Make the Right Choice for Your Patients
Your choice of OVD can impact your success in the OR—and your patients' outcomes afterward.
At Alcon, we think that better information leads to better choices. This section is dedicated to a deeper understanding of OVDs—to help you give the gift of better vision, seamlessly.
Making Phacoemulsification Possible
OVDs protect the cornea, iris, and other internal structures during phaco. They create a stable yet flexible environment for surgery. They enable a range of surgical techniques. But how do they work? Find out how, and improve your results.
What are OVDs?
OVD is short for Ophthalmic Viscosurgical Device.1 The term refers to a set of components originally designed to protect internal eye tissues during surgery. In addition to coating tissues, OVDs:
- Create a protective barrier
- Help reduce free radicals
- Create and maintain space within the anterior chamber
- Aid in manipulation of tissues during surgery
- Coat surgical instruments and IOLs
Ophthalmic surgeons employ OVDs in a variety of procedures, including cataract removal, keratoplasty, glaucoma surgeries, retinal procedures, and ocular trauma treatments.
Since the first OVD was introduced in 1980, viscoelastic design has improved by leaps and bounds. OVDs are created with several key ingredients, including:
A gel-like aminoglycan found in tissues, the synovial fluid of the joints and the vitreous humor of the eyes. Hyaluronic acid is used in most OVDs to help lubricate and provide space.
Short for Hydroxypropyl Methylcellulose, HPMC is comprised of plant-based components and was one of the first OVDs used to extend the effectiveness of lubricants in the eye. HPMC is not widely used, since its components are not bioavailable within the human body.
A type of polysaccharide found in blood vessels, bone tissue, cartilage, and the cornea. Chondroitin Sulfate:
- Hyaluronic Acid
- Chondroitin Sulfate
- - Stabilizes the cell membrane
- - Coats the corneal endothelium
- - Naturally mitigates free radicals
- - Is a Newtonian material, meaning it does not lose viscosity under stress
These traits make it better at protecting the corneal endothelium. Only DisCoVisc® OVD and DuoVisc® Viscoelastic System contain Chondroitin Sulfate.
Types of OVDs
OVD classifications are constantly evolving. The 3 best known categories are:
A high-density, high-viscosity product used to provide space within the anterior chamber and manipulate intraocular tissues. The viscosity of these OVDs changes rapidly under stress (called pseudoplasticity). Healon* OVD by AMO and ProVisc® OVD, by Alcon, are cohesive OVDs.
A low-viscosity product used to coat and protect cellular structures while maintaining space and easing mechanical operation. Effective dispersive OVDs coat the endothelium and resist removal during aspiration. Dispersives are often used in concert with cohesives to create a usable surgical space. VISCOAT® OVD, by Alcon, is the classic example of a dispersive OVD.
A product with relatively high viscosity that offers space maintenance, protection (via retention) during phaco and yet is also relatively easy to aspirate. Viscous dispersives are designed to be used by themselves throughout the entire procedure. DisCoVisc® OVD, by Alcon, is the only viscous dispersive available.
- Viscous Dispersive
What should you look for when choosing an OVD? See Choosing an OVD to find out.