Subconjunctival injection

Schematic diagram of the human eye en

Subconjunctival injection is a medical procedure involving the injection of medication or other therapeutic agents directly into the subconjunctival space, which lies between the conjunctiva and the sclera of the eye. This method is commonly used for delivering drugs for the treatment of various eye diseases and conditions, such as infections, inflammation, and allergies. The primary advantage of subconjunctival injection is that it allows for direct delivery of medication to the target area, potentially increasing the drug's efficacy and reducing systemic side effects.

Indications

Subconjunctival injections are indicated for a variety of ocular conditions. These include, but are not limited to:

• Bacterial conjunctivitis
• Viral conjunctivitis
• Fungal infections of the eye
• Uveitis
• Corneal ulcers

Procedure

The procedure for administering a subconjunctival injection involves several steps. Firstly, the patient's eye is numbed using a topical anesthetic. The eye is then cleaned and sterilized to prevent infection. Using a fine needle, the doctor carefully injects the medication into the subconjunctival space, ensuring not to penetrate too deeply and damage the eye. The volume of medication injected typically ranges from 0.1 to 0.5 ml, depending on the drug's concentration and the condition being treated.

Advantages

Subconjunctival injections offer several advantages over other drug delivery methods, such as topical eye drops or systemic administration. These include:

• Direct delivery of medication to the affected area, increasing drug concentration at the site of pathology.
• Bypassing the blood-eye barrier, which can limit the effectiveness of systemically administered drugs.
• Reduced systemic absorption, minimizing the risk of side effects.

Risks and Complications

While generally safe, subconjunctival injections can be associated with certain risks and complications, including:

• Hemorrhage in the subconjunctival space
• Infection
• Injury to the eye from the needle
• Allergic reactions to the medication

Aftercare

Following the injection, patients may experience mild discomfort, redness, or a foreign body sensation in the eye. These symptoms usually resolve within a few days. Patients are advised to avoid rubbing the eye and to follow any specific aftercare instructions provided by their healthcare provider.

Conclusion

Subconjunctival injections are a valuable tool in the treatment of various eye conditions, offering targeted drug delivery with minimal systemic side effects. However, like all medical procedures, they carry certain risks and should only be performed by qualified healthcare professionals.