Intravitreal injections are an essential treatment for many retinal diseases. They allow a medication to be delivered directly inside the eye, as close as possible to the macula, in order to preserve vision. Julien Gozlan, M.D., ophthalmologist in Paris 16, explains the indications, procedure, effectiveness, and follow-up of this now common and painless procedure.
What is an intravitreal injection?
An intravitreal injection involves injecting a medication into the vitreous, the transparent gel that fills the inside of the eye. This route of administration allows direct action on the retina, where the disease is active, while avoiding systemic circulation.
The medications used are primarily anti-VEGF agents (such as ranibizumab, aflibercept, or brolucizumab) and sometimes corticosteroids when inflammation plays a role. The choice depends on the diagnosis and treatment response.
In which cases are intravitreal injections recommended?
Intravitreal injections are indicated in several common ocular diseases:
- Age-related macular degeneration (AMD), wet form.
- Diabetic macular edema associated with diabetic retinopathy.
- Central or branch retinal vein occlusion, for example a central retinal vein occlusion or a branch retinal vein occlusion.
- Certain posterior uveitis cases requiring local anti-inflammatory action.
The goal is to stabilize or improve vision by reducing edema and exudates at the macular level.
How is an intravitreal injection performed?
The procedure is performed in the office in a quiet, aseptic treatment room. After a medical check, anesthetic drops are instilled to numb the eye. Thorough disinfection is performed around the eye.
The physician then performs the intravitreal injection: a fine needle penetrates the wall of the eye at a distance from the cornea to deliver the medication into the vitreous. The procedure takes a few seconds and is completely painless. Most patients feel a slight pressure but never pain.
After the injection
It is common to experience slight redness, a gritty sensation, or to see a small bubble in the visual field for a few hours. These symptoms resolve spontaneously. An antiseptic and lubricating eye drop is prescribed for a few days.
How often are intravitreal injections performed?
The most common regimen begins with three monthly intravitreal injections, called the loading phase, then the frequency is adjusted based on the response observed on the macular OCT (retinal scan). This treat and extend protocol allows sessions to be gradually spaced out if the retina remains stable.
Each eye is treated independently, according to its progression. The total number of injections varies from patient to patient, and their effectiveness depends primarily on the regularity of follow-up.
Results and treatment effectiveness
International studies have shown that intravitreal injections can preserve vision in more than 90% of cases and achieve significant improvement in one out of three patients. The effect is often visible within the first few weeks, especially when treatment is initiated early.
The goal is to maintain the best possible vision in the long term while limiting the progression of the retinal disease.
In France, these practices are governed by updated guidelines from professional societies, available in a reference publication dedicated to best practices for intravitreal injections.
Possible side effects
Serious complications are extremely rare (infection, intraocular inflammation). They are prevented by rigorous aseptic measures. The most common minor effects are a small subconjunctival hemorrhage or temporary discomfort.
Follow-up after intravitreal injection
A macular OCT examination is performed regularly to assess treatment response. This painless scan measures the resolution of edema and helps adjust the injection schedule.
It is essential to not discontinue treatment without medical advice: continuity ensures visual stability and prevents relapses. In parallel, certain conditions underlying intravitreal injections, such as diabetic retinopathy or retinal vein occlusions, require dedicated follow-up.
FAQ: frequently asked questions about intravitreal injections
Is the intravitreal injection painful?
Before the intravitreal injection, anesthetic drops are instilled to numb the surface of the eye. Most patients feel at most a slight pressure but no real pain. A minor discomfort or gritty sensation may persist for a few hours, relieved by the eye drops prescribed after the session. If significant pain occurs afterward, it is important to promptly notify the treating physician.
Can I drive after an intravitreal injection?
Right after the intravitreal injection, vision may be blurry for a few hours due to the drops, the light used, and sometimes a small bubble visible in the field of vision. It is therefore recommended to not drive immediately after the session and to come accompanied or use transportation. In most cases, functional vision returns within the day and driving can be resumed when you feel visually comfortable and safe, following the advice given at the practice.
What signs should concern me after an intravitreal injection?
Slight redness, moderate discomfort, or seeing a small bubble are normal and temporary symptoms. However, you should seek emergency care in case of significant pain, marked redness, sudden vision loss, or a sensation of a dark curtain in front of the eye. These signs may indicate an intraocular infection or a retinal complication that must be managed without delay. If in doubt, it is best to promptly call the practice or the ophthalmological emergency department.
Should I stop my usual medications (anticoagulants, aspirin) before an intravitreal injection?
In the vast majority of cases, systemic treatments such as anticoagulants or aspirin are not discontinued for an intravitreal injection, so as not to disrupt your general health status. They may cause small superficial subconjunctival hemorrhages, which appear impressive but are harmless to vision. Any potential modification of these treatments is never made without joint consultation between the ophthalmologist and the primary care physician or cardiologist.
How long does intravitreal injection treatment last?
The duration of intravitreal injection treatment depends on the retinal disease being treated and how your eye responds to the medication. Some patients require only a limited number of injections, while others need to be monitored and treated over several years with a gradually extended interval. The goal is always to find the right balance between effectiveness, comfort, and number of sessions, based on regular check-ups, particularly through macular OCT.
What happens if I miss or reschedule an injection appointment?
A slight delay of a few days is rarely problematic, but repeated delays or the cancellation of several sessions can promote disease reactivation (for example AMD or macular edema). If something comes up, it is important to reschedule the intravitreal injection as soon as possible rather than postponing it indefinitely. Regularity of follow-up and the injection schedule is a key factor in preserving long-term vision.
Can I shower, wear makeup, or exercise after an intravitreal injection?
Daily activities can generally be resumed quickly after an intravitreal injection. However, during the first 24 hours, it is advisable to avoid getting soapy or irritating water directly into the treated eye and not to wear eye makeup. Gentle physical activities are permitted, but contact sports or activities with high exposure to dust should be postponed for a few days. Specific precautions are provided at the time of departure from the practice.
Are intravitreal injections safe in the long term?
There is now extensive experience with intravitreal injections, which have been performed for many years in a large number of patients. Serious complications remain exceptional thanks to strict adherence to aseptic and follow-up protocols. As with any treatment, intravitreal injections may cause local or systemic side effects, assessed on a case-by-case basis depending on your age, medical history, and the retinal condition being treated. The benefit-to-risk ratio is discussed during the consultation before initiating or continuing the protocol.
📍 Consultation at the Paris – Auteuil Ophthalmology Practice
Julien Gozlan, M.D. sees you at the Paris – Auteuil Ophthalmology Practice for a comprehensive macular assessment, including an OCT examination and a personalized discussion about the indication for intravitreal injection treatment.
Book an AppointmentFurther reading
- Macular OCT: the gold standard examination for monitoring the effectiveness of intravitreal injections.
- Age-related macular degeneration (AMD): the most common cause requiring intravitreal injections.
- Diabetic macular edema: another major indication for injection treatment.