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Nguyen A, Naidoo KK, Ajouz L, Xu X, Zhao C, Robinson MR, Borchman D. Changes in Human Meibum Lipid Composition Related to the Presence and Severity of Meibomian Gland Dysfunction. J Ocul Pharmacol Ther 2024. [PMID: 39150383 DOI: 10.1089/jop.2024.0063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/17/2024] Open
Abstract
Purpose: Changes in meibum composition and quantity in meibomian gland dysfunction (MGD) result in tear film instability and dry eye. This exploratory study aimed to identify changes in (O-acyl)-ω-hydroxy fatty acid (OAHFA) and hydrocarbon chain (HC) unsaturation levels in meibum related to the presence and severity of MGD. Methods: Meibum samples were collected from 3 cohorts of adults with no MGD, mild-to-moderate MGD, and severe MGD in a noninterventional clinical trial (NCT01979887). OAHFAs, cholesterol esters (CE), HC unsaturation, and HC length in the meibum samples were quantified with 1H-nuclear magnetic resonance spectroscopy using 2 methods of normalization. Results: Meibum samples from 62 subjects were analyzed: 21 non-MGD, 21 mild-to-moderate MGD, and 20 severe MGD. Meibum OAHFA and CE levels and HC unsaturation were reduced with increasing severity of MGD, with most pairwise comparisons significant (P < 0.05, t-tests), following the order non-MGD > mild-to-moderate MGD > severe MGD. Regardless of the resonances used for normalization, each pairwise comparison of OAHFA, CE, and HC unsaturation levels in MGD (combined severities) versus non-MGD samples was significant (P < 0.01, t-test). Analysis using various normalization equations showed reductions of 20%-22% for OAHFAs, 51%-57% for CE, and 36%-66% for HC unsaturation in MGD (combined severities) compared with non-MGD. HC length was not altered in MGD (combined severities) compared with non-MGD samples (t-test). Conclusions: Meibum OAHFA, CE, and HC unsaturation levels were reduced in MGD and were lowest in the severe MGD cohort. These findings may contribute to the understanding of the pathophysiology of MGD.
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Affiliation(s)
- Ashley Nguyen
- Allergan, an AbbVie company, Irvine, California, USA
| | - Kugen K Naidoo
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, Kentucky, USA
| | - Layla Ajouz
- Allergan, an AbbVie company, Irvine, California, USA
| | - Xiaoming Xu
- Allergan, an AbbVie company, Irvine, California, USA
| | - Cathy Zhao
- Allergan, an AbbVie company, Irvine, California, USA
| | | | - Douglas Borchman
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, Kentucky, USA
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Zhao W, Yang J, Liao Y, Yang B, Lin S, Liu R, Liang L. Alteration of Meibum Lipidomics Profiling in Patients With Chronic Ocular Graft-Versus-Host Disease. Invest Ophthalmol Vis Sci 2023; 64:35. [PMID: 37733365 PMCID: PMC10517420 DOI: 10.1167/iovs.64.12.35] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 08/15/2023] [Indexed: 09/22/2023] Open
Abstract
Purpose To investigate the characteristics of the lipid profiling in meibum of patients with chronic ocular graft-versus-host disease (coGVHD) and to detect the potential influence of anti-inflammatory therapy on these differential lipids. Methods This cross-sectional study included 25 coGVHD patients and 13 non-coGVHD after allogeneic hematopoietic stem cell transplantation. Among those with coGVHD, 14 had prior topical treatment (coGVHD(T)), and 11 did not (coGVHD(WT)). All participants completed ocular surface disease index questionnaire and received slit lamp examination, Schirmer's test without anesthesia, ocular surface interferometer, and meibography. Binocular meibum was collected and pooled for lipidomic analysis by liquid chromatography-mass spectrometry. Results One hundred and twenty differential lipid species were found among the three groups (96 of coGVHD(WT) vs. non-coGVHD, 78 of coGVHD(WT) vs. coGVHD(T), and three of non-coGVHD vs. coGVHD(T)). Compared with non-coGVHD group, coGVHD(WT) group had a significant abnormality of meibum composition, showing a significant decrease in glycerolipids, and an increase in glycerophospholipids and sphingolipids. Similar changes were also observed when coGVHD(WT) versus coGVHD(T). CoGVHD severity was negatively associated with mono-unsaturated triglycerides (TG), (β = -214.7; 95% CI, -363.9 to -65.5; P = 0.006) and poly-unsaturated TG (β = -4019.9; 95% CI, -7758.1 to -281.6; P = 0.036). Intensity of immunosuppression was negatively associated with mono-unsaturated TG (β = -162.4; 95% CI, -268.6 to -56.2; P = 0.004) and positively associated with phosphatidylcholine (β = 332.0; 95% CI, 19.2-644.8; P = 0.038). Conclusions Altered meibum in coGVHD is characterized by a decrease of glycerolipids and an increase of glycerophospholipids and may be significantly reversed by topical anti-inflammatory therapy.
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Affiliation(s)
- Wenxin Zhao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Jing Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Yinglin Liao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Boyu Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Shujiao Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Ren Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Lingyi Liang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
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Jung GT, Kim M, Song JS, Kim TI, Chung TY, Choi CY, Kim HS, An WJ, Jeong SJ, Lee HS, Jeon S, Kim KP, Lee HK. Proteomic analysis of tears in dry eye disease: A prospective, double-blind multicenter study. Ocul Surf 2023; 29:68-76. [PMID: 37094778 DOI: 10.1016/j.jtos.2023.04.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 03/19/2023] [Accepted: 04/20/2023] [Indexed: 04/26/2023]
Abstract
PURPOSE To identify specific dry eye disease (DED) tear biomarker(s) using tear proteomic analysis, clinical parameters, and their correlations before and after DED treatment. METHODS A prospective, double-blinded, national multicenter clinical study was performed using data from 80 DED patients. The patients were treated with 0.1% cyclosporine (CsA, n = 28), 0.05% CsA (n = 26), or 3% diquafosol (DQS, n = 26) eye drops, and tear proteome changes and clinical outcomes (tear break-up time [TBUT], corneal erosion [Cor-Er], conjunctival erosion [Conj-Er], and symptom assessment in dry eye [SANDE] scores) were observed at 4, 8, and 12 weeks. For all clinical parameters, correlation analysis was performed between the three drug conditions and the differentially expressed proteins (DEPs) from the proteomic analysis. RESULTS AFM, ALCAM, CFB, H1-4, PON1, RAP1B, and RBP4 were identified in all treatment groups and were downregulated after treatment. All clinical parameters significantly improved at 12 weeks than at baseline (p-value <0.0001); however, their values were not significantly different among groups, except for Cor-Er (p-value = 0.007). Compared with the DQS group, Cor-Er score significantly improved after treatment with 0.1% and 0.05% CsA. The seven DEPs identified in all groups were not consistently correlated with the clinical parameters (p-value >0.05). CONCLUSIONS Despite differences in drug concentration and action mechanisms, the improvement levels of TBUT, Cor-Er, and SANDE scores were clinically adequate. However, useful tear protein biomarkers, clinically acceptable biomarker combinations correlating with clinical parameters, and clinically acceptable levels of specificity and sensitivity were not identified.
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Affiliation(s)
- Gun Tae Jung
- Department of Biomedical Science and Technology, Kyung Hee Medical Science Research Institute, Kyung Hee University, Seoul, Republic of Korea
| | - Minha Kim
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Jong Suk Song
- Department of Ophthalmology, Korea University College of Medicine, Seoul, Republic of Korea
| | - Tae Im Kim
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Tae Young Chung
- College of Pharmacy, Yonsei University, Seoul, Republic of Korea
| | - Chul Young Choi
- Department of Ophthalmology, School of Medicine, Sungkyunkwan University, Seoul, Republic of Korea
| | - Hyun Seong Kim
- Department of Ophthalmology, Catholic University College of Medicine, Seoul, Republic of Korea
| | - Woo Ju An
- Department of Applied Chemistry, Institute of Natural Science, Global Center for Pharmaceutical Ingredient Materials, Kyung Hee University, Yongin, Republic of Korea
| | - Su Jin Jeong
- Department of Statistics Support, Medical Science Research Institute, Kyung Hee University Hospital, Seoul, Republic of Korea
| | - Hye Sun Lee
- Biostatistics Collaboration Unit, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Soyoung Jeon
- Biostatistics Collaboration Unit, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Kwang Pyo Kim
- Department of Biomedical Science and Technology, Kyung Hee Medical Science Research Institute, Kyung Hee University, Seoul, Republic of Korea; Department of Applied Chemistry, Institute of Natural Science, Global Center for Pharmaceutical Ingredient Materials, Kyung Hee University, Yongin, Republic of Korea.
| | - Hyung Keun Lee
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Republic of Korea; College of Pharmacy, Yonsei University, Seoul, Republic of Korea.
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Sheppard JD, Nichols KK. Dry Eye Disease Associated with Meibomian Gland Dysfunction: Focus on Tear Film Characteristics and the Therapeutic Landscape. Ophthalmol Ther 2023; 12:1397-1418. [PMID: 36856980 PMCID: PMC10164226 DOI: 10.1007/s40123-023-00669-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 01/27/2023] [Indexed: 03/02/2023] Open
Abstract
Meibomian gland dysfunction (MGD) is highly prevalent and is the leading cause of evaporative dry eye disease (DED). MGD is characterized by a reduction in meibum secretion and/or a change in meibum composition that results in the disruption of the tear film lipid layer and an increase in the tear film evaporation rate. Excessive evaporation causes tear film instability, desiccation, tear hyperosmolarity, inflammation, and apoptosis of ocular surface cells, resulting in a continuous cycle of DED. The primary treatment goal for DED associated with MGD is to restore the tear film lipid layer and decrease evaporation, thereby reducing ocular signs and symptoms. The management of MGD includes home care options (eyelid hygiene, warming eye masks, ocular lubricants) and office-based treatments (manual expression, microblepharoexfoliation, thermal pulsation, intense pulsed light, intraductal probing). Topical ophthalmic prescription medications attempt to alter various factors that may contribute to DED (e.g., inflammation, bacterial growth, inadequate tear production). In this review, clinical evidence regarding available treatments and emerging therapies from randomized studies in patients with DED associated with MGD is summarized. Although some treatment modalities have been evaluated specifically for DED patients with MGD, large-scale randomized controlled trials are needed to confirm efficacy and safety in this patient population. Currently, there are no approved prescription pharmacologic treatments specifically indicated for DED associated with MGD, and those medications approved for the treatment of DED do not target the key driver of the disease (i.e., excessive evaporation). NOV03 (perfluorohexyloctane; under review with the US Food and Drug Administration) is the most advanced emerging therapy for DED associated with MGD and has demonstrated statistically significant improvements in both signs and symptoms in randomized controlled trials. Development of novel pharmacotherapies will improve therapeutic options and allow for a more individualized approach for patients with DED associated with MGD.
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Affiliation(s)
- John D Sheppard
- Virginia Eye Consultants and Eastern Virginia Medical School, Suite #210, 241 Corporate Blvd, Norfolk, VA, 23502, USA. .,Eyecare Partners, St. Louis, MO, USA.
| | - Kelly K Nichols
- School of Optometry, University of Alabama at Birmingham, Birmingham, AL, USA
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Topical Review: Optometry in Nepal-Clinical Practice, Research Advances, and Challenges. Optom Vis Sci 2023; 100:134-142. [PMID: 36728818 DOI: 10.1097/opx.0000000000001980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
SIGNIFICANCE This article reviews educational standard, clinical practice, research advances, and challenges associated with optometry in Nepal and provides critical considerations for contemporary and new optometry programs in countries with similar socioeconomic status and health care systems.Optometry education started in Nepal in 1998 with the primary objective of addressing the unmet needs of eye health and vision care in the country. Over the last two decades, this program has made significant contributions to facilitating and improving the delivery of quality eye care and establishing the nation's eye health system as an exemplary model in South Asia. Despite the positive impact in a short time, optometry education and the profession continue to face several challenges, including a shortage of training resources and facilities, poor quality control and regulation of practice standards, lack of professional recognition, limited pathways for entry to governmental jobs via the national public service commission, and limited clinical and academic opportunities in existing eye care programs. This article reviews current education and clinical practice standards, highlights research advances, and discusses present and future challenges in sustaining and improving the quality of education and advancing the scope of practice of optometry in Nepal. Given the limited access to primary eye care services in Nepal, appropriate professional recognition and integration into the national health system, and initiatives targeted at improving the delivery of optometry education in alignment with successful international models may provide a long-sought solution to making eye care services accessible to all and lowering the burden of visual impairment in the country.
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Asiedu K. Candidate Molecular Compounds as Potential Indicators for Meibomian Gland Dysfunction. Front Med (Lausanne) 2022; 9:873538. [PMID: 35685417 PMCID: PMC9170961 DOI: 10.3389/fmed.2022.873538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 04/08/2022] [Indexed: 11/16/2022] Open
Abstract
Meibomian gland dysfunction (MGD) is the leading cause of dry eye disease throughout the world. Studies have shown that several molecules in meibum, including but not limited to interleukins, amino acids, cadherins, eicosanoids, carbohydrates, and proteins, are altered in meibomian gland dysfunction compared with healthy normal controls. Some of these molecules such as antileukoproteinase, phospholipase A2, and lactoperoxidase also show differences in concentrations in tears between meibomian gland dysfunction and dry eye disease, further boosting hopes as candidate biomarkers. MGD is a complex condition, making it difficult to distinguish patients using single biomarkers. Therefore, multiple biomarkers forming a multiplex panel may be required. This review aims to describe molecules comprising lipids, proteins, and carbohydrates with the potential of serving various capacities as monitoring, predictive, diagnostic, and risk biomarkers for meibomian gland dysfunction.
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Suárez-Cortés T, Merino-Inda N, Benitez-Del-Castillo JM. Tear and ocular surface disease biomarkers: A diagnostic and clinical perspective for ocular allergies and dry eye disease. Exp Eye Res 2022; 221:109121. [PMID: 35605673 DOI: 10.1016/j.exer.2022.109121] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 04/30/2022] [Accepted: 05/16/2022] [Indexed: 11/04/2022]
Abstract
Validated biomarkers to be used as biological tools for managing ocular surface diseases (OSDs) are still an unmet need in daily clinical practice. Many studies have contributed to the already extensive list of candidate biomarkers for these disorders. Dry eye (DE) and ocular allergy (OA) are complex and multifactorial diseases, often coexisting and with overlapping symptoms. The purpose of this review is to present a comprehensive updated revision of the most relevant biomarkers of DE and OA, with an emphasis on quantitative analyses and correlations with clinical parameter data. Analysis of biomarkers common for these pathologies has highlighted an important physiological process. Namely, the interleukin proteins (IL-1α, IL-1β and IL-17), tumour necrotic factor (TNFα) and interferon gamma (IFNγ; Th1-Th7 pathway) and IL-4, IL-5 and IL-13 (Th2 pathway) seem to represent similar inflammatory mechanisms. Moreover, changes in the levels of mucins (MUC1, MUC2, MUC4, MUC5 and MUC16) are common alterations in the tear film mucous layer. We also examine the current state of medical devices and the main limitations to their use in clinical practice. Translational research in biomarkers for clinical practice depends on a feasible transition from the laboratory to the point-of-care. This requires large-scale, coordinated clinical validation campaigns to select the biomarkers with the highest specificity and sensitivity and significant correlation with clinical parameters. Moreover, technical limitations of multiplexed quantitation systems must be overcome to detect and measure the levels of several biomarkers in very small samples. To ensure the future of biomarker research, significant progress is necessary in a number of fields. There is an urgent need for global unification of clinical classification and diagnostics criteria. Widespread integration of proteomic and transcriptomic data is paramount for performing meaningful analyses using appropriate bioinformatics tools and artificial intelligence systems.
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Biophysical properties of tear film lipid layer II. Polymorphism of FAHFA. Biophys J 2022; 121:451-458. [PMID: 34968427 PMCID: PMC8822609 DOI: 10.1016/j.bpj.2021.12.034] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 12/04/2021] [Accepted: 12/22/2021] [Indexed: 02/03/2023] Open
Abstract
Fatty acid esters of hydroxy fatty acids (FAHFAs) are a newly discovered class of endogenous lipids that consist of two acyl chains connected through a single ester bond. Being a unique species of FAHFAs, (O-acyl)-ω-hydroxy fatty acids (OAHFAs) differ from other FAHFAs in that their hydroxy fatty acid backbones are ultralong and their hydroxy esterification is believed to be solely at the terminal (ω-) position. Only in recent years with technological advances in lipidomics have OAHFAs been identified as an important component of the tear film lipid layer (TFLL). It was found that OAHFAs account for approximately 4 mol% of the total lipids and 20 mol% of the polar lipids in the TFLL. However, their biophysical function and contribution to the TFLL is still poorly understood. Here we studied the molecular biophysical mechanisms of OAHFAs using palmitic-acid-9-hydroxy-stearic-acid (PAHSA) as a model. PAHSA and OAHFAs share key structural similarities that could result in comparable biophysical properties and molecular mechanisms. With combined biophysical experiments, atomic force microscopy observations, and all-atom molecular dynamics simulations, we found that the biophysical properties of a dynamic PAHSA monolayer under physiologically relevant conditions depend on a balance between kinetics and thermal relaxation. PAHSA molecules at the air-water surface demonstrate unique polymorphic behaviors, which can be explained by configurational transitions of the molecules under various lateral pressures. These findings could have novel implications in understanding biophysical functions that FAHFAs, in general, or OAHFAs, specifically, play in the TFLL.
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Human meibum and tear film derived cholesteryl and wax esters in meibomian gland dysfunction and tear film structure. Ocul Surf 2022; 23:12-23. [PMID: 34774809 PMCID: PMC9875797 DOI: 10.1016/j.jtos.2021.10.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 10/27/2021] [Accepted: 10/29/2021] [Indexed: 02/07/2023]
Abstract
PURPOSE This study evaluated the presence and roles of cholesteryl esters (CEs) and wax esters (WEs) from human tear film and meibum in meibomian gland dysfunction (MGD). METHODS Out of 195 enrolled subjects, 164 and 179 subjects provided tear and meibum samples, respectively. Subjects were classified into normal, asymptomatic MGD, MGD, and mixed (MGD & aqueous deficient). The precorneal tear film (PCTF) thinning rate (evaporation) was measured using optical coherence tomography. Lipids extracted from tear and meibum samples were infused into a SCIEX 5600 TripleTOF mass spectrometer. CE and WE intensities quantified with Analyst 1.7 TF and LipidView 1.3 were compared across disease groups in MetaboAnalyst 5.0 and correlated with PCTF thinning rates. RESULTS The numbers of unique CEs and WEs identified in the samples were 125 and 86, respectively. Unsupervised Principal Component (PC) analysis and supervised Partial Least Square Discriminant analysis exhibited little separation among groups for both CEs and WEs in tears and meibum. Spearman's correlation analyses showed no association between either the first or second PC scores with PCTF thinning rates. CONCLUSION The abundances of human PCTF and meibum-derived CEs and WEs were independent of MGD disease status and PCTF thinning (evaporation). CEs and WEs alterations do not contribute to alterations in tear film dynamics in MGD, such as has been demonstrated by the (O-acyl) ω-hydroxy fatty acids (OAHFAs).
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Bai Y, Ngo W, Khanal S, Nichols JJ. Characterization of the thickness of the Tear Film Lipid Layer in Meibomian Gland Dysfunction using high resolution optical microscopy. Ocul Surf 2021; 24:34-39. [PMID: 34968765 DOI: 10.1016/j.jtos.2021.12.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 12/21/2021] [Accepted: 12/23/2021] [Indexed: 12/19/2022]
Abstract
PURPOSE To evaluate the thickness of the tear film lipid layer (TFLL) in meibomian gland dysfunction (MGD) using a high-resolution optical microscope. METHODS The Ocular Surface Disease Index (OSDI) and meibum grade score (MGS) were used to classify 190 subjects into four groups: normal (OSDI<13 and MGS<10), mixed (OSDI≥13 and MGS<10), asymptomatic MGD (OSDI<13 and MGS≥10), and MGD (OSDI≥13 and MGS≥10). The high-resolution optical microscope was used to capture TFLL images in vivo. The histograms of TFLL thickness were analyzed and curve-fitted using probability density functions (PDFs). RESULTS There were three obvious peaks in the distributions of TFLL across the groups. From the curve-fitting process, the main outcomes are displayed according to each Gaussian function with the position of peak (μ) and the summed percentage within the range of standard deviation (σ). The normal group had distribution as follows: 33.3 ± 0.005 nm, 26%; 53.9 ± 0.019 nm, 40%; 79.4 ± 0.064 nm, 12%. The mixed group had a distribution as follows: 33.8 ± 0.004 nm, 32%; 53.1 ± 0.115 nm, 21%; 71.7 ± 0.232 nm, 27%. The asymptomatic MGD group had a distribution as follows: 33.5 ± 0.004 nm, 20%; 49.2 ± 0.041 nm, 25%; 62.9 ± 0.063 nm, 47%. The MGD group had a distribution as follows: 34.3 ± 0.004 nm, 34%; 53.7 ± 0.022 nm, 28%; 74.9 ± 0.060 nm, 16%. CONCLUSIONS The MGD and mixed groups had the largest percentages of TFLL thicknesses fall within the thinnest modes (peak 34.3 and 33.8 nm, respectively). These data show that measures of central tendency (e.g., averages, medians) do not fully appreciate the variable distributions of TFLL across disease spectra.
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Affiliation(s)
- Yuqiang Bai
- Department of Optometry and Vision Science, School of Optometry, University of Alabama at Birmingham, Birmingham, AL, USA
| | - William Ngo
- Centre for Ocular Research & Education, School of Optometry & Vision Science, University of Waterloo, Waterloo, Ontario, Canada; Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Hong Kong
| | - Safal Khanal
- Department of Optometry and Vision Science, School of Optometry, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jason J Nichols
- Department of Optometry and Vision Science, School of Optometry, University of Alabama at Birmingham, Birmingham, AL, USA.
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Gao H, Chen H, Xie HT, Xu KK, Shi BJ, Huang YK. Changes in Meibum Lipid Composition With Ocular Demodex Infestation. Transl Vis Sci Technol 2021; 10:6. [PMID: 34874449 PMCID: PMC8662575 DOI: 10.1167/tvst.10.14.6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Purpose The purpose of this study was to understand the impact of Demodex infection in the lipid component of meibum in patients. Methods The meibum samples were collected from four groups of subjects: (1) Demodex-negative with non-MGD (D−M−; n = 10); (2) Demodex-positive with non-MGD (D+M−; n = 10); (3) Demodex-negative with MGD (D−M+; n = 10); and (4) Demodex-positive with MGD (D+M+; n = 10). A liquid chromatography–mass spectrometry (LC-MS) system consisting of ultra-performance liquid chromatography and a Q Exactive high-resolution mass spectrometer was used for lipids separation and detection. Results Compared with the D−M− group, the D+M− group had lower levels of phosphatidylcholines (PCs) and lysophosphatidylcholines (LPCs) and higher levels of phosphatidylethanolamines (PEs). Compared with the D−M+ group, the levels of sphingomyelins (SMs) and PCs in the D+M+ group were decreased, whereas the levels of (O-acyl)-ω-hydroxy fatty acids (OAHFAs), ceramides (CERs), LPCs, and diacylglycerols (DGs) were significantly increased. Triacylglycerols (TGs), DGs, CERs, and OAHFAs were decreased in D−M+ group, whereas levels of PEs, phosphatidylinositols, and phosphatidylglycerols were increased in meibum obtained from the D−M+ group compared with those in the D−M− group. TGs, SMs, CERs, and PEs were decreased in the D+M+ group, whereas levels of LPCs, LPEs, PCs, and PEs were increased in meibum from the D−M+ group compared with those in the D+M− group. Conclusions To the best of our knowledge, this is the first study to assess the changes in meibum from patients with ocular Demodex infestation. The significant increase of OAHFAs in the Demodex-positive group suggest that OAHFAs may be associated with the progress of ocular Demodex infections. Translational Relevance OAHFAs could be a potential new therapeutic target for ocular Demodex infestation.
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Affiliation(s)
- Hui Gao
- Department of Ophthalmology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Aier Eye Hospital of Wuhan University, Wuhan, China
| | - Hua Chen
- Department of Ophthalmology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hua-Tao Xie
- Department of Ophthalmology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Kang-Kang Xu
- Department of Ophthalmology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Bing-Jie Shi
- Department of Ophthalmology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yu-Kan Huang
- Department of Ophthalmology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Phan MAT, Madigan MC, Stapleton F, Willcox M, Golebiowski B. Human meibomian gland epithelial cell culture models: Current progress, challenges, and future directions. Ocul Surf 2021; 23:96-113. [PMID: 34843998 DOI: 10.1016/j.jtos.2021.11.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 11/04/2021] [Accepted: 11/23/2021] [Indexed: 12/13/2022]
Abstract
The widely used immortalised human meibomian gland epithelia cell (iHMGEC) line has made possible extensive studies of the biology and pathophysiology of meibomian glands (MG). Tissue culture protocols for iHMGEC have been revised and modified to optimise the growth conditions for cell differentiation and lipid accumulation. iHMGEC proliferate in serum-free medium but require serum or other appropriate exogenous factors to differentiate. Several supplements can enhance differentiation and neutral lipid accumulation in iHMGEC grown in serum-containing medium. In serum-free medium, rosiglitazone, a peroxisome proliferator activator receptor-γ (PPARγ) agonist, is reported to induce iHMGEC differentiation, neutral lipid accumulation and expression of key biomarkers of differentiation. iHMGEC cultured in serum-containing medium under hypoxia or with azithromycin increases DNAse 2 activity, a biomarker of terminal differentiation in sebocytes. The production of lipids with composition similar to meibum has not been observed in vitro and this remains a major challenge for iHMGEC culture. Innovative methodologies such as 3D ex vivo culture of MG and generation of MG organoids from stem cells are important for further developing a model that more closely mimics the in vivo biology of human MG and to facilitate the next generation of studies of MG disease and dry eye.
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Affiliation(s)
- Minh Anh Thu Phan
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW Sydney, NSW, 2033, Australia.
| | - Michele C Madigan
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW Sydney, NSW, 2033, Australia
| | - Fiona Stapleton
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW Sydney, NSW, 2033, Australia
| | - Mark Willcox
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW Sydney, NSW, 2033, Australia
| | - Blanka Golebiowski
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW Sydney, NSW, 2033, Australia
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