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The Ocular Surface Apr 2024Meibomian gland dysfunction (MGD) is a chronic abnormality of the Meibomian glands (MGs) that is recognized as the leading cause of evaporative dry eye worldwide.... (Review)
Review
Meibomian gland dysfunction (MGD) is a chronic abnormality of the Meibomian glands (MGs) that is recognized as the leading cause of evaporative dry eye worldwide. Despite its prevalence, however, the pathophysiology of MGD remains elusive, and effective disease management continues to be a challenge. In the past 50 years, different models have been developed to illustrate the pathophysiological nature of MGD and the underlying disease mechanisms. An understanding of these models is crucial if researchers are to select an appropriate model to address specific questions related to MGD and to develop new treatments. Here, we summarize the various models of MGD, discuss their applications and limitations, and provide perspectives for future studies in the field.
Topics: Meibomian Gland Dysfunction; Humans; Meibomian Glands; Animals; Tears; Dry Eye Syndromes; Disease Models, Animal
PubMed: 38490475
DOI: 10.1016/j.jtos.2024.03.003 -
Experimental Eye Research Apr 2024The accumulation of oleic acid (OA) in the meibum from patients with meibomian gland dysfunction (MGD) suggests that it may contribute to meibomian gland (MG) functional...
The accumulation of oleic acid (OA) in the meibum from patients with meibomian gland dysfunction (MGD) suggests that it may contribute to meibomian gland (MG) functional disorder, as it is a potent stimulator of acne-related lipogenesis and inflammation in sebaceous gland. Therefore, we investigate whether OA induces lipogenesis and inflammasome activation in organotypic cultured mouse MG and human meibomian gland epithelial cells (HMGECs). Organotypic cultured mouse MG and HMGECs were exposed to OA or combinations with specific AMPK agonists 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR). Lipogenic status, ductal keratinization, squamous metaplasia, NLRP3/ASC/Caspase-1 inflammasome activation, proinflammatory cytokine IL-1β production, and AMPK pathway phosphorylation in MG were subsequently examined by lipid staining, immunofluorescence staining, immunohistochemical staining, ELISA assay, and Western blot analyses. We found that OA significantly induced lipid accumulation, ductal keratinization, and squamous metaplasia in organotypic cultured MG, as evidenced by increased lipids deposition within acini and duct, upregulated expression of lipogenic proteins (SREBP-1 and HMGCR), and elevation of K10/Sprr1b. Additionally, OA induced NLRP3/ASC/Caspase-1 inflammasome activation, cleavage of Caspase-1, and production of downstream proinflammatory cytokine IL-1β. The findings of lipogenesis and NLRP3-related proinflammatory response in OA-stimulated HMGECs were consistent with those in organotypic cultured MG. OA exposure downregulated phospho-AMPK in two models, while AICAR treatment alleviated lipogenesis by improving AMPK/ACC phosphorylation and SREBP-1/HMGCR expression. Furthermore, AMPK amelioration inhibited activation of the NLRP3/ASC/Caspase-1 axis and secretion of IL-1β, thereby relieving the OA-induced proinflammatory response. These results demonstrated that OA induced lipogenic disorder and NLRP3 inflammasome activation in organotypic cultured mouse MG and HMGECs by suppressing the AMPK signaling pathway, indicating OA may play an etiological role in MGD.
Topics: Humans; Mice; Animals; Inflammasomes; NLR Family, Pyrin Domain-Containing 3 Protein; Sterol Regulatory Element Binding Protein 1; Oleic Acid; Meibomian Glands; AMP-Activated Protein Kinases; Lipogenesis; Epithelial Cells; Caspase 1; Cytokines; Metaplasia; Carcinoma, Squamous Cell; Interleukin-1beta
PubMed: 38453039
DOI: 10.1016/j.exer.2024.109851 -
Journal Francais D'ophtalmologie Apr 2024To evaluate the effect of upper eyelid blepharoplasty surgery on corneal topography, visual field, ocular surface, meibography, corneal biomechanics and dry eye...
PURPOSE
To evaluate the effect of upper eyelid blepharoplasty surgery on corneal topography, visual field, ocular surface, meibography, corneal biomechanics and dry eye parameters.
METHODS
This prospective study included a total 80 eyes of 40 patients. Following a detailed ophthalmological examination, standardized patient satisfaction questions were posed to patients before and after upper eyelid blepharoplasty surgery. Visual field test, non-invasive break up time (NIBUT), meibography, and corneal topography parameters were analyzed and evaluated.
RESULTS
The mean (+) visible areas in the visual field were found to be 46.20±24.96 preoperatively, 56.73±21.98 at the 1st postoperative month and 65.96±18.5 at the 3rd month, which were statistically significant. NIBUT values preoperatively, at 1 month and at 3 months were 11.26±4.48, 11.16±4.5 and 10.14±4.0, respectively, which were statistically significant. Meibomian gland loss rates on meibography preoperatively and postoperatively at 1 and 3 months were found to be 30.24±8.3, 29.36±8.2 and 28.22±7.7 respectively and were statistically significant. With the scoring system after blepharoplasty, patients reported improvement in their symptoms.
CONCLUSION
Upper eyelid blepharoplasty surgery is predicted to increase the quality of vision. It was observed that there was a functional and cosmetic improvement in the complaints of the patients after blepharoplasty. However, blepharoplasty may cause changes in eyelid dynamics and cause dry eye syndrome.
Topics: Humans; Blepharoplasty; Visual Fields; Prospective Studies; Meibomian Glands; Dry Eye Syndromes
PubMed: 38447291
DOI: 10.1016/j.jfo.2024.104135 -
Clinical Ophthalmology (Auckland, N.Z.) 2024To demonstrate that the meibomian gland ductal basement membrane and basal epithelial cell layer are in continuity with and may derive from lid margin orifice-associated...
PURPOSE
To demonstrate that the meibomian gland ductal basement membrane and basal epithelial cell layer are in continuity with and may derive from lid margin orifice-associated rete ridge epithelial/basement membrane structures (OARREBS) and to characterize changes in the distal duct microanatomy after meibomian gland probing (MGP) using in vivo confocal microscopy (IVCM).
PATIENTS AND METHODS
Pre/post-MGP IVCM examinations were performed on upper lids. Thirty-six identical glands from 20 lids of 16 patients (49.24 ±17.11 y/o with 13:3 F:M) were identified, analyzed, and compared to control cases. Statistical analyses were performed using ImageJ software and IBM SPSS version 27. All MGPs were performed within 12 weeks of the initial examination. Post-MGP follow-up exams occurred at 5.03 ±4.48 months.
RESULTS
Post-MGP images showed more superficially organized OARREBS with accelerated and more superficial basement membrane formation, and an average increase of 32.2%, 25.4%, 32.04%, 77.7%, and 81.3% in duct wall epithelial cell layers (DWECL) (p < 0.001, compared to control (CTC) p < 0.001), distal duct wall thickness (DWT) (p < 0.001, CTC p < 0.001), proximal DWT (p < 0.001, CTC p < 0.001), distal lumen area (p < 0.001, CTC p = 0.037), and proximal lumen area (p < 0.001, CTC p = 0.007), respectively. The increase in the distal DWT and lumen area correlated with the months of follow-up (p = 0.004 and p = 0.010, respectively). Immediate post-MGP imaging revealed the probe track confined to the ductal epithelial compartment.
CONCLUSION
MGP appears to stimulate a proliferative epithelial response characterized by an accelerated more superficial formation of ductal basement membrane with increased DWECL as well as DWT and lumen area at two separate duct foci. These findings suggest activation of lid margin meibomian gland precursor cells and confirm that MGP stimulates an epithelial regenerative phenomenon, not a fibrotic one.
PubMed: 38445253
DOI: 10.2147/OPTH.S452549 -
International Ophthalmology Mar 2024Euthyroid Graves' ophthalmology (EGO) refers to the subgroup of thyroid eye disease patients with distinct clinical presentations. This study evaluated the ocular...
PURPOSE
Euthyroid Graves' ophthalmology (EGO) refers to the subgroup of thyroid eye disease patients with distinct clinical presentations. This study evaluated the ocular surface and meibomian gland changes in EGO patients.
METHODS
A cross-sectional study was conducted at The Chinese University of Hong Kong including 34 EGO patients and 34 age-and sex- matched healthy controls. Outcome measures include anterior segment examination, keratographic and meibographic imaging.
RESULTS
Between 34 EGO patients and 34 age and sex-matched healthy controls, EGO was associated with a higher ocular surface disease index (P < 0.01), higher severity of meibomian gland dropout (upper: P < 0.001, lower: P < 0.00001) and higher percentage of partial blinking (P = 0.0036). The worse affected eyes of the EGO patients were associated with corneal staining (P = 0.0019), eyelid telangiectasia (P = 0.0009), eyelid thickening (P = 0.0013), eyelid irregularity (P = 0.0054), meibomian gland plugging (P < 0.00001), expressibility (P < 0.00001), and meibum quality (P < 0.00001). When the two eyes of the same EGO patient were compared, the degree of meibomian gland dropout was higher among the worse affected eyes (upper: P < 0.00001, and lower: P < 0.00001). Tear meniscus height, lipid layer thickness, and noninvasive break-up time were comparable between the two eyes of EGO patients and also between EGO patients and healthy controls. TMH was positively correlated with the degree of exophthalmos (r = 0.383, P < 0.05).
CONCLUSION
EGO patients have more ocular surface complications and meibomian gland dropouts than healthy controls. Almost 60% of them had dry eye symptoms, but aqueous deficiency was not apparent. Further studies are warranted to clarify the mechanism of dry eye in EGO. (249 words).
Topics: Humans; Meibomian Glands; Cross-Sectional Studies; Dry Eye Syndromes; Blinking; Tears
PubMed: 38430354
DOI: 10.1007/s10792-024-02919-y -
The Israel Medical Association Journal... Jan 2024Meibomian gland dysfunction (MGD) causes significant patient morbidity as well as economic burden.
BACKGROUND
Meibomian gland dysfunction (MGD) causes significant patient morbidity as well as economic burden.
OBJECTIVES
To evaluate a novel eyelid warming and a neuro-stimulating device that delivers heat via low-level infrared radiation to the eyelids of patients with MGD.
METHODS
In this prospective interventional study, patients with MGD were recruited at a single medical center. The main outcome measures included changes in tear break-up time (TBUT), Schirmer's test, and Ocular Surface Disease Index (OSDI), overall satisfaction, and corneal signs of dry eye. Patients were instructed to use the device twice daily for 5 minutes on each eye for a total of 14 days. Follow-up assessments were performed after the 2-week treatment.
RESULTS
A total of 10 patients were included; mean age was 67 ± 16 years; six males (60%). Changes in pre- vs. post-treatment TBUT (5.0-6.11), OSDI (28.1-23.9), and Schirmer score (8.67-7.11) were not statistically significant. Over a course of 243 treatments, 131 (54%) demonstrated improvement in symptoms, 40% found no change, and 6% experienced worsening of symptoms. General satisfaction was observed overall in 80% of the patients. No adverse events were observed.
CONCLUSIONS
In this first study of a novel eyelid warming device, overall subjective satisfaction was reported in 80% of patients. Potential advantages of this user-friendly device include its ability to improve MGD and tear film stability, as well as symptomatic relief, while allowing the user to continue with normal daily functioning while undergoing treatment.
Topics: Male; Humans; Middle Aged; Aged; Aged, 80 and over; Meibomian Gland Dysfunction; Meibomian Glands; Eyelid Diseases; Prospective Studies; Hot Temperature
PubMed: 38420642
DOI: No ID Found -
BMJ Open Feb 2024The lipid layer of the tear film is critical to maintaining the integrity of the tear film and absence in the tear film lipid layer (TFLL) is one of the main causes of...
INTRODUCTION
The lipid layer of the tear film is critical to maintaining the integrity of the tear film and absence in the tear film lipid layer (TFLL) is one of the main causes of evaporative dry eye (EDE) in dry eye disease patients, resulting in excessive evaporation (so-called hyperevaporative dry eye). This study protocol will be designed to assess and compare the effects of intense pulsed light (IPL), heated eye mask (HEM), vectored thermal pulsation system (VTPS) and eyelid massage device (EMD) for improving signs and symptoms of EDE.
METHODS AND ANALYSIS
Patients with EDE will be randomly divided into IPL, HEM, VTPS and EMD groups and will be followed up for 6 weeks. The primary outcome measure will be non-invasive tear breakup time (NITBUT). The secondary outcome measures will include, TFLL score, meibomian gland quality and expressibility change from baseline conjunctivocorneal staining with fluorescein and lissamine, tear meniscus height, conjunctival hyperaemia (redness score) and ocular surface disease index questionnaire. Additionally, adverse events will be monitored and documented.
ETHICS AND DISSEMINATION
Ethics approval number: IRB(2023)K019.01. The findings will be shared regardless of the effect's direction.
TRIAL REGISTRATION NUMBER
NCT05923528.
Topics: Humans; Meibomian Glands; Dry Eye Syndromes; Tears; Fluorescein; Lipids; Randomized Controlled Trials as Topic
PubMed: 38413161
DOI: 10.1136/bmjopen-2023-078727 -
Indian Journal of Ophthalmology Jul 2024Dry eye syndrome (DES) is a familiar sequelae of radiation therapy (RT) for head and neck cancers (HNC). Ocular surface changes such as DES occur due to injury to the...
PURPOSE
Dry eye syndrome (DES) is a familiar sequelae of radiation therapy (RT) for head and neck cancers (HNC). Ocular surface changes such as DES occur due to injury to the conjunctival epithelium, goblet cells, corneal surface, lacrimal glands, and meibomian glands. This study aimed at the evaluation and early detection of changes in ocular surface parameters in patients receiving RT for extraocular HNC.
METHODS
Forty-two eyes of 21 patients undergoing HNC RT were evaluated. Radiation technique and dose of radiation to the lens and eye were recorded. Subjects were evaluated for meibomian gland changes by meiboscore grading, ocular surface disease index (OSDI) questionnaire, Schirmer's test, tear film break-up time (TBUT), and slit-lamp examination before RT, immediately post RT, and 6 weeks post RT. A comparison of the ipsilateral eye on the irradiated side to the contralateral eye was done.
RESULTS
A significant reduction in TBUT was seen immediately post RT and 6 weeks post RT ( P < 0.001 and 0.008, respectively), with an increase in meiboscore at both visits ( P < 0.001). An OSDI score of >13 was seen in 23.80% of patients post RT, with a significant difference from baseline ( P < 0.001). On comparing ipsilateral and contralateral eye groups, a significant difference from baseline was seen in TBUT ( P < 0.001 and 0.033, respectively) and meiboscore ( P < 0.001 for both eyes). A significant change of >1 second in TBUT and >1.7 in meiboscore was seen with a mean dose of around 8 Gy to the lens.
CONCLUSION
All patients undergoing HNC RT should be followed up for ocular surface and meibomian gland changes. The contralateral eye should also be evaluated. Patients receiving lower doses to the ocular structures should also be kept under follow-up.
Topics: Humans; Female; Male; Middle Aged; Dry Eye Syndromes; Head and Neck Neoplasms; Meibomian Glands; Tears; Aged; Follow-Up Studies; Adult; Radiation Injuries; Prospective Studies; Surveys and Questionnaires; Cornea; Slit Lamp Microscopy
PubMed: 38389244
DOI: 10.4103/IJO.IJO_1080_23