On the mechanics of a detaching retina

Bottega, W.J.; Bishay, Peter L.; Prenner, Jonathan L.; Fine, Howard F

doi:10.1093/imammb/dqs024

Cited by 14 publications

(3 citation statements)

References 35 publications

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“…The effective pressure increases considerably with decreasing the distance between the closest faces of the MAE and magnetic band exceeding 1000 Pa at d=0.7 mm. This effective pressure is enough for keeping retina reattached since retina is 250 μm thick easy deformable tissue [60][61][62][63][64][65][66].…”

Section: Pressure In Mae-multiple Magnet Systemsmentioning

confidence: 99%

Magnetoactive elastomer as an element of a magnetic retina fixator

Makarova

Nadzharyan

Alekhina

et al. 2017

Smart Mater. Struct.

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We explore the possibility of creating an effective retinal fixator on the basis of magnetoactive elastomers (MAEs) and systems of permanent magnets. MAEs consist of silicone elastomer matrix with embedded magnetic iron microparticles. We study theoretically and experimentally magnetic forces acting between MAE samples and permanent magnets in various configurations. The theoretical model is based around classical magnetostatics and Maxwell equations with different parameters accounting for peculiarities of the material and the setup. Approximation of the experimentally measured magnetization curves for MAE samples was used to find input parameters for the theoretical model. To test the model, we conducted a series of experimental measurements of magnetic forces accompanied by model predictions for the system of one cylindrical magnet and a cuboid MAE sample. Calculated dependences of the average pressure arising from magnetic interactions on the distance between the closest faces of MAE samples and a permanent magnet are in a good agreement with the experimental data. The proof on concept for smaller magnetic systems required for eye surgery includes data for 10 magnets configuration and a thin MAE band. This research demonstrates high prospects of using MAE as an element of a magnetic fixator for treatment of complicated retinal detachments.

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Section: Pressure In Mae-multiple Magnet Systemsmentioning

confidence: 99%

Magnetoactive elastomer as an element of a magnetic retina fixator

Makarova

Nadzharyan

Alekhina

et al. 2017

Smart Mater. Struct.

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“…Detachment of the retina from the RPE/choroid is influenced by several physical forces: retinal tensile force, retinal adhesive force, and intraocular fluid flow [23,24]. Figure 1 illustrates several physical forces occurring in normal and detached retinas.…”

Section: Mechanical Forces On the Retina Occurring In Retinal Detachmentmentioning

confidence: 99%

Concept and application of relaxing radial retinectomy for retinal detachment with advanced proliferative vitreo-retinopathy

et al. 2020

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Purpose To revisit the concept of retinectomy and the theory of mechanical forces on the retina occurring in rhegmatogenous retinal detachment (RRD) and to describe the potential application of radial retinectomy in RRD with advanced proliferative vitreoretinopathy (PVR). Methods A literature search was performed to identify all English language articles reporting the use of retinectomy for the management of RRD with PVR. We reviewed the theoretical background of mechanical forces occurring in RRD. Results Detachment of the retina from the retinal pigment epithelium (RPE)/choroid is influenced by disequilibrium of several physical forces: tangential forces on the epiretinal membrane $$\left( {T_{1} } \right)$$ T 1 and radial traction on the retina $$F_{R}$$ F R exceeding the retinal adhesion force to the RPE $$\left( {T_{1} \;\text{ + }F_{R} \;\text{ > }\;F_{A} } \right)\,\,$$ T 1 + F R > F A . PVR may exaggerate the amounts of tangential and radial forces ($$\left( {T_{1} } \right)$$ T 1 and $$F_{R}$$ F R ) that pull the retina off. Relaxing radial retinectomy, by the nature of its cutting pattern, may theoretically decrease the amounts of both forces, therefore restoring the equilibrium between tensile and adhesive forces on the retinal surface $$\left( {T_{1} \;\text{ + }F_{R} \;\text{ = }\;F_{A} } \right)\,\,$$ T 1 + F R = F A . Conclusion Relaxing radial retinectomy may potentially be applied in RRD with advanced PVR but has rarely been reported to date. Future studies are needed to evaluate its outcomes and long-term complications.

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“…Such a method has been used in various applications, such as cardiac valves [8] and animal locomotion [9], but this is the first time, to the authors knowledge, it has been used in the context of retinal detachment modelling. Previous works regarding the retina include calculating the shear stress on the retinal surface [10,11,12,13,14,15], gas diffusion in the vitreous cavity [16], silicone oil usage [17,18], retinal tractions [19] and peeling of membranes from the retinal surface [17,20], just to mention a few. In order to study the tendency of the retina to further detach from the underlying choroid, due to the combined actions of the forces and torque at the attachment point(s) arising from the interaction between the detached retina and the surrounding fluid, we borrow a simple model from geotechnics of a structure on an elastic foundation [21].…”

Section: Introductionmentioning

confidence: 99%