Intravitreal administration

Intravitreal administration refers to a medical procedure involving the injection of medications directly into the eye's vitreous cavity. This method is primarily used for treating various retinal diseases, including age-related macular degeneration (AMD), diabetic retinopathy, and retinal vein occlusion. By delivering drugs directly to the site of pathology, intravitreal injections can provide high concentrations of therapeutic agents where needed, while minimizing systemic exposure and side effects.

Indications

Intravitreal administration is indicated for a range of ocular conditions, notably:

• Age-related macular degeneration (AMD), particularly the wet form, which involves abnormal blood vessel growth under the retina.
• Diabetic retinopathy, especially in cases where there is significant macular edema.
• Retinal vein occlusion, which can lead to macular edema and vision loss.
• Endophthalmitis, a severe eye infection, as a method of delivering antibiotics directly to the affected area.
• Uveitis, to reduce inflammation inside the eye.

Procedure

The procedure for intravitreal injection must be performed under sterile conditions to minimize the risk of infection. It typically involves the following steps:

1. The patient's eye is numbed using topical anesthetic drops.
2. The eye and surrounding area are cleaned with antiseptic solution to reduce the risk of infection.
3. A speculum is used to keep the eye open during the procedure.
4. The medication is injected through the sclera (the white part of the eye) into the vitreous cavity, using a fine needle.
5. After the injection, the eye is monitored for a short period for any immediate complications.

Complications

While intravitreal injections are generally safe, they can be associated with certain complications, such as:

• Endophthalmitis, a serious infection of the internal parts of the eye.
• Retinal detachment, where the retina separates from the back of the eye.
• Increased intraocular pressure, which can lead to glaucoma if not managed.
• Cataracts, or clouding of the eye's natural lens, particularly with repeated injections.

Drugs Used

Several medications are commonly administered via intravitreal injection, including:

• Anti-VEGF agents (e.g., Ranibizumab, Aflibercept, and Bevacizumab) for treating wet AMD and other conditions involving neovascularization.
• Corticosteroids (e.g., Triamcinolone acetonide, Dexamethasone implant) for managing inflammation and macular edema.
• Antibiotics for treating endophthalmitis.

Conclusion

Intravitreal administration is a critical procedure in the management of various retinal diseases. It allows for direct delivery of therapeutic agents to the affected area, offering the potential for improved visual outcomes. However, the procedure does carry risks, and it is essential for it to be performed by experienced healthcare professionals in a sterile environment to minimize complications.