The Physiology of Tear Film

Mapping Intimacies ◽

10.5772/intechopen.98945 ◽

2021 ◽

Author(s):

Abraham Kayal

Keyword(s):

Thin Layer ◽

Dry Eye ◽

Layered Structure ◽

Tear Film ◽

Dry Eye Syndrome ◽

Conjunctival Epithelium ◽

Optical Medium ◽

Homeostatic Process ◽

Structure Lipid ◽

Immunological Factors

The precorneal tear film is a thin layer, about 2–5.5 μm thick, which overlays the corneal and conjunctival epithelium. It functions to lubricate and protect the corneal and eyelid interface from environmental and immunological factors as well as provide an optical medium. The tear film is depicted as a three-layered structure: lipid, aqueous, and mucous layers. Within each layer possesses a different composition which dictates its function. In common between the three layers are their homeostatic process of evaporation and drainage. Any dysfunction in either of the layers can result in Dry Eye Syndrome (DES). The composition, regulation, and pathology of tear film will be discussed in this chapter.

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Corneal topography and classical test in the diagnosis of dry eye syndrome in patients with myopia and myopic astigmatism before keratorefractive surgery

Modern technologies in ophtalmology ◽

10.25276/2312-4911-2021-1-39-43 ◽

2021 ◽

pp. 39-43

Author(s):

Y.V. Kutuzova ◽

◽

I.V. Dutchin ◽

E.L. Sorokin ◽

◽

...

Keyword(s):

Dry Eye ◽

Tear Film ◽

Risk Groups ◽

Corneal Topography ◽

Dry Eye Syndrome ◽

Film Rupture ◽

Keratorefractive Surgery ◽

The Stability ◽

High Degree ◽

Myopic Astigmatism

Purpose.To conduct a comparative analysis of the effectiveness of assessing the stability of the tear film using corneotopography and the classic Norn test in patients with myopia and myopic astigmatism before keratorefractive surgery. Material and methods. The study included 26 patients planned for keratorefractive surgery for myopia and myopic astigmatism, aged 18 to 47 years. 7 people there was a mild degree of myopia, in 14 people – medium degree, in 5 people – high degree. The average degree of corneal astigmatism was 2.25 diopters. The stability of the pre-corneal tear film was assessed using computed keratotopography and Norn's test – the tear film rupture time (TFRT) was deter- mined. A standard questionnaire was also used to assess the severity of symptoms of dry eye syndrome. A comparison was made of the indicators of the stability of the tear film obtained by the methods of corneotopography and the Norn's test, with their subsequent comparison with the data of the questionnaire. Results. In 17 patients (65.4%), the TFRT index corresponded to the age norm. In the remaining 9 people (34.6%), indicators of stability of the tear film were reduced both by corneotopography (12±4 sec) and by Norn's test (13.5±4.5 sec), and there were also subjective signs of dry eye syndrome according to data questionnaire. The data turned out to be comparable. Conclusions. 1. Among the total population of patients, 34.6% were persons with impaired tear film stability and subjective manifestations of dry eye syndrome. 2. Assessment of the stability of the tear film, determined using the method of corneal topography, showed a high degree of comparability with the results of Norn's test. A significant advantage of the keratotopography method is its non-invasiveness. 3. It is necessary to pay attention to the condition of the ocular surface and identify risk groups to avoid chronicity or aggravation of existing disorders. Key words: dry eye syndrome, tear film, keratotopography, Norn's test.

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«Dry eye» syndrome and primary glaucoma: possibilities of treatment

Reflection ◽

10.25276/2686-6986-2020-1-42-44 ◽

2020 ◽

Vol 10 (1) ◽

pp. 42-44

Author(s):

L.I. Solovyova ◽

◽

T.V. Gavrilova ◽

F.G. Mugumova ◽

◽

...

Keyword(s):

Dry Eye ◽

Open Angle Glaucoma ◽

Tear Film ◽

Dry Eye Syndrome ◽

Rupture Time ◽

Eye Drops ◽

Film Rupture ◽

Good Tolerability ◽

Primary Glaucoma ◽

The Stability

The article presents the results of Ocuhyl C using in the treatment of «dry eye syndrome» (DES) in 47 eyes of 26 patients with different stages of compensated primary open-angle glaucoma. Experience of instillation of hypotensive eye drops with preservatives was from 1 year to 35 years. Assessment of subjective signs of DES was performed by questioning. Functional tests were performed (for the stability of the precorneal tear film –Norn test, for the level of total tear production –Shirmer test). Examinations were carried out at the first examination before prescribing the drug, then after 4 and 8 weeks of its use. All the patients noted good tolerability of the drug, no side effects. Indicators characterizing the feeling of a foreign body, dryness and redness of the eyes have significantly decreased. Precorneal tear film rupture time has significantly increased. Ocuhyl C can be recommended for clinical use. Key words: primary glaucoma; “dry eye” syndrome; tear forming; tear film rupture time; Ocuhyl C.

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PENGARUH EMISI DEBU SEMEN TERHADAP STATUS TEAR FILM MASYARAKAT DI SEKITAR PABRIK PT. SEMEN PADANG

Jurnal Kesehatan Andalas ◽

10.25077/jka.v6i3.753 ◽

2018 ◽

Vol 6 (3) ◽

pp. 654

Author(s):

Muhammad Syauqie ◽

Ardizal Rahman ◽

Getry Sukmawati

Keyword(s):

Dry Eye ◽

Tear Film ◽

Cross Sectional Study ◽

Dry Eye Syndrome ◽

Sectional Study ◽

Cross Sectional ◽

Break Up

Permukaan okular rentan terhadap efek iritatif dari debu semen tersebut karena epitel konyungtiva dan kornea hanya dilapisi oleh lapisan tipis tear film. Paparan debu semen jangka panjang menyebabkan terjadinya inflamasi subklinis kronik yang dapat mempengaruhi transdiferensiasi epitel konyungtiva dan densitas sel goblet yang kemudian dapat menyebabkan timbulnya gejala dry eye syndrome. Tujuan penelitian ini adalah menilai status tear film pada masyarakat yang terpapar emisi debu semen dibandingkan dengan masyarakat yang tidak terpapar. Penelitian ini berupa analytic cross sectional study pada dua populasi yaitu kelompok terpapar dan tidak terpapar emisi debu pabrik semen. Semua sampel penelitian dari dua populasi menjalani pemeriksaan pH tear film, Schirmer, Ferning dan Tear Break Up Time (TBUT). Hasil studi mendapatkan peningkatan nilai pH tear film yang bermakna pada penduduk di kelompok terpapar dengan p=0.001. Terdapat juga penurunan kualitas Ferning yang bermakna pada penduduk di kelompok terpapar yang didominasi tipe III dengan p=0.005 dan 0.029. Sedangkan hasil pemeriksaan Schirmer dan TBUT masih dalam batas normal dan tidak terdapat perbedaan yang bermakna antara kedua kelompok. Simpulan studi ini ialah erdapat peningkatan rerata nilai pH tear film dan penurunan kualitas lapisan musin tear film yang bermakna pada masyarakat yang terpapar emisi debu semen namun tidak didapatkan peningkatan kejadian dry eye yang bermakna.

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Gpr125 identifies myoepithelial progenitors at tips of lacrimal ducts and is essential for tear film

10.1101/2020.09.15.296749 ◽

2020 ◽

Author(s):

Elena Spina ◽

Rebecca Handlin ◽

Julia Simundza ◽

Angela Incassati ◽

Muneeb Faiq ◽

...

Keyword(s):

Dry Eye ◽

Essential Role ◽

Tear Film ◽

Lineage Tracing ◽

Dry Eye Syndrome ◽

Planar Polarity ◽

Inflammatory Infiltration ◽

Discrete Population ◽

Signaling Domains ◽

G Protein Coupled

AbstractGpr125, encoded by Adgra3, is an orphan adhesion G-protein coupled receptor (aGPCR) implicated in modulating Wnt signaling and planar polarity. Here we establish both physiological and pathological roles for Gpr125. We show that mice lacking Gpr125 or its signaling domains display an ocular phenotype with many hallmarks of human dry eye syndrome. These include squinting, abnormal lacrimation, mucus accumulation, swollen eyelids and inflammatory infiltration of lacrimal and meibomian glands. Utilizing a Gpr125-β-gal reporter and scRNAseq, we identify Gpr125 expression in a discrete population of cells located at the tips of migrating embryonic lacrimal ducts. By lineage tracing we show these cells function as progenitors of the adult lacrimal myoepithelium. Beyond defining an essential role for Gpr125 in tear film and identifying its utility as a marker of lacrimal progenitors, this study implicates Gpr125 in the etiology of blepharitis and dry eye syndrome, and defines novel animal models of these common maladies.

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CLINICAL AND HISTOPATHOLOGICAL FEATURES OF SCOPOLAMINE HYDROBROMIDE INDUCED DRY EYE SYNDROME IN SPRAGUE-DAWLEY RATS

Taiwan Veterinary Journal ◽

10.1142/s1682648520500134 ◽

2021 ◽

pp. 1-8

Author(s):

Sze-Min Chan ◽

Hui-Wen Chang ◽

Pei-Shiue Tsai ◽

Chian-Ren Jeng ◽

Hao Lee ◽

...

Keyword(s):

Dry Eye ◽

Histopathological Examination ◽

Tear Film ◽

Dry Eye Syndrome ◽

Therapeutic Interventions ◽

Sprague Dawley ◽

Corneal Surface ◽

Fluorescein Staining ◽

Scopolamine Hydrobromide ◽

Volume Assessment

Dry eye syndrome (DES), is one of the most common and irritating ocular diseases in humans and animals due to deficits in quantities or/and quality of tear film. In this study, a rat model of experimental DES has been developed using the cholinergic inhibitor, scopolamine hydrobromide (SCOP), at the dose of 25[Formula: see text]mg/rat/day via subcutaneous injection, for a consecutive 21 days without low humidity environment. Clinical ophthalmic evaluations were performed by tear volume assessment using endodontic paper point, slit-lamp biomicroscope, and fluorescein staining at day 0, 7, 14, and 21 post-inductions. The results of ophthalmic examination showed that rats with SCOP treatment reduced about 40% of tear secretion. Half of the SCOP-treated rats exhibited diffuse corneal fluorescein staining involving 80% of the corneal surface, minimal keratoconjunctivitis, roughened corneal surface and thin corneal epithelium under histopathological examination. About 30% of the rats showed variable infiltration of lymphocytes in between the tubular acinar glands. This animal model with significant reduction of tear production and diffuse corneal fluorescein staining in rats could be used for the preclinical assessment of therapeutic interventions.

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Dry eye syndrome in patients with gout

POINT OF VIEW EAST – WEST ◽

10.25276/2410-1257-2021-4-6-11 ◽

2021 ◽

pp. 6-11

Author(s):

K.N. Odinaeva ◽

◽

N.S. Al Khateeb ◽

M.A. Frolov ◽

◽

...

Keyword(s):

Uric Acid ◽

Correlation Coefficient ◽

Dry Eye ◽

Strong Correlation ◽

Strong Dependence ◽

Tear Film ◽

Dry Eye Syndrome ◽

Film Rupture ◽

High Tendency ◽

Tear Production

Purpose. To determine and study the features of the development of dry eye syndrome (DES) in gout, depending on urate-lowering therapy, the duration of the gout disease and the concentration of uric acid in the tear. Material and methods. The study involved 149 male patients (261 eyes) aged 35 to 75 years (mean age 60.63 ± 11.00 years). Among them, 110 people (202 eyes) with an established diagnosis: "Cataract with concomitant gout disease" and 39 people (59 eyes) with cataracts without clinical and laboratory signs of gout. All patients underwent both standard ophthalmological examinations and special ones. The concentration of uric acid in tears was determined by high performance liquid chromatography (HPLC). The diagnosis of gout was confirmed according to the criteria recommended by ACR / EULAR (2016). Results. In patients with gout who do not take a urate-lowering drug, DES occurs more often (82.1%) than in patients without gout (23.1%). With an increase in the concentration of uric acid in the tear, there is a high tendency to a shortening of the tear film rupture time (strong correlation coefficient r=-0.51, p<0.001) and to a decrease in tear production (Schirmer I test) (strong correlation coefficient r=-0.59, p<0.001). Conclusion. The data obtained indicate clear changes in the functional parameters of total tear production (Schirmer I's test) and the stability of the pre-corneal tear film (Norn's test) in patients with gout. This can be considered as a fact of the predisposition of this category of patients to the development of DES. A strong dependence of changes in tear production and HRVP on the concentration of uric acid in the tear was established. There is an obvious need for additional examination of this category of patients and an adequate choice of therapy, as well as the timely appointment of "artificial tear" drugs. Key words: dry eye syndrome, uric acid, gout.

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Disease Update on Human Tear Proteome

European Ophthalmic Review ◽

10.17925/eor.2013.07.01.36 ◽

2013 ◽

Vol 07 (01) ◽

pp. 36 ◽

Cited By ~ 1

Author(s):

Piera Versura ◽

Emilio C Campos ◽

◽

Keyword(s):

Chemical Composition ◽

Thin Layer ◽

Clinical Application ◽

Newtonian Fluid ◽

Dry Eye ◽

Proteomic Analysis ◽

Complex Structure ◽

Tear Film ◽

Potential Clinical Application ◽

Recent Advances

Tear film is a thin layer of non-newtonian fluid covering and protecting cornea and conjunctiva epithelia. The multifaced functions of tears are reflected by their complex structure and advances in proteomics/metabolomics/lipidomics technologies have greatly deepened the knowledge of the chemical composition of tears. The purpose of this article is to survey recent advances in proteomic analysis of human tears and to summarise the most relevant proteins proposed as biomarkers in dry eye. Besides, the potential clinical application of these biomarkers is discussed.

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