported; however, its prevalence, clinicopathologic significance and surrogate markers have not been fully elucidated. Here, we attempted to clarify these questions in Japanese patients with conjunctiva and lacrimal sac SCCs. We retrospectively collected 51 conjunctival SCC and 7 lacrimal sac SCC samples and analyzed them for (1) transcriptionally active high-risk HPV infection using messenger RNA in situ hybridization and (2) protein expressions of p16 and Rb using immunohistochemistry (IHC). Among a total of 58 cases, 25 (43.1%) and 16 (27.6%) tumors were positive for p16-IHC and HPV in situ hybridization, respectively. Ten (19.6%) of the 51 conjunctival SCCs, especially in the palpebral conjunctiva, and 6 (85.7%) of the 7 lacrimal sac SCCs were positive for high-risk HPV. High-risk HPV infection was significantly associated with younger patients, nonkeratinizing SCC histology, p16-positivity and partial loss of Rb expression, but not with recurrence risk. Notably, p16-IHC was not a perfect surrogate marker for high-risk HPV infection; only 64% (16/25) of p16-positive tumors were positive for high-risk HPV. In contrast, the p16+/Rb partial loss pattern was exclusively correlated with high-risk HPV-positivity. The results suggest that the combination of p16 and Rb expression patterns by IHC could be a useful method to predict high-risk HPV infection in conjunctival and lacrimal sac SCCs. HPV infection may be of less prognostic value in this field of cancers.

Na+/I- symporter expression, function, and regulation in non-thyroidal tissues and impact on thyroid cancer therapy.

For the past 80 years, radioiodine (131I) has been used to ablate thyroid tissue not removed by surgery or to treat differentiated thyroid cancer that has metastasized to other parts of the body. However, the Na+/I- symporter (NIS), which mediates active iodide uptake into thyroid follicular cells, is also expressed in several non-thyroidal tissues. This NIS expression permits 131I accumulation and radiation damage in these non-target tissues, which accounts for the adverse effects of radioiodine therapy. We will review the data regarding the expression, function, and regulation of NIS in non-thyroidal tissues and explain the seemingly paradoxical adverse effects induced by 131I, the self-limited gastrointestinal adverse effects in contrast to the permanent salivary dysfunction that is seen after 131I therapy. We propose that prospective studies are needed to uncover the time-course of pathological processes underlying development and progression or ultimate resolution of 131I-induced salivary ductal obstruction and nasolacrimal duct obstruction. Finally, preventive measures and early therapeutic interventions that can be applied potentially to eliminate or alleviate long-term radioiodine adverse effects will be discussed.

Clinical and Demographic Characteristics of Tearing in Patients after Radioiodine Ablation for Differentiated Thyroid Cancer.

Background: Radioiodine ablation is a frequent procedure for the management of thyroid cancer. In several cases, this treatment is followed by secondary acquired nasolacrimal duct obstruction (SALDO). Risk factors for the development of SALDO are not defined yet.Aim - to provide clinical and demographic characteristics of tearing in patients after radioiodine treatment.Materials and methods: Material was obtained by a phone survey of 588 patients who underwent radioiodine treatment. Age and gender of the respondent, strength of administered medication, and time since the end of treatment were taken into account. Patients were asked if they had dry mouth and/or tearing at the time of the survey. Differences in values were found using parametric and nonparametric criteria, Pearson's χ2 test. Differences were considered statistically significant at p ≤ 0.05.Results: Severe tearing was reported by 8.8% of patients after single-dose radioiodine treatment and 23.9% of patients after repeated one. The age of patients with severe tearing and without it showed statistically significant difference in patients after single-dose radioiodine treatment and no statistically significant difference in patients after repeated radioiodine treatment. Administration of 4 GBq or more in patients aged 61-71 years results in 4-fold increase of the risk of severe tearing. Dry mouth causes 3.6-fold increase of the risk of developing severe tearing.Conclusion: Finding risk factors for SALDO development after radioiodine therapy in the future will contribute to an individualized approach to the prevention of this complication. Development of preventive measures is one of the tasks facing researchers.

Detection & analysis of inflammatory cytokines in tears of patients with lacrimal duct obstruction.

Background & objectives: Tear proteomic changes can be a candidate etiopathogenesis of lacrimal duct obstruction diseases (LDODs). Studies on proteomics have focused primarily on nasolacrimal duct obstruction, and some specific inflammatory cytokines such as interferon (IFN)-α2a, interleukin (IL)-8 and IL-10, have not been investigated. In addition, differences in inflammatory cytokines in tears according to the LDOD subtype have not been reported. This study aimed to quantitatively compare inflammatory cytokines in tears from patients with LDOD and investigate tear-cytokine differences among different LDOD subtypes. Methods: Tear samples were collected from both eyes of 30 patients with unilateral LDOD: five patients with prelacrimal obstruction, five with acute dacryocystitis and 20 with chronic dacryocystitis. The contralateral eyes were used as controls. IFN-α2a, IFN-ß, IFN-γ, IL-17A, IL-6, IL-8, tumour necrosis factor-alpha (TNF-α), vascular endothelial growth factor (VEGF)-A, induced protein-10 (IP-10) and monocyte chemotactic protein-1 (MCP-1) were quantified in all samples. Results: The expression of eight cytokines (except for IP-10 and MCP-1) were significantly increased in the affected eyes compared with those in the control eyes. The levels of nine inflammatory cytokines (except for IP-10) in the affected eyes of patients with chronic dacryocystitis were higher than those in the affected eyes of patients with prelacrimal obstruction. In addition, patients with chronic dacryocystitis presented significantly higher IFN-γ level than those with prelacrimal obstruction or acute dacryocystitis. Interpretation & conclusions: Specific pro-inflammatory cytokines were increased in tears of patients with LDOD compared with those in the controls. The specific cytokine profiles observed in the tears of individuals with different LDOD subtypes may be associated with the unique aetiopathogenesis of these conditions.

The spectrum of 124I uptake in the lacrimal gland and nasolacrimal sac/duct on PET/CT imaging.

METHODS: 124I PET/CT in 31 DTC patients was performed at 2, 24, 48, 72, and 96 h after oral administration of 31.5 or 62.9 MBq (0.85 or 1.7 mCi) of 124I after either recombinant human thyroid-stimulating hormone injections or thyroid hormone withdrawal. All but two patients had a history of prior 131I therapy. Patterns of 124I uptake in the lacrimal glands and nasolacrimal sac/ducts (NLD) were assessed. RESULTS: A total of 173 individual 124I PET/CT scans (forming 35 sets of scans) were reviewed for 31 patients. Lacrimal glands were visualized bilaterally in only 4 patients. The focal mild uptake (grade 2), best seen on the 2-h images, was crescent-shaped and located in the lateral upper quadrant of the orbit. In contrast, the NLDs were identified in all patients (bilateral in 29 of 31 patients) with high focal uptake (grade 4) peaking on the 2- and 24-h timepoints; however, the overall pattern of uptake was variable. Of the 29 patients with prior 131I therapy, three patients had a relatively fixed and unchanging pattern of uptake on at least one side of the NLDs. CONCLUSIONS: In patients with DTC, 124I activity in the NLDs is more frequently visualized, more intense, more prolonged, and more variable than in the lacrimal glands. The lack of clearance may suggest possible obstruction or stasis of an NLD.

Alpha-Adrenergic Agonists Stimulate Fluid Secretion in Lacrimal Gland Ducts.

Purpose: The role of adrenergic innervation in the regulation of lacrimal gland (LG) ductal fluid secretion is unknown. The Aim of the present study was to investigate the effect of adrenergic stimulation on fluid secretion in isolated LG duct segments and to study the underlying intracellular mechanisms. Methods: Fluid secretion of isolated mouse LG ducts was measured using video-microscopy. Effect of various adrenergic agonists (norepinephrine, phenylephrine, and isoproterenol) on fluid secretion as well as inhibitory effects of specific antagonists on adrenergic agonist-stimulated secretory response were analyzed. Changes in intracellular Ca2+ level [Ca2+i] were investigated with microfluorometry. Results: Both norepinephrine and phenylephrine initiated a rapid and robust fluid secretory response, whereas isoproterenol did not cause any secretion. Phenylephrine-induced secretion was completely blocked by α1D-adrenergic receptor blocker BMY-7378. The endothelial nitric oxide synthase (eNOS) inhibitor L-NAME or guanylyl cyclase inhibitor ODQ reduced but not completely abolished the phenylephrine-induced fluid secretion, whereas co-administration of Ca2+-chelator BAPTA-AM resulted in a complete blockade. Phenylephrine stimulation induced a small, but statistically significant elevation in [\(Ca_i^{2 + }\)]. Conclusions: Our results prove the direct role of α1-adrenergic stimulation on LG ductal fluid secretion. Lack of isoproterenol-induced fluid secretory response suggests the absence of ß-receptor mediated pathway in mouse LG ducts. Complete blockade of phenylephrine-induced fluid secretion by BMY-7378 and predominant inhibition of the secretory response either by L-NAME or ODQ suggest that α-adrenergic agonists use the NO/cGMP pathway through α1D receptor. Ca2+ signaling independent from NO/cGMP pathway may also play an at least partial role in α-adrenergic induced ductal fluid secretion.

CHARGE syndrome without colobomas: Ophthalmic findings.

To report ophthalmic findings of patients without colobomas, and with a clinical and molecular diagnosis of CHARGE Syndrome. Retrospective study of ophthalmic findings in 67 CHARGE patients-clinically confirmed diagnosis with positive CHD7 mutation-seen in the Ophthalmology department of Cincinnati Children's Hospital Medical Center between January 1, 2008 through September 25, 2018. Criteria for inclusion in this study was absence of any form of a coloboma in either eye. In our cohort, all patients had a positive CHD7 mutation, in addition to a clinical diagnosis. 19.4% (13/67) of CHARGE patients did not have a coloboma in either eye. 69.2% (9/13) had strabismus, 76.9% (10/13) had a refractive error that warranted refractive correction, 23.1% (3/13) had amblyopia, 38.5% (5/13) had nasolacrimal duct obstruction, 30.8% (4/13) had dry eye syndrome and exposure keratopathy, 15.4% (2/13) had ptosis, 15.4% (2/13) had blepharitis, 15.4% (2/13) had Cortical Visual Impairment, 7.7% (1/13) of patients had optic nerve drusen, 7.7% (1/13) had Marcus Gunn Jaw Winking, and 7.7% (1/13) with an eyelid nevus. There are numerous ophthalmic findings in individuals with CHARGE Syndrome without colobomas. No study to date has evaluated the ophthalmic findings in CHD7 positive CHARGE patients without colobomas. These findings need to be assessed and treated to ensure optimal vision in the CHARGE patient population. Absence of coloboma does not rule out a diagnosis of CHARGE syndrome, and if there is a clinical suspicion, clinical confirmation then genetic testing would be warranted.

Alteration of Tear Cytokine Expressions in Primary Acquired Nasolacrimal Duct Obstruction - Potential Insights into the Etiopathogenesis.

Purpose: To investigate the presence and level of 35 distinct cytokines in the tear fluid obtained from patients with primary acquired nasolacrimal duct obstruction (PANDO) and compare it with controls in an effort to understand the disease etiopathogenesis.Methods: Standard protocols were used for collecting tears from 60 eyes (20 diseased eyes and 20 healthy fellow eyes of unilateral PANDO, 20 control eyes of healthy subjects). A total of 35 analytes involved in inflammation, angiogenesis and wound healing were assessed by multiplex ELISA. Alterations in the tear levels of cytokines in PANDO and their comparison with the levels in the non-diseased fellow eye and healthy volunteers were noted. STRING analysis was used to assess the involved biological pathways of the altered cytokines. Linear mixed effect model was used for statistical analysis. A P value of <0.05 was considered significant.Results: There was significant upregulation of 10 pro-inflammatory cytokines in tears from diseased eyes of PANDO patients in comparison with the non-diseased controls and include matrix metalloproteinase 9 (MMP 9), serpin E1, Interleukin-6 (IL-6), hepatocyte growth factor (HGF), vascular endothelial growth factor-A and R2 (VEGF-A, VEGF R2), platelet-endothelial cell adhesion molecule (PECAM-1), c-reactive protein (CRP), chemokine ligand 2 (CCL2) and platelet-derived growth factor- AA (PDGF-AA). Amongst the anti-inflammatory cytokines, three were significantly upregulated in diseased eyes of PANDO patients in comparison with the non-diseased controls and include granulocyte-colony stimulating factor (G-CSF), retinol binding protein 4 (RBP4) and tissue inhibitor of metalloproteinases -1 (TIMP-1). There were no significant differences between the control eyes of the diseased patient and control eyes of healthy subjects. Based on the significantly altered cytokines, string analysis revealed that the biological pathways involved in the etiopathogenesis of PANDO include inflammation, angiogenesis, negative regulation of apoptosis, cellular proliferation and hormonal regulation.Conclusions: In cases of PANDO, dysregulation of certain cytokines was disease specific. Biological pathways reflect a possible link and interaction between the inflammatory cytokines with vasculature and hormonal microenvironments of the lacrimal drainage system, which in a way is bringing three promising candidates in the PANDO etiopathogenesis on a common ground.

Nasolacrimal stent with shape memory as an advanced alternative to silicone products.

Epiphora is the overflow of tears typically caused by obstruction or occlusion of the nasolacrimal duct. More attention is required to address this global health issue owing to the increase in air pollution. Implantation of a silicone stent is the preferred treatment for epiphora; however, introducing a silicone stent into a narrow duct with complex geometry is challenging as it requires guidance by a sharp metal needle. Additionally, silicone can cause adverse reactions such as biofilm formation and tear flow resistance due to its extreme hydrophobicity. To overcome these problems, in this study we developed a new type of biocompatible shape memory polymer (SMP) stent with elasticity capacity for self-expansion. First, SMPs in the form of x%poly(ε-caprolactone)-co-y%poly(glycidyl methacrylate) (x%PCL-y%PGMA) were synthesized via ring opening polymerization by varying the molar ratio of PCL (x%) and PGMA (y%). Second, the shape memory and mechanical properties were tuned by controlling the crosslinking degree and concentration of x%PCL-y%PGMA solution to produce a test type of SMP stent. Lastly, this 94%PCL-06%PGMA stent exhibited more standout critical functions in a series of in vitro and in vivo experiments such as a cell growth-supporting level of biocompatibility with nasal epithelial cells without significant inflammatory responses, better resistance to biofilm formation, and more efficient capacity to drain tear than the silicone control. Overall, 94%PCL-06%PGMA can be suggested as a superior alternative to the currently used materials for nasolacrimal stents. STATEMENT OF SIGNIFICANCE: Silicone intubation (stenting) has been widely used to treat nasolacrimal duct obstruction, however, it can cause adverse clinical effects such as bacterial infection; presents procedural challenges because of the curved nasolacrimal duct structure; and shows poor drainage efficiency stemming from the highly hydrophobic nature of silicone. In this work, we describe an innovative shape memory polymer (SMP) as a superior alternative to conventional silicone-based materials for nasolacrimal duct intubation. We demonstrate the clear advantages of the SMP over conventional silicone, including a much higher drainage capacity and superior resistance to bacterial infection.

Isolation and characterization of abundantly-expressed cDNAs from the Harderian gland of the garter snake (Thamnophis sirtalis: Colubridae).

The Harderian gland (HG) is an orbital structure whose proteinaceous secretions pass through the nasolacrimal duct to the vomeronasal organ (VNO). Though these three structures occur in many tetrapod vertebrates, the garter snake (Thamnophis sirtalis) is one of the few vertebrates in which the passage of the proteinaceous secretions have been experimentally shown. Secreted proteins from the HG may function as transporters for chemical signals to the VNO epithelium. To investigate the proteins being produced by the HG of the garter snake, cDNA libraries were constructed from HG mRNA, and several individual cDNAs were analyzed by sequencing, RT-qPCR, and PCR on genomic DNA. Two of the three cDNAs that were characterized are abundantly expressed only in the Harderian gland and contain putative signal sequences for secretion, which makes them candidates for transporter proteins secreted from the HG. One is a member of the large lipocalin family of proteins, based on its similarity to other members of that protein family. Many lipocalins are binding/carrier proteins for a variety of ligands. The other is a family of proteins, with five members identified so far, all of unknown structure and function and present in the garter snake genome but not in other squamate genomes.

Relationship between lacrimal sac size and duration of tearing in nasolacrimal duct obstruction.

OBJECTIVE: To analyze the relationship among the presence of lacrimal sac mucus retention, the vertical size of the lacrimal sac, and the duration of tearing symptom in patients with nasolacrimal duct obstruction (NLDO). DESIGN: Retrospective case series. PARTICIPANTS: We reviewed the medical records of 473 patients (664 eyes) who underwent external dacryocystorhinostomy for primary NLDO. METHODS: The information about the presence of lacrimal sac mucus retention and vertical size of the lacrimal sac lumen was collected intraoperatively. The vertical size of the lacrimal sac was classified into 3 groups: small (<5 mm), medium (5-10 mm), and large (>10 mm). The relationship between the lacrimal sac size, presence of mucus retention, and duration of tearing was analyzed. RESULTS: Of the 664 eyes, 138 had a small lacrimal sac, 199 had a medium lacrimal sac, and 327 had a large lacrimal sac. The distribution of the lacrimal sac size groups differed significantly between the eyes with (n = 245) and without (n = 419) mucus retention (p < 0.001). Among all the subjects of each lacrimal sac size group, there was no significant difference in the duration of symptoms (p = 0.176). However, in patients without mucus retention, the symptom duration in the small lacrimal sac group was significantly longer than that in the large lacrimal sac group (p = 0.017). CONCLUSIONS: In cases with mucus retention, a small lacrimal sac is rare. In cases without mucus retention, the duration of tearing symptom was significantly longer in small lacrimal sac group.

Surfactant proteins: Role in lacrimal drainage disorders.

Surfactants are complex mixtures of phospholipids and proteins produced by type II alveolar cells of the lungs and play a crucial role in pulmonary physiology. Six types of surfactant proteins (SP) are known; SP-A, SP-B, SP-C, SP-D, SP-G and SP-H. The major role of SP is in reducing surface tension and various immunological functions. SP-A, SP-B, SP-C and SP-D have been demonstrated in the tear film and the epithelium of the lacrimal sac (LS) and nasolacrimal ducts (NLD). All surfactant proteins except SP-G were also isolated from the canalicular tissues. The authors hypothesize that surfactant proteins play a significant role in the pathogenesis of lacrimal drainage disorders; functional nasolacrimal duct obstruction (FNLDO) and infective dacryocystitis.

Biopsy of recurrent nasolacrimal duct obstruction using sheath-guided dacryoendoscopy.

PURPOSE: The purpose of this article is to present a novel technique, as well the histopathological findings, of dacryoendoscopic guided nasolacrimal duct (NLD) biopsy for recurrent nasolacrimal duct obstruction (NLDO). METHODS: This study involved subjects with recurrent NLDO. Direct endoscopic probing or sheath-guided endoscopic probing was used for the initial intubation in all treated eyes, and the stent had been removed at between 2 and 11 months (mean 3.5 months) post-intubation with dacryoendoscopic confirmation of patency and mucosal regeneration. Biopsy specimens were obtained by scraping the recurrent lesion by sheath advancement. Histopathological examination and immunohistochemical (IHC) staining were performed. RESULTS: In five patients (two males and three females, mean age: 71.2 ± 5.6 years [range: 61-78 years]) with recurrent NLDO, biopsy specimens were obtained from six ducts of six eyes, and stratified epithelium and a mixed inflammatory cell infiltrates were identified. IHC staining was positive for cytokeratin (CK)4 and CK13, and negative for paired box protein Pax-6. CONCLUSIONS: This novel technique enabled a minimally invasive biopsy of the NLD to be obtained, and IHC staining indicated the presence of mucus epithelium, thus suggesting squamous metaplasia of the usual respiratory epithelium which likely occurs secondary to chronic inflammation.

Soluble glycoproteins of the lacrimal sac: role in defense with special reference to prolactin-inducible protein (PIP).

Purpose: Glycoproteins play an important role in human mucosal defenses and immunity-related cell-to-cell interactions. The aim of the present study is to investigate the presence and patterns of lacrimal sac glycoproteins involved in defense mechanisms with a special reference to prolactin-inducible protein (PIP). Methods: The study was performed on healthy lacrimal sacs obtained from exenteration samples immediately after surgery and frozen at -80 degrees for subsequent analysis. Four lectins namely Concanavalin A (Con A), Dolichos lablab lectin (DLL), Wheat Germ agglutinin (WGA), and Momordica charantia lectin (MCL) were purified by affinity chromatography. Soluble proteins extract of the lacrimal sac was subjected to chromatography on lectin-affigel columns. Eluted samples from each of the lectin coupled-affigels were analyzed by 10% SDS-PAGE under reducing conditions and the protein bands were visualized using Coomassie blue stain. The protein gel bands were further subjected to mass spectrometry for glycoprotein analysis. Results: Mass spectrometry identified several glycoproteins from the lacrimal sac extracts, with known roles in defense mechanisms. The number of such glycoproteins identified were 9 each from Con A and DLL-I affinity eluted gel bands and 8 and 14 from MCL and WGA affinity eluted gel bands, respectively. Interestingly, PIP was detected in significant proportions in all the eluted gel bands with WGA showing the highest expression. Conclusions: This study is the first step towards the lacrimal sac glycoprotein profiling. PIP could be a major lead for further work on the etiopathogenesis of lacrimal drainage obstructions.