Dynamics of a Gel-Based Artificial Tear Film with an Emphasis on Dry Disease Treatment Applications

Mehdaoui, Hamza; Abderrahmane, Hamid Ait; Loubens, Clément de; Bouda, Faïçal Nait; Hamani, Sofiane

doi:10.3390/gels7040215

Cited by 5 publications

(3 citation statements)

References 38 publications

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“…Consequently, RDA maintains the structure and viscoelastic properties of the MGS duplex multilayer, which are believed to be crucial for the TFLL's ability to restore and maintain the tear film at the ocular surface in vivo during and between blinks [4,10,31]. The formulation additionally endeavors to enhance the secretory-mucin-rich gel layer of human tears by incorporating polyvinylpyrrolidone, a polymer that is believed to augment the tear film's shear thinning properties [35][36][37][38][39][40]. These properties are crucial for the lubricating action of TF during blinking, as well as for its tensile strength when at interblink [41][42][43][44].…”

Section: Discussionmentioning

confidence: 99%

Surface Chemistry Study of Normal and Diseased Human Meibum Films Prior to and after Supplementation with Tear Mimetic Eyedrop Formulation

Eftimov,

Yokoi,

Tsuji

et al. 2024

Applied Sciences

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Ophthalmic nanoemulsions that can treat the deficiencies of meibum (MGS) in Meibomian gland disease and restore its functionality in the tear film are greatly sought. The Rohto Dry Aid (RDA) formulation employs TEARSHIELD TECHNOLOGYTM, which uses a multicomponent oil phase of polar and non-polar lipid-like molecules selected to mimic the profiles of healthy meibum. Thus, the interactions of RDA with “diseased” Meibomian (dMGS) films merit deeper analysis, as these interactions might offer important clues for both the development of new ocular formulations and the processes behind the therapeutic action of the nanoemulsions. Pseudobinary dMGS/RDA films were spread at the air–water surface of the Langmuir trough. Surface pressure-area isocycles and stress relaxations were used to access the layer’s response to blink-like cycling and dilatational viscoelasticity, respectively, while film morphology was recorded via Brewster angle microscopy. It was found that RDA is able to reverse the brittleness and to restore the stability of “diseased” MGS films and thus to revert the layer’s properties to the functionality of healthy Meibomian lipids. Therefore, in order to effectively treat dry eyes with MGS-oriented therapy, ophthalmic nanoemulsions warrant more research.

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Section: Discussionmentioning

confidence: 99%

Surface Chemistry Study of Normal and Diseased Human Meibum Films Prior to and after Supplementation with Tear Mimetic Eyedrop Formulation

Eftimov,

Yokoi,

Tsuji

et al. 2024

Applied Sciences

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“…Later models have included the effect of polar lipids via the Marangoni effect; [59][60][61][62] partial blinks; 63,64 a non-polar LL; 52,65 the curvature of the ocular surface 66 ; and non-Newtonian effects. [67][68][69] Models for flow over the (2D) exposed ocular surface have been developed. [70][71][72][73][74][75] The 2D models capture a number of aspects of the overall flows, osmolarity, and FL imaging.…”

Section: Mathematical Modelsmentioning

confidence: 99%

Fitting ODE models of tear film breakup

Driscoll,

Braun,

Luke

et al. 2023

MAIO

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Purpose: Several elements are developed to quantitatively determine the contribution of different physical and chemical effects to tear breakup (TBU) in subjects with no self-reported history of dry eye (DED) or other ocular surface disease. Fluorescence (FL) imaging is employed to visualize the tear film (TF) and to determine TF thinning and potential TBU. Methods: An automated system using a convolutional neural network that was trained and tested on more than 50,000 images from FL imaging experiments was deployed. The trained system could identify multiple TBU instances in each trial. Once identified, extracted FL intensity data was fit by mathematical models that included tangential flow along the eye, evaporation, osmosis, and FL intensity of emission from the TF. The mathematical models consisted of systems of ordinary differential equations for the aqueous layer thickness, osmolarity, and the FL concentration; they are a local approximation to TF thinning and/or TBU dynamics. FL intensity was computed using the resulting thickness and FL concentration. Optimizing the fit of the models to the FL intensity data determined the mechanism(s) driving each instance of TBU and produced an estimate of the osmolarity within TBU. Results: Initial estimates for FL concentration and initial TF thickness agree well with prior results. Fits were produced for N = 467 instances of potential TBU from 15 non-DED subjects. The results showed a distribution of causes of TBU in these healthy subjects, as reflected by estimated flow and evaporation rates, which appear to agree well with previously published data. Final osmolarity depended strongly on the TBU mechanism, generally increasing with evaporation rate but complicated by the dependence on flow. Conclusion: The method has the potential to classify TBU instances based on the mechanism and dynamics, and to estimate the final osmolarity at the TBU locus. The results suggest that it might be possible to classify individual subjects and provide a baseline for comparison and potential classification of DED subjects.

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“…Other than robust gels for biomedical applications, low viscous gels were essential to ophthalmic diseases. The design of these gels and their mechanical properties were discussed in detail [ 6 , 7 ]. Meanwhile, Huang et al controlled the mechanical properties of poly(methyl methacrylate) hydrogels via dynamical physical crosslinks from pillar[5]arene-based host–guest interactions [ 8 ].…”

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confidence: 99%