This paper investigates the effect of surfactants during tear film deposition and subsequent thinning. The surfactants occur naturally on the surface of the tear film in the form of a lipid layer. A lubrication model is developed that describes lipid spreading and film height evolution. It is shown that lipids may play an important role in drawing the tear film up the cornea during the opening phase of the blink. Further, nonuniform distributions of lipids may lead to a rapid thinning of the tear film behind the advancing lipid front (shock). Experiments using a fluorescein dye technique and using a tearscope were undertaken in order to visualise the motion of the lipid layer and any associated shocks immediately after a blink. It is found that the lipid layer continues to spread upwards on the cornea after the opening phase of the blink, in agreement with the model. Using the experimental data, lipid particles were tracked in order to determine the surface velocity and these results are compared to the model predictions.
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http://dx.doi.org/10.1007/s11538-006-9105-9 | DOI Listing |
Biomed Pharmacother
January 2025
Department of Stem Cell and Regenerative Biotechnology, School of Advanced Biotechnology, Molecular & Cellular Reprogramming Center, Institute of Advanced Regenerative Science, and Institute of Health, Aging & Society, Konkuk University, 120 Neungdong-ro Gwangjin-gu, Seoul 05029, Republic of Korea; R&D Team, StemExOne Co., Ltd., Seoul, Republic of Korea. Electronic address:
The human lacrimal gland (LG), located above the outer orbital region within the frontal bone socket, is essential in maintaining eye surface health and lubrication. It is firmly anchored to the orbital periosteum by the connective tissue, and it is vital for protecting and lubricating the eye by secreting lacrimal fluid. Disruption in the production, composition, or secretion of lacrimal fluid can lead to dry eye syndrome, a condition characterized by ocular discomfort and potential eye surface damage.
View Article and Find Full Text PDFClin Exp Optom
January 2025
Department of Ophthalmology, Giresun University, Giresun, Turkey.
Clinical Relevance: The prevalence of male androgenetic alopecia is increasing worldwide. Evaluation of dry eye parameters and meibomian glands of male androgenetic alopecia patients may help to better understand the effect of this disease on dry eye and to provide appropriate treatment for these patients.
Background: The aim of this work is to evaluate the relationship between male androgenetic alopecia, dry eye, and meibomian gland function.
Pharmaceuticals (Basel)
January 2025
Department of Ophthalmology, Chonnam National University Medical School and Hospital, Gwangju 61469, Republic of Korea.
: This study aimed to evaluate the therapeutic effects of combined 5% lifitegrast (LF) and tocopherol (TCP) eye drops in a murine experimental dry eye (EDE) model. Female C57BL/6 were divided into seven groups: untreated controls, EDE control, EDE + 0.05% cyclosporin A (CsA), EDE + tocopherol (TCP), EDE + 5% LF, EDE + 5% LF + TCP (once daily), and EDE + 5% LF + TCP (twice daily).
View Article and Find Full Text PDFJ Clin Med
January 2025
GI-2092-Optometry, Departamento de Física Aplicada (Área de Optometría), Universidade de Santiago de Compostela, Campus Vida s/n, 15701 Santiago de Compostela, Spain.
: The aim of the present study was to establish a cut-off value of the Lipid Layer Pattern (LLP) between participants with different subtypes of Dry Eye Disease (DED) including Deficient Dry Eye (ADDE), Evaporative Dry Eye (EDE), and Mixed Dry Eye (MDE). : 240 participants diagnosed with DED according to the Tear Film and Ocular Surface Society in the Dry Eye Workshop II guidelines were included in the study. Tear Meniscus Height (TMH) using the Tearscope illumination and Meibomian Gland Loss Area (MGLA) using the Keratograph 5M were assessed to categorize the participants into an ADDE group, EDE group, or MDE group.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
Department of Ophthalmology, Penn State University, Hershey, PA 17033, USA.
Extracellular vesicles (EVs) are lipid bilayer particles released by virtually all cells, with prominent roles in both physiological and pathological processes. The size, number, and molecular composition of released EVs correlate to the cells of origin, modulated by the cell's environment and pathologic state. The proteins, DNA, RNA, and protein cargo carried by EVs are protected by degradation, with a prominent role in targeted intercellular signaling.
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