Ophthalmic Viscoelastic Device
Ophthalmic Viscoelastic Device - Related Videos
06:59
In Vivo Evaluation of the Mechanical and Viscoelastic Properties of the Rat Tongue
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2017
We describe a surgical procedure in an anesthetized rat model for determining the muscle tone and viscoelastic properties of the tongue. The procedure involves specific stimulation of the hypoglossal nerves and application of passive Lissajous force/deformation curves to the muscle.
01:23
Ophthalmic Drug Delivery Systems
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2026
Ophthalmic drug delivery faces major limitations due to poor absorption across the corneal membrane. This process is primarily driven by diffusion and is influenced by two main factors: the physicochemical properties of the drug and tear drainage. Most ophthalmic drugs, such as pilocarpine, epinephrine, atropine, and local anesthetics, are weak bases. They are typically formulated at an acidic pH to enhance chemical stability. However, this leads to high ionization, reducing their ability to...
03:54
Magnetic Resonance Elastography for Assessing Viscoelastic Properties
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2025
Source: Feng, Y., et al. Viscoelastic Characterization of Soft Tissue-Mimicking Gelatin Phantoms using Indentation and Magnetic Resonance Elastography. J. Vis. Exp. (2022) This video demonstrates the method of magnetic resonance elastography (MRE) for assessing tissue viscoelastic properties by analyzing shear wave propagation through a gelatin phantom, mimicking brain tissue. The process involves generating and capturing shear waves with magnetic resonance imaging or MRI and analyzing wave...
08:29
Thermal Measurement Techniques in Analytical Microfluidic Devices
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Cited by 6 •
2015
Here, we present three protocols for thermal measurements in microfluidic devices.
10:28
Experimental Measurement of Settling Velocity of Spherical Particles in Unconfined and Confined Surfactant-based Shear Thinning Viscoelastic Fluids
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Cited by 15 •
2014
This paper demonstrates the experimental procedure to measure terminal settling velocities of spherical particles in surfactant-based shear thinning viscoelastic fluids. Fluids over a wide range of rheological properties are prepared and settling velocities are measured for a range of particle sizes in unbounded fluids and fluids between parallel walls.
FAQs
Viscosity controls how an OVD behaves as instruments move through the eye. Higher viscosity contributes to maintaining space and supporting anterior chamber stability, while surface-coating properties help limit direct mechanical stress on delicate tissues. These effects matter because surgical access must remain controlled while the surgeon manipulates structures, so viscosity is considered alongside cohesiveness and dispersiveness.
Cohesiveness and dispersiveness describe different selection profiles that complement viscosity. Considering them together helps clinicians match an OVD to competing surgical needs: maintaining a stable anterior chamber, coating and protecting delicate tissues, and permitting controlled access for instruments. The choice therefore affects the balance among chamber support, tissue protection, and the practical need for postoperative removal.
Protection of the corneal endothelium depends on reducing the mechanical burden created during intraocular manipulation. An OVD contributes through its high viscosity and surface-coating properties, which help shield delicate tissue as instruments move. This is especially relevant in cataract surgery, where controlled access and tissue protection must be maintained while the procedure proceeds.
During cataract extraction, the device helps create and preserve the working space of the anterior chamber while instruments are used. Its stabilizing and tissue-protective effects support controlled surgical access rather than merely filling the chamber. This role continues into intraocular lens implantation, when maintaining suitable space and protecting delicate structures facilitate controlled lens placement.
Selection must balance the material’s intraoperative benefits with the practical need for postoperative removal. Viscosity, cohesiveness, and dispersiveness all contribute to how clinicians weigh chamber stability, tissue coating, and controlled access against removal considerations. This prevents selection from focusing on a single property and links the material choice to both surgical performance and postoperative management.
OVDs are especially relevant to cataract extraction and intraocular lens implantation because these procedures require controlled access, chamber stability, tissue protection, and support for lens placement. Their contribution can be evaluated against those surgical goals, together with how readily the selected material can be removed afterward. This connects material properties with intraoperative performance and postoperative management.