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Book

Intravitreal Implants

Sashwanthi Mohan  1 , Dhanashree Ratra  2
In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan.
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Affiliations
Book

Intravitreal Implants

Sashwanthi Mohan et al.

Excerpt

The intravitreal route is the main route of drug administration to treat diseases affecting the posterior segment of the eye. Intravitreal implants are specially designed to release drugs in a controlled manner over a longer duration. It helps to directly deliver the drug to the vitreous, thus overcoming systemic pathways and obtaining a high drug concentration in the vitreous chamber.

Intravitreal implants can either be non-biodegradable (NBI) or bio-degradable (BI). NBIs are longer lasting as they can achieve near zero-order release kinetics. Since they are non-degradable, they need surgical removal or replacement. They are larger in size; hence, a larger incision is required for implantation. They are made up of ethylene vinyl acetate (EVA), polyvinyl alcohol (PVA), or polysulfone capillary fiber (PCF).

Examples of the available NBIs are Vitrasert and Retisert. BIs have the advantage of not requiring surgical removal or replacement as they degrade and disintegrate over time, thus eliminating all components from the body. They are made of polylactic acid (PLA), polyglycolic acid (PGA), PLGA, or polycaprolactones. An example of the available BI is a steroid implant containing dexamethasone called DEX Implant (Ozurdex).

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Conflict of interest statement

Disclosure: Sashwanthi Mohan declares no relevant financial relationships with ineligible companies.

Disclosure: Dhanashree Ratra declares no relevant financial relationships with ineligible companies.

References

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