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The Ocular Surface Oct 2020Tear secretion is a complex process with the involvement of the main and accessory lacrimal glands, corneal and conjunctival epithelial cells and the Meibomian glands.... (Review)
Review
Tear secretion is a complex process with the involvement of the main and accessory lacrimal glands, corneal and conjunctival epithelial cells and the Meibomian glands. The lacrimal gland is the main source of fluid, electrolytes and proteins in tear fluid. Deficient ion and water secretion results in aqueous deficient dry eye with serious consequences on the integrity of the ocular surface. Functions of acinar cells are widely studied, whereas less information is available about the duct system of the lacrimal gland. Secretory mechanisms of duct epithelium may play an important role in tear production, but only limited studies have tried to elucidate the role of the duct system in tear secretion. Significant progress has been made in the past few years, resulting in new insight into lacrimal gland duct function. New experimental techniques were introduced, which contributed to the exploration of the role of lacrimal gland ducts in more detail. Therefore, the aim of this review is to summarize our present knowledge about the role of ducts in lacrimal gland function and tear secretion, which appears to be the first review with a focus on this topic. Short outline of pancreatic and salivary gland duct functions is also given for the purposes of comparison.
Topics: Cornea; Dry Eye Syndromes; Epithelium; Humans; Lacrimal Apparatus; Tears
PubMed: 32707335
DOI: 10.1016/j.jtos.2020.07.002 -
Aging Aug 2023
Topics: Lacrimal Apparatus; Aging
PubMed: 37579224
DOI: 10.18632/aging.204651 -
Arquivos Brasileiros de Oftalmologia 2022This study aimed to compare the changes in the lacrimal functional unit in the following two models of neurogenic dry eye syndrome: sensory denervation of the cornea...
PURPOSE
This study aimed to compare the changes in the lacrimal functional unit in the following two models of neurogenic dry eye syndrome: sensory denervation of the cornea versus autonomic denervation of the lacrimal gland.
METHODS
The neural network supports the lacrimal functional unit. It can be divided into afferent (sensory) and efferent (autonomic) pathways and is affected by severe diseases that compromise the lacrimal functional unit. Male Wistar, 8-week-old rats were divided into the following three groups: 1) control naïve (n=16 animals); 2) autonomic denervation: where rats were subjected to right lacrimal gland nerve ablation and evaluated after 1 and 2 months (1M and 2M) after the procedure (n=7 animals per subgroup, autonomic denervation 1M and autonomic denervation 2M, respectively); 3) sensory denervation induced by 0.2% benzalkonium chloride eye drops, twice a day for 7 days in the right eye (n=10 animals). The corneal sensitivity was measured using the eye wipe test with capsaicin (10 µM). The quantitative real-time PCR was performed to compare the mRNA expressions of proinflammatory cytokines, such as Il-1β, Il-6, Tnf, Mmp9, in the cornea, trigeminal ganglion, and lacrimal gland. In addition, the mRNA of the promitotic factors in the lacrimal gland, such as Bmp7, Runx1, Runx3, Fgf10, and Smad1, was compared.
RESULTS
Sensory denervation induced corneal hyperalgesia (p=0.001). Sensory denervation and autonomic denervation increased the mRNA of proinflammatory cytokines in the cornea and lacrimal gland (p<0.05), but only sensory denervation increased the mRNA levels of Il-1β and Tnf in the trigeminal ganglion (p<0.05) compared with the control naïve.
CONCLUSIONS
Autonomic denervation and sensory denervation models can have common features, such as inflammation of different parts of the lacrimal functional unit. However, hyperesthesia and inflammatory markers in the trigeminal ganglion because of sensory denervation and the expression of regenerative mediators in the lacrimal gland owing to autonomic denervation are the distinguishing features of these diseases that can be explored in future studies assessing dry eye syndrome secondary to neural damage of the lacrimal functional unit.
Topics: Animals; Cornea; Denervation; Dry Eye Syndromes; Lacrimal Apparatus; Male; Rats; Rats, Wistar; Tears
PubMed: 34586229
DOI: 10.5935/0004-2749.20220008 -
BMC Ophthalmology Aug 2023Thyroid eye disease is an extrathyroidal manifestation of Graves' disease and is associated with dry eye disease. This is the first systematic review and meta-analysis... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Thyroid eye disease is an extrathyroidal manifestation of Graves' disease and is associated with dry eye disease. This is the first systematic review and meta-analysis to evaluate the role of magnetic resonance imaging lacrimal gland parameters in thyroid eye disease diagnosis, activity grading, and therapeutic responses prediction.
METHODS
Up to 23 August, 2022, 504 studies from PubMed and Cochrane Library were analyzed. After removing duplicates and imposing selection criteria, nine eligible studies were included. Risk of bias assessment was done. Meta-analyses were performed using random-effect model if heterogeneity was significant. Otherwise, fixed-effect model was used. Main outcome measures include seven structural magnetic resonance imaging parameters (lacrimal gland herniation, maximum axial area, maximum coronal area, maximum axial length, maximum coronal length, maximum axial width, maximum coronal width), and three functional magnetic resonance imaging parameters (diffusion tensor imaging-fractional anisotropy, diffusion tensor imaging-apparent diffusion coefficient or mean diffusivity, diffusion-weighted imaging-apparent diffusion coefficient).
RESULTS
Thyroid eye disease showed larger maximum axial area, maximum coronal area, maximum axial length, maximum axial width, maximum coronal width, diffusion tensor imaging-apparent diffusion coefficient/ mean diffusivity, and lower diffusion tensor imaging-fractional anisotropy than controls. Active thyroid eye disease showed larger lacrimal gland herniation, maximum coronal area, diffusion-weighted imaging-apparent diffusion coefficient than inactive. Lacrimal gland dimensional (maximum axial area, maximum coronal area, maximum axial length, maximum axial width, maximum coronal width) and functional parameters (diffusion tensor imaging-apparent diffusion coefficient, diffusion tensor imaging-apparent diffusion coefficient) could be used for diagnosing thyroid eye disease; lacrimal gland herniation, maximum coronal area, and diffusion-weighted imaging-apparent diffusion coefficient for differentiating active from inactive thyroid eye disease; diffusion tensor imaging parameters (diffusion tensor imaging-fractional anisotropy, diffusion tensor imaging-mean diffusivity) and lacrimal gland herniation for helping grading and therapeutic responses prediction respectively.
CONCLUSIONS
Magnetic resonance imaging lacrimal gland parameters can detect active thyroid eye disease and differentiate thyroid eye disease from controls. Maximum coronal area is the most effective indicator for thyroid eye disease diagnosis and activity grading. There are inconclusive results showing whether structural or functional lacrimal gland parameters have diagnostic superiority. Future studies are warranted to determine the use of magnetic resonance imaging lacrimal gland parameters in thyroid eye disease.
Topics: Humans; Graves Ophthalmopathy; Lacrimal Apparatus; Diffusion Tensor Imaging; Magnetic Resonance Imaging; Outcome Assessment, Health Care
PubMed: 37550660
DOI: 10.1186/s12886-023-03008-x -
Investigative Ophthalmology & Visual... Aug 2022As part of the lacrimal apparatus, the lacrimal gland participates in the maintenance of a healthy eye surface by producing the aqueous part of the tear film. Alacrimia... (Review)
Review
As part of the lacrimal apparatus, the lacrimal gland participates in the maintenance of a healthy eye surface by producing the aqueous part of the tear film. Alacrimia and hypolacrimia, which are relatively rare during childhood or young adulthood, have their origin in a number of mechanisms which include agenesia, aplasia, hypoplasia, or incorrect maturation of the gland. Moreover, impaired innervation of the gland and/or the cornea and alterations of protein secretion pathways can lead to a defective tear film. In most conditions leading to alacrimia or hypolacrimia, however, the altered tear film is only one of numerous defects that arise and therefore is commonly disregarded. Here, we have systematically reviewed all of those genetic conditions or congenital disorders that have alacrimia or hypolacrimia as a feature. Where it is known, we describe the mechanism of the defect in question. It has been possible to clearly establish the physiopathology of only a minority of these conditions. As hypolacrimia and alacrimia are rare features, this review could be used as a tool in clinical genetics to perform a quick diagnosis, necessary for appropriate care and counseling.
Topics: Adult; Cornea; Dry Eye Syndromes; Humans; Lacrimal Apparatus; Tears; Young Adult
PubMed: 35925585
DOI: 10.1167/iovs.63.9.3 -
Der Ophthalmologe : Zeitschrift Der... Jun 2021This article presents the case of a strictly unilateral dry eye syndrome in a male patient. Based on a stepwise diagnostic procedure the spectrum of possible causes...
This article presents the case of a strictly unilateral dry eye syndrome in a male patient. Based on a stepwise diagnostic procedure the spectrum of possible causes could be gradually limited, whereby the magnetic resonance imaging of the lacrimal gland in particular provided important diagnostic information. Ultimately, in the synopsis of the findings and combined with the medical history of the patient, a traumatic atrophy of the lacrimal gland could be determined as the triggering factor.
Topics: Atrophy; Dry Eye Syndromes; Humans; Lacrimal Apparatus; Male
PubMed: 32647926
DOI: 10.1007/s00347-020-01168-5 -
Journal of Cancer Research and Clinical... Jan 2024The incidence of lacrimal gland adenocarcinoma is low. This study was designed to analyze the clinical and prognostic characteristics of lacrimal gland adenocarcinoma. (Review)
Review
PURPOSE
The incidence of lacrimal gland adenocarcinoma is low. This study was designed to analyze the clinical and prognostic characteristics of lacrimal gland adenocarcinoma.
METHODS
This was a clinical study and literature review; 25 patients diagnosed with lacrimal gland adenocarcinoma by histopathology were enrolled and their medical history data were collected.
RESULTS
The incidence of bone destruction and surrounding tissue invasion was 52% and 44%, respectively. The incidence of distant metastasis of lacrimal gland adenocarcinoma was about 50%. The 5-year overall survival rate of death or metastasis was 33.5%. Age, sex, laterality, tumor size, pathology type, bone destruction, nerve or perineural invasion, invasion of peripheral tissue, T stage, AR, Her-2 and treatment had no significant correlation with lacrimal adenocarcinoma's prognosis (P > 0.05), while the higher expression of Ki-67 may have higher risk of death or metastasis (P = 0.020).
CONCLUSION
The incidence of bone destruction and distant metastasis of lacrimal adenocarcinoma is high and the imaging examination is necessary to assess the risk of distant metastasis. The 5-year survival rate of death or metastasis is 33.5% and the high expression of Ki-67 predicts poor prognosis of lacrimal adenocarcinoma.
Topics: Humans; Lacrimal Apparatus; Ki-67 Antigen; Oncogenes; Adenocarcinoma
PubMed: 38263473
DOI: 10.1007/s00432-023-05510-7 -
The British Journal of Ophthalmology Nov 2023We report visual outcomes and ocular complications in patients with lacrimal gland carcinoma who had eye-sparing surgery followed by radiotherapy. (Review)
Review
BACKGROUND
We report visual outcomes and ocular complications in patients with lacrimal gland carcinoma who had eye-sparing surgery followed by radiotherapy.
METHODS
This review included consecutive patients with lacrimal gland carcinoma who underwent eye-sparing surgery and adjuvant radiotherapy or concurrent chemoradiation therapy between 2007 and 2018. Clinical data, including details of ophthalmological examinations and radiation treatment were reviewed.
RESULTS
The study included 23 patients, 15 males and 8 females, with median age 51 years. Twenty patients (87%) received intensity-modulated proton therapy; 3 (13%) received intensity-modulated radiotherapy. Nineteen patients (83%) received concurrent chemotherapy. After a median follow-up time of 37 months (range: 8-83), 13 patients (57%) had best-corrected visual acuity 20/40 or better, 3 (13%) had moderate vision loss (between 20/40 and 20/200) and 7 (30%) had severe vision loss (20/200 or worse). The most common ocular complications were dry eye disease (21 patients; 91%), radiation retinopathy (16; 70%) and cataract progression (11; 49%). Tumour crossing the orbital midline (p=0.014) and Hispanic ethnicity (p=0.014) were associated with increased risk of severe vision loss. The risk of radiation retinopathy was significantly different among the three racial groups; Hispanic patients (n=3) had the highest rate of retinopathy (p<0.001). Tumour size, initial T category and total prescribed radiation dose were not significantly associated with severe vision loss.
CONCLUSION
Eye-sparing surgery followed by adjuvant radiotherapy in patients with lacrimal gland carcinoma has a reasonable overall visual prognosis. Patients with tumours crossing the orbital midline and Hispanic patients have a higher risk of severe vision loss.
Topics: Male; Female; Humans; Middle Aged; Radiotherapy, Adjuvant; Lacrimal Apparatus; Eye Neoplasms; Carcinoma; Dry Eye Syndromes; Retinal Diseases; Retrospective Studies
PubMed: 36229179
DOI: 10.1136/bjo-2022-321889 -
Investigative Ophthalmology & Visual... Oct 2018To evaluate spontaneous and evoked ocular sensory responses in rats after denervation of the lacrimal gland, as well as protein changes in tears that may mediate...
PURPOSE
To evaluate spontaneous and evoked ocular sensory responses in rats after denervation of the lacrimal gland, as well as protein changes in tears that may mediate functional changes.
METHODS
Sprague-Dawley rats served as subjects. The left lacrimal gland was partially denervated with saporin toxin conjugated to p75. Unilateral and bilateral eye closures (winks and blinks) and grooming behaviors were measured weekly. Nociceptive responses were evoked by ocular application of menthol; tear production was assessed using the phenol thread test. Relative changes in tear protein abundances were measured using a Tandem Mass Tagging approach.
RESULTS
Denervation of the lacrimal gland reduced eye closure behavior, particularly in the ipsilateral eye, and eye wipe responses to noxious menthol were also reduced. Tear volume did not change, but tear protein composition was altered. Proteins implicated in the structural integrity of epithelial cells and in protective functions were reduced by lacrimal denervation, including keratins, serotransferrin, and beta-defensin. Other proteins that may modulate TRPM8 channels and alter sensory neuronal function were reduced, including arachidonate 15-lipoxygenase B. A low-abundance protein that responds to oxidative stress and injury, proteasome subunit beta type 10, was upregulated in denervated rats.
CONCLUSIONS
Denervation of the lacrimal gland causes long-lasting hypoalgesia, impairs the blink response, and alters tear proteins. Tear proteins were altered without changing tear volume. We speculate that impaired TRPM8 function in corneal sensory nerves may contribute to ocular hypoalgesia, supporting growing evidence that this transduction molecule is important for both nociceptive and spontaneous blinking behaviors.
Topics: Animals; Blinking; Corneal Diseases; Eye Pain; Eye Proteins; Eyelid Diseases; Immunoconjugates; Lacrimal Apparatus; Male; Nerve Block; Nociceptive Pain; Rats; Rats, Sprague-Dawley; Saporins; Tears
PubMed: 30372750
DOI: 10.1167/iovs.18-25267 -
BMJ Case Reports Jul 2020An 80-year-old man referred with repeated episode of dacryocystitis from the left lacrimal drainage system and palpable swelling. For many years, he has being presented... (Review)
Review
An 80-year-old man referred with repeated episode of dacryocystitis from the left lacrimal drainage system and palpable swelling. For many years, he has being presented with epiphora unilaterally with chronic dacryocystitis. Investigations with dye-test revealed subocclusion of the natural passage of the tears, and CT and MRI scans revealed solid mass in the lacrimal sac. The lacrimal sac was opened by endonasal endoscopic approach, the sacral mass was identified and completely removed. The histopathological examination showed lacrimal gland in ectopic position. Patient followed for 18 months with complete recovery of symptoms. In our differential diagnosis, the ectopic lacrimal gland is also identified, when a mass in the lacrimal sac and duct is present. Successful surgical excision required considerable multidisciplinary teamwork between ophtalmologist-ENT (Otolaryngologist) and radiologist. Endonasal endoscopic approach is perfectly safe with direct control and ensures a smooth postoperative recovery.
Topics: Aged, 80 and over; Dacryocystitis; Humans; Lacrimal Apparatus; Male; Nasolacrimal Duct; Treatment Outcome
PubMed: 32699057
DOI: 10.1136/bcr-2020-235187