Intravitreal Chemotherapy

• Intravitreal chemotherapy delivers anti-cancer drugs directly into the eye’s vitreous cavity.
• It is a vital treatment for preserving vision and the eye in specific ocular cancers.
• The procedure involves careful injection, often under general anesthesia, to target tumors effectively.
• Retinoblastoma is a primary indication, where it helps control tumor growth and prevent metastasis.
• Potential side effects range from temporary eye irritation to more serious, though rare, complications like infection or retinal detachment.

What is Intravitreal Chemotherapy?

Intravitreal chemotherapy refers to a highly specialized medical procedure where anti-cancer medications are directly injected into the vitreous cavity of the eye. This targeted delivery method allows for high concentrations of chemotherapy drugs to reach ocular tumors while minimizing systemic exposure and its associated side effects. The vitreous humor is the clear, gel-like substance that fills the space between the lens and the retina. By injecting directly into this space, the drugs can act locally on cancerous cells, making it an effective strategy for treating certain eye cancers. This approach is particularly beneficial for conditions where systemic chemotherapy might not adequately penetrate the eye’s natural barriers or where localized treatment is preferred to reduce overall toxicity.

Intravitreal Chemotherapy Procedure and Its Role in Retinoblastoma

The intravitreal chemotherapy procedure involves the careful administration of chemotherapy agents into the eye. Typically performed in a sterile environment, often under general anesthesia, especially for pediatric patients, the eye is prepared with antiseptic solutions. A very fine needle is then used to inject the medication into the vitreous cavity, usually through the pars plana, a specific region of the eye wall. The amount and type of drug are precisely controlled based on the patient’s condition and the specific cancer being treated. After the injection, the patient is monitored for any immediate reactions.

This treatment is particularly significant for intravitreal chemotherapy for retinoblastoma, a rare but aggressive eye cancer that primarily affects young children. Retinoblastoma can present with intraocular seeding, where cancer cells spread within the vitreous or subretinal space. In such cases, intravitreal chemotherapy has revolutionized treatment by directly targeting these seeds, significantly improving the chances of eye preservation and vision salvage. Before its widespread adoption, eyes with significant vitreous seeds often required enucleation (surgical removal of the eye). Studies have shown high rates of tumor control and eye preservation with this method. For instance, a meta-analysis published in the Journal of Clinical Oncology indicated that intravitreal chemotherapy achieved eye preservation in a significant percentage of eyes with vitreous seeds, often exceeding 80-90% in selected cases.

• Patient preparation and anesthesia.
• Sterilization of the eye and surrounding area.
• Precise injection of chemotherapy drug into the vitreous.
• Post-injection monitoring for complications.

Potential Side Effects of Intravitreal Chemotherapy

While highly effective, intravitreal chemotherapy side effects can occur, though they are generally localized to the eye. The most common side effects are usually mild and temporary, reflecting the direct impact of the injection and the drug itself on ocular tissues.

Common side effects may include:

• Temporary eye irritation or redness at the injection site.
• Mild pain or discomfort in the eye.
• Transient blurred vision.
• Small subconjunctival hemorrhage (a minor bruise on the white of the eye).

More serious, but rare, complications can include infection (endophthalmitis), a severe inflammation inside the eye, which can lead to vision loss; retinal detachment, where the retina pulls away from its normal position; cataract formation, though less common with modern techniques; vitreous hemorrhage (bleeding into the vitreous); and localized damage to the retina or optic nerve, depending on the drug and dosage. Patients undergoing intravitreal chemotherapy are closely monitored by their ophthalmologist for any signs of these complications. Early detection and management are crucial for minimizing long-term adverse effects and ensuring the best possible visual outcomes. The benefits of preserving the eye and vision, especially in conditions like retinoblastoma, generally outweigh the risks of these potential side effects.