Structural and Molecular Tear Film Changes in Glaucoma

2019 ◽  
Vol 26 (22) ◽  
pp. 4225-4240 ◽  
Author(s):  
Rodolfo Mastropasqua ◽  
Luca Agnifili ◽  
Leonardo Mastropasqua
Keyword(s):  
Ocular Surface ◽  
Tear Film ◽  
Meibomian Gland ◽  
Eye Drops ◽  
Potential Candidate ◽  
Lipid Layer ◽  
Inflammatory Status ◽  
Quality Of Vision ◽  
Aqueous Layer

: The Tear Film (TF) is a trilaminar and dynamic fluid covering the entire Ocular Surface (OS), consisting of a mucus, aqueous, and lipid layer deeply interacting between them. Because of its structure and functions, TF plays a pivotal role in the preservation of the OS integrity and the quality of vision. Medical therapy for glaucoma is recognized to profoundly disturb the OS homeostasis by altering all components of the ocular surface unit, including TF. The presence of preservatives, the number of daily eye drops instillations, and the duration of therapy are the main contributors to TF changes. From the physio-pathological side, TF alterations are induced by toxic and allergic mechanisms and result from goblet cell and Meibomian gland loss, dysfunction of accessory lacrimal glands, and epithelial disruption. : In detail, TF changes are represented by mucus layer thinning, reduced mucin concentration, aqueous layer volume reduction, and lipid layer thinning with increased tear evaporation. Hyper- osmolarity and instability represent the main hallmarks of these changes and are an expression of a iatrogenic form of dry eye. TF undergoes also molecular modifications that primarily reflect a therapy- or disease-induced inflammatory status of the OS. Over the last years, this field of research aimed a progressively growing interest since molecular variations may be considered as potential candidate biomarkers of glaucoma. The aim of this review is to report the main TF changes occurring during glaucoma, exploring the relationship they may have with the glaucoma-related ocular surface disease and the patient quality of life, and their utility as potential biomarkers of disease.

scholarly journals Zdravljenje glavkoma in suho oko

2016 ◽  
Vol 85 (4) ◽  
Author(s):  
Barbara Cvenkel
Keyword(s):  
Ocular Surface ◽  
Clinical Signs ◽  
Tear Film ◽  
Signs And Symptoms ◽  
Surface Damage ◽  
Eye Drops ◽  
Film Instability ◽  
Asymptomatic Patients

Patients with glaucoma have increased prevalence of dry eye (DE) compared to age-matched population without glaucoma. Clinical presentation of DE varies among individuals and may significantly reduce quality of life. The onset and deterioration of DE is caused by the toxic-inflammatory effects of preservatives in eye drops, active substance itself, and added, pharmacologically inactive substances or excipients. Ocular surface changes most frequently include superficial punctate keratitis, tear film instability, and allergic reactions. Despite the lack of symptoms, clinical signs may indicate ocular surface damage. Discordance between signs and symptoms is partly caused by decreased corneal sensitivity induced by neurotoxicity of the preservative benzalkonium chloride (BAK). Therefore, it is important to evaluate ocular surface before initiating glaucoma therapy and during follow-up also in asymptomatic patients. Preservative-free and/or BAK-free therapy is indicated in patients with severe DE and allergy to preservatives, and recommended in patients with DE of moderate severity, blepharitis, in symptomatic patients, before filtering surgery to reduce preoperative inflammation, in those with moderate fluorescein staining of grade 2 on Oxford scheme, and reduced tear film break-up time.

scholarly journals Efficacy of Intense Pulsed Light Treatment in Patients with Sjögren’s Syndrome Associated with Meibomian Gland Dysfunction

2021 ◽  
Vol 62 (12) ◽  
pp. 1581-1591
Author(s):  
Ja Young Moon ◽  
Hyeon Jeong Yoon ◽  
Kyung-Chul Yoon
Keyword(s):  
Ocular Surface ◽  
Sjögren's Syndrome ◽  
Tear Film ◽  
Sjogren’S Syndrome ◽  
Meibomian Gland ◽  
Sjogren's Syndrome ◽  
Lipid Layer ◽  
Staining Score ◽  
Surface Staining ◽  
Sjögren‘S Syndrome

Purpose: To investigate the efficacy of intense pulsed light (IPL) treatment in patients with meibomian gland dysfunction (MGD) associated with Sjögren’s syndrome.Methods: This study included 43 patients with MGD and Sjögren’s syndrome. Patients received either IPL with meibomian gland expression (IPL/MGX) (n = 22) or MGX only (n = 21). Treatments were administered three times at a 3-week interval. Patients were followed up 6 weeks after the end of the treatment. Ocular Surface Disease Index (OSDI), tear film breakup time with fluorescein dye (FBUT), non-invasive tear breakup time, tear meniscus height (TMH), Schirmer test, SICCA ocular surface staining score, meibum quality score (MQS), and meibum expression score (MES) were evaluated at each visit. Meibomian gland dropouts (meiboscore) and tear film lipid layer grade were measured using keratography.Results: OSDI, FBUT, corneal surface staining score, MQS, meiboscore, and tear film lipid layer grade improved after IPL/MGX treatment (p < 0.05). In both treatment groups, MES significantly improved (p < 0.01 and p < 0.05 for IPL/MGX and MGX groups, respectively). The Schirmer test score, conjunctival surface staining score, and TMH after treatment were not significantly different between the groups. After treatment, the IPL/MGX group had significantly lower OSDI, FBUT, corneal staining score, MQS, and MES, but higher FBUT, compared with the MGX group (p < 0.05).Conclusions: IPL treatment effectively improved tear film, ocular surface parameters, meibomian gland function, and lipid layer grade in patients with Sjögren’s syndrome and MGD.

scholarly journals Contribution of Mucins towards the Physical Properties of the Tear Film: A Modern Update

2019 ◽  
Vol 20 (24) ◽  
pp. 6132 ◽  
Author(s):  
Georgi As. Georgiev ◽  
Petar Eftimov ◽  
Norihiko Yokoi
Keyword(s):  
Ocular Surface ◽  
Tear Film ◽  
The Novel ◽  
Mucin Secretion ◽  
Lipid Layer ◽  
The Impact ◽  
Ophthalmic Disease

Instability of the tear film (TF) protecting the ocular surface results in dry eye syndrome (DES), the most prevalent public health ophthalmic disease affecting the quality of life of 10 to 30% of the human population worldwide. Although the impact of the tear film lipid layer (TFLL) and of the aqueous tears (AT) to the TF stability is extensively studied, in contrast the contribution of the secretory mucins (SM) and of the membrane-associated mucins (MAM), i.e., one of the most abundant molecular classes in AT and in the corneal epithelium respectively, remains poorly defined. However, it is well known that in DES both types of mucins are quantitatively or qualitatively deficient. Numerous studies since the 1990s until now have proposed direct involvement of SM and MAM in the material properties (viscoelasticity, hydration, and protection of the ocular surface; synergistic cooperation with the rest of the TF layers; etc.) and stability of TF. These theories will be reviewed here in the context of the classical and modern in vitro and in vivo results that allow their reappraisal and in view of the novel mucin secretion enhancing pharmaceuticals, which have opened innovative routes for the therapy of DES.

Effect of changing from preserved prostaglandins to preservative-free tafluprost in patients with glaucoma on tear film thickness

2018 ◽  
Vol 28 (4) ◽  
pp. 385-392 ◽  
Author(s):  
Anton Hommer ◽  
Doreen Schmidl ◽  
Martina Kromus ◽  
Ahmed M Bata ◽  
Klemens Fondi ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Film Thickness ◽  
Dry Eye ◽  
Ocular Surface ◽  
Tear Film ◽  
Eye Drops ◽  
Life Score ◽  
Related Quality ◽  
Preservative Free

Purpose: Long-term glaucoma therapy with preservative-containing eye drops may impact ocular surface health. This study was performed to investigate whether a switch from preserved topical prostaglandin therapy to preservative-free tafluprost therapy improves precorneal tear film thickness in patients with glaucoma or ocular hypertension. Methods: A total of 30 patients who were under topical preservative-containing prostaglandin monotherapy for at least 6 months were included. Patients were then switched from preserved prostaglandin therapy to unpreserved tafluprost drops once daily. Tear film thickness was measured at baseline and 4 and 12 weeks after therapy change with an ultrahigh-resolution optical coherence tomography system. Furthermore, clinical measures of ocular surface disease were determined and symptoms were assessed using the Dry Eye–Related Quality-of-Life Score. Results: After switching to unpreserved tafluprost, tear film thickness significantly increased from 4.7 ± 0.5 to 5.0 ± 0.6 µm 4 weeks after therapy change and still tended to be increased after 12 weeks (4.8 ± 0.7 µm). Breakup time significantly increased from 5.1 ± 2.3 to 7.2 ± 3.4 s and to 10.1 ± 3.6 s after therapy change. In addition, a significant decrease in corneal staining score from 1.8 ± 0.7 to 1.4 ± 0.8 after 4 weeks and to 0.7 ± 0.7 after 12 weeks treatment was observed. Switching to preservative-free drops reduced Dry Eye–Related Quality-of-Life Score from 11.4 ± 11.0 to 5.7 ± 6.4 and to 4.7 ± 7.5. Conclusion: Our data show that switching to preservative-free tafluprost leads to an increase in tear film thickness, breakup time, and an improvement of Dry Eye–Related Quality-of-Life Score. Our results therefore indicate that a switch to unpreserved tafluprost is beneficial for ocular surface health in patients under long-term preserved prostaglandin eye drops.

Effects of tear film dynamics on quality of vision

2018 ◽  
Vol 102 (12) ◽  
pp. 1615-1620 ◽  
Author(s):  
Shizuka Koh ◽  
Cynthia I Tung ◽  
Yasushi Inoue ◽  
Vishal Jhanji
Keyword(s):  
Dry Eye ◽  
Current Knowledge ◽  
Tear Film ◽  
Optical Quality ◽  
Eye Drops ◽  
Wavefront Sensors ◽  
Wavefront Aberrations ◽  
Quality Of Vision ◽  
Definition Of

The precorneal tear film is maintained by blinking and exhibits different phases in the tear cycle. The tear film serves as the most anterior surface of the eye and plays an important role as a first refractive component of the eye. Alterations in tear film dynamics may cause both vision-related and ocular surface-related symptoms. Although the optical quality associated with the tear film dynamics previously received little attention, objective measurements of optical quality using wavefront sensors have enabled us to quantify optical aberrations induced by the tear film. This has provided an objective method for assessing reduced optical quality in dry eye; thus, visual disturbances were included in the definition of dry eye disease in the 2007 Dry Eye Workshop report. In addition, sequential measurements of wavefront aberrations have provided us with valuable insights into the dynamic optical changes associated with tear film dynamics. This review will focus on the current knowledge of the mechanisms of wavefront variations that are caused by different aspects of tear film dynamics: specifically, quality, quantity and properties of the tear film, demonstrating the respective effects of dry eye, epiphora and instillation of eye drops on the quality of vision.

scholarly journals Lipid composition of human meibum

2013 ◽  
Vol 72 (2) ◽  
Author(s):  
R. Schnetler ◽  
W. D. H. Gillan ◽  
G. Koorsen
Keyword(s):  
Lipid Analysis ◽  
Tear Film ◽  
Meibomian Gland ◽  
Cholesteryl Esters ◽  
Ocular Diseases ◽  
Healthy Individuals ◽  
Lipid Layer ◽  
Mucin Layer ◽  
Aqueous Layer ◽  
And Function

The structure and function of meibomian gland lipids in the tear film are highly complex. Evidence shows that the precorneal tear film consists of discrete layers: the inner mucin layer, the middle aqueous layer and the outer lipid layer. In this review we focus on the outer, biphasic lipid layer of the tear film which consists of a ‘thick’ outer, non-polar layer  and a ‘thin’ inner, polar layer. We discuss the main composition of the polar and non-polar lipids within meibum (wax esters, cholesteryl esters, mono-, di- and tri-acylglycerols, ceramides, phospholipids  et cetera). We address the composition of meibomian lipids in subjects suffering from various ocular diseases in comparison with the composition in healthy individuals. Further analysis is needed to determine whether a correlation exists between the etiology of various ocular diseases and the fluctuation on the lipids as well as to establish whether or not tear lipid analysis can be used as a diagnostic tool.

scholarly journals MODERN ASPECTS OF DEVELOPMENT AND TREATMENT OF DYSFUNCTIONS OF MEIBOMIAN GLANDS

2021 ◽  
Author(s):  
MEDEA GOBEJISHVILI ◽  
NINO NIKURADZE ◽  
LEVAN MIKELADZE
Keyword(s):  
Ocular Surface ◽  
Tear Film ◽  
Integrated Approach ◽  
Meibomian Gland ◽  
Meibomian Gland Dysfunction ◽  
Lipid Layer ◽  
Protective Properties ◽  
Meibomian Glands

The article analyzes the effectiveness of an integrated approach to the treatment of meibomian gland dysfunction, preparation of the eyelids using the copyright mechanical eye massager to evacuate the secretion of the meibomian glands. As a result, we get an improvement in the condition of the eyelids and the ocular surface due to the restoration of the lipid layer of the tear film, an increase in the protective properties of the tear film and an increase in the number of normally functioning meibomian glands.

New approaches to pharmacotherapy of allergic eye diseases

2015 ◽  
pp. 18-26
Author(s):  
Zoya Veselovska ◽  
Nataliia Veselovska
Keyword(s):  
Effective Means ◽  
Experimental Studies ◽  
Tear Film ◽  
Eye Diseases ◽  
Eye Drops ◽  
Lipid Layer ◽  
Ophthalmic Surgery ◽  
Promising Alternative ◽  
New Approaches ◽  
New Generation

The problem of studying the prеvalencе of allergic diseases of the eye and the search for new approaches and effective means to correct this condition does not lose its relevance. The presented data on the state of profound biochemical studies of the tear film in allergic conditions justify the expediency of the use of eye drops of a new generation. As a result of experimental studies on the effect on the lipid layer ectoine was discovered the mechanism of its therapeutic action. This paper presents compelling evidence that new eye drops based on natural molecules ectoine which are able to restore and maintain the functional state of the lipid layer of the tear film in the pharmacotherapy of аllergic diseases of anterior surface of the eye. The analyzes of multiple experimental data revealed the clear evidence of mechanisms of action on the eye and the first clinical experience with a new pharmacological agent testifies to its strong anti-inflammatory and regenerative effect due to the stabilization of the lipid layer of the tear film and the protection of the front surface of the eye tissue from the hyperosmolarity. It was confirmed by the subjective and objective reducing eye irritation and dryness in reducing itching and burning from the conjunctiva, to improve the moisture level of the surface of the eye, to reduce discomfort of the eyes. The drug can be used in children older than 2 years and adults, when wearing contact lenses, ophthalmic surgery and after an eye injury. Based on this, it can be conclude that the appearance in the arsenal of new-generation antiallergic eye drops (EYE-t) with sufficient efficacy and safety profile can be regarded as a promising alternative approach to the treatment of allergic and inflammatory eye diseases.

scholarly journals Cationic Thiolated Poly(aspartamide) Polymer as a Potential Excipient for Artificial Tear Formulations

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Mária Budai-Szűcs ◽  
Gabriella Horvát ◽  
Barnabás Áron Szilágyi ◽  
Benjámin Gyarmati ◽  
András Szilágyi ◽  
...  
Keyword(s):  
Dry Eye ◽  
Tear Film ◽  
Dry Eye Disease ◽  
Eye Disease ◽  
Eye Drops ◽  
Thiol Groups ◽  
Physiological Properties ◽  
Disulphide Bond Formation ◽  
Polymer Bearing

Dry eye disease is a relatively common ocular problem, which causes eye discomfort and visual disorders leading to a decrease in the quality of life. The aim of this study was to find a possible excipient for eye drop formulations, which is able to stabilize the tear film. A cationic thiolated polyaspartamide polymer, poly[(N-mercaptoethylaspartamide)-co-(N-(N′,N′-dimethylaminoethyl)aspartamide)] (ThioPASP-DME), was used as a potential vehicle. Besides satisfying the basic requirements, the chemical structure of ThioPASP-DME is similar to those of ocular mucins as it is a protein-like polymer bearing a considerable number of thiol groups. The solution of the polymer is therefore able to mimic the physiological properties of the mucins and it can interact with the mucus layer via disulphide bond formation. The resultant mucoadhesion provides a prolonged residence time and ensures protective effect for the corneal/conjunctival epithelium. ThioPASP-DME also has an antioxidant effect due to the presence of the thiol groups. The applicability of ThioPASP-DME as a potential excipient in eye drops was determined by means of ocular compatibility tests and through examinations of the interactions with the mucosal surface. The results indicate that ThioPASP-DME can serve as a potential eye drop excipient for the therapy of dry eye disease.

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