Characterization of mucins in human lacrimal sac and nasolacrimal duct.
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PURPOSE: Mucins are polymers that may reduce drag and enhance tear outflow. Mucin expression and distribution in human efferent tear ducts were tested in the physiological state, and potential differences in the expression pattern were investigated in the presence of primary acquired dacryostenosis (PANDO). METHODS: Expression of mucins in human lacrimal sac and nasolacrimal ducts was monitored by reverse transcription-polymerase chain reaction analysis. The presence and distribution of MUC1, -2, -4, -5AC, -5B, -6, and -7 in epithelia of the efferent tear duct passage are assessed with antisera to mucin peptide cores. Twenty normal tissues from cadavers and surgical specimens from 20 patients with PANDO were tested. RESULTS: mRNAs for all mucins investigated were detected in healthy human lacrimal sacs and nasolacrimal ducts. MUC6 mRNA was detected in only about half of the investigated samples. A reduced level of MUC2, -5AC, and -5B mRNAs was observed in PANDO. Immunohistochemistry revealed MUC2 in goblet cells and single epithelial cells. Both MUC5AC and -5B were detected in goblet cells forming intraepithelial mucous glands. MUC7 was present only in columnar epithelial cells of the efferent tear duct system. No immunoreactivity was observed with antibodies against MUC1, -4, and -6 peptide cores. CONCLUSIONS: Human efferent tear ducts express and produce a broad spectrum of mucins that is partly comparable with that in the conjunctiva and the salivary glands. The mucin diversity of the efferent tear ducts could enhance tear transport and antimicrobial defense. Reduced levels of mucin mRNA in a nonfunctioning though patent segment of the lacrimal passage, which is associated with epiphora, suggests that mucins ease tear flow through the efferent tear ducts. (+info)
Blockage of the lacrimal drainage apparatus as a side effect of docetaxel therapy.
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BACKGROUND: The current study was conducted to report the severity and management of canalicular and nasolacrimal duct stenosis as a side effect of docetaxel therapy and to report the outcomes of surgical intervention for this condition. METHODS: The records of 148 patients with epiphora associated with docetaxel therapy who were evaluated at the Ophthalmology Service at The University of Texas M. D. Anderson Cancer Center were reviewed. The frequency of docetaxel administration, the dose intensity, the cumulative dose of docetaxel, and any concomitant chemotherapeutic agents were recorded. Each patient underwent an ophthalmologic examination and in-office probing and irrigation. The patients either were treated with topical steroids or offered a surgical procedure for canalicular stenosis- (silicone intubation, dacryocystorhinostomy [DCR] with the placement of silicone tubes, or DCR with the placement of Pyrex glass tubes), depending on the severity of the canalicular stenosis. RESULTS: Docetaxel was given weekly in 71 patients, every 2 weeks in 5 patients, and every 3 weeks in 72 patients. Thirty patients (59 eyes) who received weekly docetaxel underwent surgery to correct epiphora. Twenty-three patients (39 eyes) were treated with temporary silicone tube placement, 9 patients (13 eyes) were treated with DCR with temporary silicone tube placement, and 4 patients (7 eyes) were treated with DCR with permanent Pyrex glass tube placement. Twenty-nine of the 30 patients who underwent surgery reported improvement or total resolution of epiphora after the procedure. Ten additional patients (20 eyes) who received weekly docetaxel had complete closure of their canaliculi but elected not to undergo surgery. Of special note were two patients who received weekly docetaxel in the neoadjuvant setting and developed complete closure of the canaliculi. Of the patients who received docetaxel every 2 or 3 weeks, only 3 required a surgical intervention to correct epiphora; none required Pyrex glass tube placement. CONCLUSIONS: Canalicular and nasolacrimal duct obstruction is a common side effect of weekly docetaxel therapy and can occur even when this drug is used in the neoadjuvant setting. The results of the current study indicate that early temporary silicone intubation in symptomatic patients receiving weekly docetaxel can prevent further closure of the lacrimal drainage apparatus and obviate more involved surgical interventions and permanent Pyrex glass tube placement. Cancer 2003;98:504-7. (+info)
Late and very late initial probing for congenital nasolacrimal duct obstruction: what is the cause of failure?
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AIMS: To find the cure rate of late (second year of age) and very late (3-5 years of age) initial probing for congenital nasolacrimal duct obstruction (CNLDO) and to identify the factors contributing to the failure rate of the probing in older children. METHODS: In a prospective interventional case series study, 169 eyes of 125 consecutive patients (1-5 years old) with CNLDO underwent probing under general anaesthesia. Cure was defined as absence of tearing and discharge in the affected eye. RESULTS: 138 eyes of 101 patients aged 13-60 months (mean 23.4 (SD 10.2)) were included. Of 15 eyes (10.8%) with complex CNLDO, 80% presented after 24 months of age (p<0.0001). The cure rate was 89% in patients 13-24 months of age and 72% after the age of 24 months (p = 0.01). It was 90.2% in the membranous and 33.3% in the complex CNLDO in both late and very late probing (p<0.0001). There was a high correlation (r = 0.97) and no significant difference between the cure rate at 1 week and final follow up. CONCLUSION: Accumulation of the complex CNLDO is the main risk factor for failure of probing in the older children. The outcome of the nasolacrimal duct probing at 1 week follow up is highly indicative of the final outcome. (+info)
Cell-specific expression of CYP2A5 in the mouse respiratory tract: effects of olfactory toxicants.
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We performed a detailed analysis of mouse cytochrome P450 2A5 (CYP2A5) expression by in situ hybridization (ISH) and immunohistochemistry (IHC) in the respiratory tissues of mice. The CYP2A5 mRNA and the corresponding protein co-localized at most sites and were predominantly detected in the olfactory region, with an expression in sustentacular cells, Bowman's gland, and duct cells. In the respiratory and transitional epithelium there was no or only weak expression. The nasolacrimal duct and the excretory ducts of nasal and salivary glands displayed expression, whereas no expression occurred in the acini. There was decreasing expression along the epithelial linings of the trachea and lower respiratory tract, whereas no expression occurred in the alveoli. The hepatic CYP2A5 inducers pyrazole and phenobarbital neither changed the CYP2A5 expression pattern nor damaged the olfactory mucosa. In contrast, the olfactory toxicants dichlobenil and methimazole induced characteristic changes. The damaged Bowman's glands displayed no expression, whereas the damaged epithelium expressed the enzyme. The CYP2A5 expression pattern is in accordance with previously reported localization of protein and DNA adducts and the toxicity of some CYP2A5 substrates. This suggests that CYP2A5 is an important determinant for the susceptibility of the nasal and respiratory epithelia to protoxicants and procarcinogens. (+info)
The cavernous body of the human efferent tear ducts contributes to regulation of tear outflow.
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PURPOSE: To test the hypothesis that the surrounding vascular plexus of the lacrimal sac and the nasolacrimal duct contributes to the regulation of tear outflow. METHODS: Experiments in 30 probands aged between 15 and 37 years were performed in both nasolacrimal systems of each subject by observing with an endoscope the transit time of an applied tear drop containing fluorescein dye until its entry into the inferior meatus of the nose. Four different experiments were performed to determine the median transit time under normal conditions and the influence on transit time of a decongestant drug, a foreign body on the ocular surface, and a decongestant drug applied together with a foreign body on the ocular surface. Comparisons were made between the right and left nasolacrimal system, in males and females, eyeglass wearers and non-eyeglass wearers, and the different experiments and the results statistically analyzed. RESULTS: The tear transit time was independent of side (right or left), gender, or eyeglass wear. It showed great individual variability. Application of a decongestant drug or placement of a foreign body on the ocular surface both prolonged the dye transit time significantly. Application of a decongestant drug simultaneously with placement of a foreign body shortened the dye transit time significantly compared with the effect of the decongestant drug alone but revealed no significant difference compared with application of a foreign body alone. CONCLUSIONS: The cavernous body of the lacrimal sac and nasolacrimal duct plays an important role in the physiology of tear outflow regulation. It is subject to autonomic control and is integrated into a complex neuronal reflex feedback mechanism starting with the dense innervation of the cornea. Moreover, its function can be pharmacologically influenced. (+info)
Neurilemmoma of the anterior ethmoidal nerve encroaching upon the nasolacrimal duct.
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The clinical, light microscopic, ultrastructural, and immunohistologic findings of a neurilemmoma encroaching upon the nasolacrimal duct are presented. This is the first reported case of this rare tumour of the nasolacrimal duct where the diagnosis has been confirmed by electron microscopy and immunohistochemical techniques. (+info)
Congenital dacryocystocele: prenatal 2- and 3-dimensional sonographic findings.
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OBJECTIVE: The purpose of this series is to present our experience with cases of dacryocystocele diagnosed prenatally. The role of prenatal 3-dimensional sonography, as an adjunct to 2-dimensional sonography, in the prenatal assessment of these cases is emphasized. METHODS: A retrospective review of cases was conducted. Information was obtained by reviewing the sonographic reports and medical records. Outcomes were obtained from the referring obstetricians or directly from the parents. RESULTS: Ten fetuses had the diagnosis of a congenital dacryocystocele at a median gestational age of 30.1 weeks (range, 27-33 weeks). In 6 cases, the cystic lesion was unilateral, and in 4 it was bilateral, with a mean largest diameter at the time of diagnosis of 7.5 mm (range, 4-11 mm). There were no other associated findings. Three-dimensional sonography, carried out in 3 cases, clearly depicted the anomaly, the degree of intranasal extension, and swelling below the medial canthal area. Spontaneous resolution was documented prenatally in 5 fetuses, and 1 additional case resolved between the last prenatal scan and the delivery. There were no reported long-term complications associated with this finding, although 1 infant required probing at 2 months of age to resolve the dacryocystocele. CONCLUSIONS: Prenatal diagnosis of dacryocystocele is straightforward. A considerable number of lesions are bilateral, and many resolve in utero spontaneously or neonatally after minimal intervention. For those not resolving by the time of the delivery, ophthalmologic or rhinologic consultation is warranted because of potential complications. Three-dimensional sonography may provide a noninvasive method for evaluating these cystic masses and may contribute to the avoidance of additional diagnostic techniques in the neonatal period. (+info)
Clinical outcome of endonasal KTP laser assisted dacryocystorhinostomy.
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BACKGROUND: To evaluate the clinical outcome of primary endonasal laser assisted dacryocystorhinostomy (ENL-DCR) using the potassium-titanyl-phosphate laser. METHODS: We retrospectively reviewed all primary ENL-DCRs performed within a period of twelve months by the same combined Ophthalmology and Otorhinolaringology team in Freeman Hospital, Newcastle upon Tyne, UK. The main outcome measure for success was resolution or significant improvement of epiphora. Details of surgery, intraoperative and postoperative complications, as well as pathology associated with failure were also studied. Patients were followed up for at least 12 months. RESULTS: A total of 41 consecutive ENL-DCRs on 29 patients (22 females, 7 males, mean age 75 years) were analysed. All patients had bicanalicular silicone intubation for at least 4 months. The success rate at 12 months postoperatively was 78.1%. Pathology associated with failure included: intranasal pathology (12.2%), mucocele (7.3%), and systemic sarcoidosis (2.4%). No significant intra-operative complications were recorded. CONCLUSION: The ENL-DCR with potassium-titanyl-phosphate laser can be considered as a safe and efficient primary procedure for the treatment of nasolacrimal duct obstruction. (+info)