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Molecular Vision 2021Rosacea is a chronic inflammatory disease that affects the face skin. It is clinically classified into the following four subgroups depending on its location and... (Review)
Review
Rosacea is a chronic inflammatory disease that affects the face skin. It is clinically classified into the following four subgroups depending on its location and severity: erythematotelangiectatic, papulopustular, phymatous, and ocular. Rosacea is a multifactorial disease triggered by favoring factors, the pathogenesis of which remains imperfectly understood. Recognized mechanisms include the innate immune system, with the implication of Toll-like receptors (TLRs) and cathelicidins; neurovascular deregulation involving vascular endothelial growth factor (VEGF), transient receptor potential (TRP) ion channels, and neuropeptides; and dysfunction of skin sebaceous glands and ocular meibomian glands. Microorganisms, genetic predisposition, corticosteroid treatment, and ultraviolet B (UVB) radiation are favoring factors. In this paper, we review the common and specific molecular mechanisms involved in the pathogenesis of cutaneous and ocular rosacea and discuss laboratory and clinical studies, as well as experimental models.
Topics: Animals; Disease Models, Animal; Eye Diseases; Humans; Models, Biological; Rosacea; Skin Diseases
PubMed: 34035646
DOI: No ID Found -
Annals of Medicine Dec 2023Dry eye disease (DED) is a multifactorial disorder characterized by loss of tear film homeostasis with an estimated worldwide prevalence of 5% to 50%. In DED,... (Review)
Review
Dry eye disease (DED) is a multifactorial disorder characterized by loss of tear film homeostasis with an estimated worldwide prevalence of 5% to 50%. In DED, dysfunction of the ocular structures that create and regulate the tear film components-including the lacrimal glands, meibomian glands, cornea, and conjunctiva-causes a qualitative and/or quantitative tear deficiency with resultant tear film instability and hyperosmolarity. This initiates a vicious cycle of ocular surface inflammation and damage that may ultimately impair the quality of life and vision of affected patients. Many factors can contribute to the development of DED, including ocular and systemic diseases, topical and systemic medications, and environmental conditions. Because DED is a chronic disorder, treatment is most often long term and may utilize both pharmacologic and nonpharmacologic interventions to address all etiologic components. The long-term management of DED can be challenging and most often should involve eye care specialist referral. However, primary care clinicians (PCCs) are often the first points of contact for patients with DED and importantly provide initial diagnosis and preliminary patient education about the disease process. Consideration of DED is also vital for the practice of various specialties due to the large number of comorbidities and medications that can contribute to DED pathogenesis and progression. Therefore, it is important that PCCs and clinical specialists be aware of the etiology of DED and its available therapeutic options. This manuscript provides an overview of DED pathophysiology and treatment and discusses specific considerations regarding DED management for PCCs and clinical specialists.Key messagesSuccessful management of dry eye disease often requires the use of various pharmacologic and/or nonpharmacologic therapies, as well as environmental and lifestyle modifications, to mitigate the underlying etiologies and restore tear film homeostasis.Primary care clinicians play an essential role in dry eye disease management by establishing a diagnosis, educating patients about the disorder, and providing referrals to eye care specialists for initiation of specialized treatment and long-term follow-up.Primary care clinicians and clinical specialists should consider prescribing medications with fewer ocular surface effects whenever possible in patients at risk for or with existing dry eye disease.
Topics: Humans; Quality of Life; Dry Eye Syndromes; Conjunctiva; Tears; Primary Health Care
PubMed: 36576348
DOI: 10.1080/07853890.2022.2157477 -
The Ocular Surface Oct 2020To review the published literature related to application of intense pulsed light (IPL) for treating meibomian gland dysfunction (MGD). (Review)
Review
PURPOSE
To review the published literature related to application of intense pulsed light (IPL) for treating meibomian gland dysfunction (MGD).
METHODS
The literature search included the PubMed database and used the keywords "Intense Pulsed Light and Meibomian Gland Dysfunction".
RESULTS
IPL is a new instrumental treatment modality for MGD. This treatment modality was originally developed for use in dermatology and was later adopted in ophthalmology for treating MGD. IPL therapy for MGD can improve tear film stability, meibomian gland functionality, as well as subjective feeling of ocular dryness. However, in the reviewed literature, there was great variability in patient selection, evaluation criteria, and treatment protocols and durations.
CONCLUSION
Numerous studies report that IPL is effective for treating MGD and a safe procedure. There is great potential for further improvements to the procedure, as large comparative studies employing different treatment modalities are lacking.
Topics: Humans; Intense Pulsed Light Therapy; Meibomian Gland Dysfunction; Meibomian Glands; Ophthalmology; Tears
PubMed: 32629039
DOI: 10.1016/j.jtos.2020.06.002 -
The World Journal of Men's Health Jul 20205α-dihydrotestosterone (5α-DHT) is the most potent natural androgen. 5α-DHT elicits a multitude of physiological actions, in a host of tissues, including prostate,... (Review)
Review
5α-dihydrotestosterone (5α-DHT) is the most potent natural androgen. 5α-DHT elicits a multitude of physiological actions, in a host of tissues, including prostate, seminal vesicles, hair follicles, skin, kidney, and lacrimal and meibomian glands. However, the physiological role of 5α-DHT in human physiology, remains questionable and, at best, poorly appreciated. Recent emerging literature supports a role for 5α-DHT in the physiological function of liver, pancreatic β-cell function and survival, ocular function and prevention of dry eye disease and kidney physiological function. Thus, inhibition of 5α-reductases with finasteride or dutasteride to reduce 5α-DHT biosynthesis in the course of treatment of benign prostatic hyperplasia (BPH) or male pattern hair loss, known as androgenetic alopecia (AGA) my induces a novel form of tissue specific androgen deficiency and contributes to a host of pathophysiological conditions, that are yet to be fully recognized. Here, we advance the concept that blockade of 5α-reductases by finasteride or dutasteride in a mechanism-based, irreversible, inhabitation of 5α-DHT biosynthesis results in a novel state of androgen deficiency, independent of circulating testosterone levels. Finasteride and dutasteride are frequently prescribed for long-term treatment of lower urinary tract symptoms in men with BPH and in men with AGA. This treatment may result in development of non-alcoholic fatty liver diseases (NAFLD), insulin resistance (IR), type 2 diabetes (T2DM), dry eye disease, potential kidney dysfunction, among other metabolic dysfunctions. We suggest that long-term use of finasteride and dutasteride may be associated with health risks including NAFLD, IR, T2DM, dry eye disease and potential kidney disease.
PubMed: 32202088
DOI: 10.5534/wjmh.200012 -
Investigative Ophthalmology & Visual... Jan 2022Patients diagnosed with diabetes are inclined to have abnormalities on stability of tear film and disorder of meibomian gland (MG). This study aims to explore the...
PURPOSE
Patients diagnosed with diabetes are inclined to have abnormalities on stability of tear film and disorder of meibomian gland (MG). This study aims to explore the pathological change of MG induced by diabetes in a rat model.
METHODS
Sprague-Dawley (SD) rats were intraperitoneally injected with streptozotocin (STZ) to establish a diabetic animal model. Lipid accumulation in MG was detected by Oil Red O staining and LipidTox staining. Cell proliferation status was determined by Ki67 and P63 immunostaining, whereas cell apoptosis was confirmed by TUNEL assay. Gene expression of inflammatory cytokines and adhesion molecules IL-1α, IL-1β, ELAM1, ICAM1, and VCAM1 were detected by RT-PCR. Activation of ERK, NF-κB, and AMPK signaling pathways was determined by Western Blot analysis. Oxidative stress-related factors NOX4, 4HNE, Nrf2, HO-1, and SOD2 were detected by immunostaining or Western Blot analysis. Tom20 and Tim23 immunostaining and transmission electron microscopy were performed to evaluate the mitochondria functional and structure change.
RESULTS
Four months after STZ injection, there was acini dropout in MG of diabetic rats. Evident infiltration of inflammatory cells, increased expression of inflammatory factors, and adhesion molecules, as well as activated ERK and NF-κB signaling pathways were identified. Oxidative stress of MG was evident in 4-month diabetic rats. Phospho-AMPK was downregulated in MG of 2-month diabetic rats and more prominent in 4-month rats. After metformin treatment, phospho-AMPK was upregulated and the morphology of MG was well maintained. Moreover, inflammation and oxidative stress of MG were alleviated after metformin intervention.
CONCLUSIONS
Long-term diabetes may lead to Meibomian gland dysfunction (MGD). AMPK may be a therapeutic target of MGD induced by diabetes.
Topics: Animals; Blood Glucose; Cytokines; Disease Models, Animal; Hyperglycemia; Male; Meibomian Gland Dysfunction; Meibomian Glands; Oxidative Stress; Rats; Rats, Sprague-Dawley; Signal Transduction
PubMed: 35072689
DOI: 10.1167/iovs.63.1.30 -
Clinical & Experimental Optometry Apr 2021The multifactorial pathogenesis and interrelationship of blepharitis, meibomian gland dysfunction and dry eye disease poses challenges to any therapeutic approach.... (Review)
Review
The multifactorial pathogenesis and interrelationship of blepharitis, meibomian gland dysfunction and dry eye disease poses challenges to any therapeutic approach. Current treatments are mostly palliative, with success limited by perceived inefficacy and poor patient compliance. Castor oil, a natural derivative of the Ricinus communis plant, is widely used as an emollient in cosmetics and personal care products, drug delivery systems and wound dressings. Castor oil is deemed safe and tolerable, with strong anti-microbial, anti-inflammatory, anti-nociceptive, analgesic, antioxidant, wound healing and vaso-constrictive properties. Its main constituent, ricinoleic acid, has a bipolar molecular structure that promotes the formation of esters, amides and polymers. These can supplement deficient physiological tear film lipids, enabling enhanced lipid spreading characteristics and reducing aqueous tear evaporation. Studies reveal that castor oil applied topically to the ocular surface has a prolonged residence time, facilitating increased tear film lipid layer thickness, stability, improved ocular surface staining and symptoms. This review summarises the properties, current uses of, and therapeutic potential of castor oil in managing ocular surface disease. The biochemical, medicinal actions of castor oil are explored from the perspective of ocular surface pathology, and include microbial and demodectic over-colonisation, inflammatory and oxidative processes, as well as clinical signs and symptoms of dryness and discomfort.
Topics: Blepharitis; Castor Oil; Dry Eye Syndromes; Humans; Meibomian Gland Dysfunction; Meibomian Glands; Tears
PubMed: 33037703
DOI: 10.1111/cxo.13148 -
Survey of Ophthalmology 2022The human tear film is at the interface between the ocular surface and the external environment. Although investigation has been hindered by its small volume,... (Review)
Review
The human tear film is at the interface between the ocular surface and the external environment. Although investigation has been hindered by its small volume, improvements in preanalytical and analytical methods have allowed the omics approach to represent an innovative biomarker search strategy. There is still a significant lack of standardization, representing a barrier for performing between-studies comparisons and transferring experimental findings into clinical use and trials. We summarize the preanalytical and analytical procedures, describe the biomarkers that can be found using the metabo-lipidomics approach, and provide our expert opinion for omics investigations in human tears. For this systematic review of 38 studies, we searched PubMed by combining Boolean operators with the following keywords: tear, metabolomic, lipidomic, -omics. The human tear metabo-lipidome has been well-characterized in normal individuals using high-resolution liquid chromatography coupled with mass spectrometry. Lipid and metabolite profiles were influenced by ocular (e.g., dry eye disorders; Meibomian gland dysfunction; contact lens wear; glaucoma; keratoconus; pterygium) and systemic conditions (e.g., multiple sclerosis). Investigating the tear metabo-lipidome could improve our understanding of the pathogenesis of both ocular and systemic diseases, but also provide diagnostic as well as prognostic biomarkers.
Topics: Biomarkers; Dry Eye Syndromes; Humans; Lipidomics; Meibomian Glands; Metabolomics; Tears
PubMed: 35093405
DOI: 10.1016/j.survophthal.2022.01.010 -
Clinical & Experimental Optometry Jul 2021Dry eye disease is one of the most common, chief-complaints presenting in clinical practice, with a prevalence of up to 50%. Evaporative dry eye, as a result of...
Dry eye disease is one of the most common, chief-complaints presenting in clinical practice, with a prevalence of up to 50%. Evaporative dry eye, as a result of meibomian gland dysfunction, is thought to be the biggest component factor. Treatments for meibomian gland dysfunction aim to restore tear film homoeostasis and include warm compress therapy, eyelid hygiene, in-office meibomian gland expression and lipid-containing, artificial tears. A recent introduction to the in-office treatments available for meibomian gland dysfunction has been low-level light therapy, also known as photobiomodulation. The technique involves applying red, or near infra-red, radiation using low-power light sources and is suggested to promote tissue repair, decrease inflammation, and relieve pain. This work aims to review the available literature on the efficacy and safety of photobiomodulation in meibomian gland dysfunction and dry eye disease, as well as what is currently known about its mechanism of action.
Topics: Dry Eye Syndromes; Eyelid Diseases; Humans; Low-Level Light Therapy; Meibomian Gland Dysfunction; Meibomian Glands; Tears
PubMed: 33689636
DOI: 10.1080/08164622.2021.1878866 -
Indian Journal of Ophthalmology Apr 2023Dry eye disease (DED) is a commonly occurring, multifactorial disease characterized by reduced tear film stability and hyperosmolarity at the ocular surface, leading to... (Review)
Review
Dry eye disease (DED) is a commonly occurring, multifactorial disease characterized by reduced tear film stability and hyperosmolarity at the ocular surface, leading to discomfort and visual compromise. DED is driven by chronic inflammation and its pathogenesis involves multiple ocular surface structures such as the cornea, conjunctiva, lacrimal glands, and meibomian glands. The tear film secretion and its composition are regulated by the ocular surface in orchestration with the environment and bodily cues. Thus, any dysregulation in ocular surface homeostasis causes an increase in tear break-up time (TBUT), osmolarity changes, and reduction in tear film volume, all of which are indicators of DED. Tear film abnormalities are perpetuated by underlying inflammatory signaling and secretion of inflammatory factors, leading to the recruitment of immune cells and clinical pathology. Tear-soluble factors such as cytokines and chemokines are the best surrogate markers of disease severity and can also drive the altered profile of ocular surface cells contributing to the disease. Soluble factors can thus help in disease classification and planning treatment strategies. Our analysis suggests increased levels of cytokines namely interleukin-1β (IL-1β), IL-2, IL-4, IL-6, IL-9, IL-12, IL-17A, interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α); chemokines (CCL2, CCL3, CCL4, CXCL8); MMP-9, FGF, VEGF-A; soluble receptors (sICAM-1, sTNFR1), neurotrophic factors (NGF, substance P, serotonin) and IL1RA and reduced levels of IL-7, IL-17F, CXCL1, CXCL10, EGF and lactoferrin in DED. Due to the non-invasive sample collection and ease of quantitively measuring soluble factors, tears are one of the best-studied biological samples to molecularly stratify DED patients and monitor their response to therapy. In this review, we evaluate and summarize the soluble factors profiles in DED patients from the studies conducted over the past decade and across various patient groups and etiologies. The use of biomarker testing in clinical settings will aid in the advancement of personalized medicine and represents the next step in managing DED.
Topics: Humans; Dry Eye Syndromes; Tears; Cytokines; Chemokines; Biomarkers; Lacrimal Apparatus
PubMed: 37026250
DOI: 10.4103/IJO.IJO_2981_22