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Annals of Anatomy = Anatomischer... May 2024The ocular system is in constant interaction with the environment and with numerous pathogens. The ATP-binding cassette (ABC) transporters represent one of the largest...
The ocular system is in constant interaction with the environment and with numerous pathogens. The ATP-binding cassette (ABC) transporters represent one of the largest groups among the transmembrane proteins. Their relevance has been demonstrated for their defense function against biotic and abiotic stress factors, for metabolic processes in tumors and for their importance in the development of resistance to drugs. The aim of this study was to analyze which ABC transporters are expressed at the ocular surface and in the human lacrimal apparatus. Using RT-PCR, all ABC transporters known to date in humans were examined in tissue samples from human cornea, conjunctiva, meibomian glands and lacrimal glands. The RT-PCR analyses revealed the presence of all ABC transporters in the samples examined, although the results for some of the 48 transporters known in human and analyzed were different in the various tissues. The present results provide information on the expression of ABC transporters at the mRNA level on the ocular surface and in the lacrimal system. Their detection forms the basis for follow-up studies at the protein level, which will provide more information about their physiological significance at the ocular surface and in the lacrimal system and which may explain pathological effects such as drug resistance.
PubMed: 38697581
DOI: 10.1016/j.aanat.2024.152272 -
BMC Ophthalmology Apr 2024Evaluation of clinical efficacy and safety of tobramycin/dexamethasone eye ointment in treating persistent corneal epithelial dysfunction (PED) after cataract surgery.
OBJECTIVE
Evaluation of clinical efficacy and safety of tobramycin/dexamethasone eye ointment in treating persistent corneal epithelial dysfunction (PED) after cataract surgery.
METHODS
26 cases diagnosed as PED after cataract surgery accept the tobramycin/dexamethasone ophthalmic ointment and intense pulse light treatment in the Xiamen University of Xiamen eye center between September 2016 and April 2022 were retrospectively analyzed, mainly including clinical manifestations, characteristics of morphological changes imaged by in vivo confocal microscopy, meibomian glands infrared photography, lipid layer thickness (LLT), management and therapeutic effects.
RESULTS
There were 26 eyes, include 8(35%) males and 15(65%) females with an average age of 69.6 ± 5.2 years(50 to 78 years). The mean hospitalization time was (18.4 ± 7.5) days after cataract surgery. Twenty patients had meibomian gland dysfunction. Infrared photography revealed varying loss in the meibomian glands, with a mean score of 3.8 ± 1.2 for gland loss. The mean LLT was 61.6 ± 8.4 nm. After treatment, 20 patients were cured, and 3 received amniotic membrane transplantation. After treatment, the uncorrected visual acuity (UCVA) and best-corrected vision activity (BCVA) improved (P < 0.001), and there was no significant difference in intraocular pressure (IOP) before and after treatment (P > 0.05).
CONCLUSIONS
The early manifestation of PED after surgery is punctate staining of the corneal epithelium. Tobramycin and dexamethasone eye ointment bandages have a good repair effect. The meibomian gland massage combined with intense pulse light treatment can effectively shorten the course of the disease.
Topics: Humans; Female; Male; Aged; Middle Aged; Dexamethasone; Retrospective Studies; Epithelium, Corneal; Visual Acuity; Tobramycin; Glucocorticoids; Cataract Extraction; Corneal Diseases; Anti-Bacterial Agents; Microscopy, Confocal; Postoperative Complications; Ointments
PubMed: 38671418
DOI: 10.1186/s12886-024-03466-x -
International Journal of Molecular... Apr 2024While the involvement of thermosensitive transient receptor potential channels (TRPs) in dry eye disease (DED) has been known for years, their expression in the...
While the involvement of thermosensitive transient receptor potential channels (TRPs) in dry eye disease (DED) has been known for years, their expression in the meibomian gland (MG) has never been investigated. This study aims to show their expression and involvement in the lipogenesis of the MG, providing a possible new drug target in the treatment of DED. Our RT-PCR, Western blot and immunofluorescence analysis showed the expression of , , and in the MG at the gene and the protein level. RT-PCR also showed gene expression of but not . Calcium imaging and planar patch-clamping performed on an immortalized human meibomian gland epithelial cell line (hMGECs) demonstrated increasing whole-cell currents after the application of capsaicin (TRPV1) or icilin (TRPM8). Decreasing whole-cell currents could be registered after the application of AMG9810 (TRPV1) or AMTB (TRPM8). Oil red O staining on hMGECs showed an increase in lipid expression after TRPV1 activation and a decrease after TRPM8 activation. We conclude that thermo-TRPs are expressed at the gene and the protein level in MGs. Moreover, TRPV1 and TRPM8's functional expression and their contribution to their lipid expression could be demonstrated. Therefore, TRPs are potential drug targets and their clinical relevance in the therapy of meibomian gland dysfunction requires further investigation.
Topics: Humans; Meibomian Glands; Lipogenesis; Meibomian Gland Dysfunction; Blotting, Western; Capsaicin
PubMed: 38612853
DOI: 10.3390/ijms25074043 -
BMJ Open Ophthalmology Apr 2024The objective of this study is to determine the validity and reliability of the red filter meibography by smartphone compared with infrared in assessing meibomian gland...
OBJECTIVE
The objective of this study is to determine the validity and reliability of the red filter meibography by smartphone compared with infrared in assessing meibomian gland drop-out.
METHODS AND ANALYSIS
An analytical cross-sectional study was done with a total of 35 subjects (68 eyes) with suspected MGD based on symptoms and lid morphological abnormalities. Meibomian glands were photographed using two smartphones (Samsung S9 and iPhone XR) on a slit-lamp with added red filter. Images were assessed subjectively using meiboscore by the two raters and drop-out percentages were assessed by ImageJ.
RESULTS
There was no agreement in meiboscore and a minimal level of agreement in drop-out percentages between red filter meibography and infrared. Inter-rater reliability showed no agreement between two raters. Intra-rater reliability demonstrated weak agreement in rater 1 and no agreement in rater 2.
CONCLUSION
Validity of the red filter meibography technique by smartphones is not yet satisfactory in evaluating drop-out. Further improvement on qualities of images must be done and research on subjective assessment was deemed necessary due to poor results of intrarater and inter-rater reliability.
Topics: Humans; Meibomian Gland Dysfunction; Smartphone; Cross-Sectional Studies; Reproducibility of Results; Meibomian Glands
PubMed: 38609325
DOI: 10.1136/bmjophth-2023-001266 -
International Journal of Molecular... Mar 2024Meibomian gland dysfunction (MGD) is one of the main causes of dry eye disease. To better understand the physiological functions of human meibomian glands (MGs), the...
Comparative Characterization of Human Meibomian Glands, Free Sebaceous Glands, and Hair-Associated Sebaceous Glands Based on Biomarkers, Analysis of Secretion Composition, and Gland Morphology.
Meibomian gland dysfunction (MGD) is one of the main causes of dry eye disease. To better understand the physiological functions of human meibomian glands (MGs), the present study compared MGs with free sebaceous glands (SGs) and hair-associated SGs of humans using morphological, immunohistochemical, and liquid chromatography-mass spectrometry (LCMS)-based lipidomic approaches. Eyelids with MGs, nostrils, lips, and external auditory canals with free SGs, and scalp with hair-associated SGs of body donors were probed with antibodies against cytokeratins (CK) 1, 8, 10, and 14, stem cell markers keratin 15 and N-cadherin, cell-cell contact markers desmoglein 1 (Dsg1), desmocollin 3 (Dsc3), desmoplakin (Dp), plakoglobin (Pg), and E-cadherin, and the tight junction protein claudin 5. In addition, Oil Red O staining (ORO) was performed in cryosections. Secretions of MGs as well as of SGs of nostrils, external auditory canals, and scalps were collected from healthy volunteers, analyzed by LCMS, and the data were processed using various multivariate statistical analysis approaches. Serial sections of MGs, free SGs, and hair-associated SGs were 3D reconstructed and compared. CK1 was expressed differently in hair-associated SGs than in MGs and other free SGs. The expression levels of CK8, CK10, and CK14 in MGs were different from those in hair-associated SGs and other free SGs. KRT15 was expressed differently in hair-associated SGs, whereas N-cadherin was expressed equally in all types of glands. The cell-cell contact markers Dsg1, Dp, Dsc3, Pg, and E-cadherin revealed no differences. ORO staining showed that lipids in MGs were more highly dispersed and had larger lipid droplets than lipids in other free SGs. Hair-associated SGs had a smaller number of lipid droplets. LCMS revealed that the lipid composition of meibum was distinctively different from that of the sebum of the nostrils, external auditory canals, and scalp. The 3D reconstructions of the different glands revealed different morphologies of the SGs compared with MGs which are by far the largest type of glands. In humans, MGs differ in their morphology and secretory composition and show major differences from free and hair-associated SGs. The composition of meibum differs significantly from that of sebum from free SGs and from hair-associated SGs. Therefore, the MG can be considered as a highly specialized type of holocrine gland that exhibits all the histological characteristics of SGs, but is significantly different from them in terms of morphology and lipid composition.
Topics: Humans; Meibomian Glands; Sebaceous Glands; Tears; Biomarkers; Lipids; Cadherins
PubMed: 38542083
DOI: 10.3390/ijms25063109 -
Investigative Ophthalmology & Visual... Mar 2024To validate the adenosine triphosphate (ATP)-binding cassette transporter A1 (ABCA1) expression and distribution in human eyelid tissues and meibomian gland epithelial...
PURPOSE
To validate the adenosine triphosphate (ATP)-binding cassette transporter A1 (ABCA1) expression and distribution in human eyelid tissues and meibomian gland epithelial cells.
METHODS
Meibomian gland tissues from human eyelids were isolated by collagenase A digestion and cultured in defined keratinocyte serum-free medium (DKSFM). Infrared imaging was used to analyze the general morphology of meibomian glands. Hematoxylin and eosin (H&E) staining and Oil Red O staining were used to observe the morphological structure and lipid secretion in the human meibomian gland tissues. Quantitative real-time polymerase chain reaction, western blotting, and immunostaining were used to detect the mRNA and protein expression and cytolocalization of ABCA1 in the meibomian gland tissues and cultured cells.
RESULTS
The degree of loss of human meibomian gland tissue was related to age. Meibomian gland lipid metabolism was also associated with age. Additionally, human meibomian gland tissues express ABCA1 mRNA and protein; glandular epithelial cells express more ABCA1 mRNA and protein than acinar cells, and their expression in acinar cells decreases with differentiation. Furthermore, the expression of ABCA1 was downregulated in abnormal meibomian gland tissues. ABCA1 was mainly localized on the cell membrane in primary human meibomian gland epithelial cells (pHMGECs), whereas it was localized in the cytoplasm of immortalized human meibomian gland epithelial cells (iHMGECs). The mRNA and protein levels of ABCA1 in pHMGECs were higher than those in iHMGECs.
CONCLUSIONS
Meibomian gland tissues of the human eyelid degenerate with age. ABCA1 expression in acinar cells decreases after differentiation and plays an important role in meibomian gland metabolism.
Topics: Humans; Meibomian Glands; Epithelial Cells; Adenosine Triphosphate; Blotting, Western; Membrane Transport Proteins; RNA, Messenger; ATP Binding Cassette Transporter 1
PubMed: 38502139
DOI: 10.1167/iovs.65.3.24 -
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