An intravitreal injection is a method for administering medication directly into the vitreous humor, the clear, gel-like substance that fills the back of the eye. This procedure is a common and effective way to deliver high concentrations of therapeutic drugs to the retina, while minimizing systemic effects on the rest of the body. These injections are primarily used to treat serious retinal conditions such as “wet” Age-related Macular Degeneration (AMD), diabetic retinopathy, and retinal vein occlusion. Medications like anti-VEGF agents or steroids reduce fluid leakage, slow abnormal blood vessel formation, and decrease inflammation, helping preserve vision.
Preparing for the Injection Appointment
Preparation focuses on hygiene and logistics. You should discuss current medications, particularly blood thinners, with your physician beforehand, though they are usually continued unless otherwise instructed. On the day of your appointment, avoid applying makeup, lotions, or creams near the eye to minimize contaminants.
Since the procedure uses numbing and sometimes dilating drops, your vision may be temporarily blurred or sensitive to light afterward. Arrange for a responsible adult to drive you home, as operating a vehicle immediately following the injection is unsafe. Bringing sunglasses helps manage light sensitivity if your pupils are dilated. A light meal before arriving is also advisable to maintain stable blood sugar levels.
The Injection Procedure Step-by-Step
The entire intravitreal injection process, from preparation to completion, is quick, often lasting only 10 to 15 minutes, though the full office visit takes longer. The procedure begins with the application of a topical anesthetic, usually in the form of drops or a gel, which thoroughly numbs the surface of the eyeball to prevent pain. A series of these drops may be administered to ensure the eye is completely insensitive to touch.
After the eye is anesthetized, the area is meticulously cleaned with an antiseptic solution, most commonly povidone-iodine, which is applied to the eyelids and the surface of the eye itself. This step is performed to drastically reduce the natural bacterial flora around the eye and prevent the rare, but serious, complication of infection. You may feel a slight, temporary burning or stinging sensation from the antiseptic, which is a normal part of the sterilization process.
A small instrument known as an eyelid speculum is then gently placed to hold the eyelids open and prevent blinking during the injection itself. The physician will ask you to look in a specific direction, typically away from the planned injection site. The injection is administered using an extremely fine, short needle that penetrates the sclera, the white part of the eye, a precise distance behind the cornea.
During the moment of injection, many patients report feeling a sensation of pressure or a cold feeling, but generally not pain, due to the effective numbing. The actual delivery of the medication is very fast, taking only a few seconds. Following the injection, the speculum is removed, and the eye may be rinsed to remove residual antiseptic. An antibiotic drop may be applied as a final measure to further safeguard against infection.
Immediate Recovery and Aftercare
Immediately following the procedure, temporary and harmless sensations are common. Patients often notice scratchiness, mild irritation, or a feeling like an eyelash is in the eye, which is a residual effect of the antiseptic and the speculum. This mild discomfort usually subsides within a day or two.
You may observe a small, mobile floater in your vision, often described as a bubble or black spot, which is the medication or a tiny air bubble. This phenomenon is expected and will naturally dissolve and clear from your field of vision, typically within a few hours or by the next day. Another frequent sign is a bright red spot at the injection site, known as a subconjunctival hemorrhage. This painless bruise on the eye’s surface will clear up on its own within one to two weeks.
To facilitate healing, strictly avoid rubbing the injected eye for the rest of the day. Avoid using contact lenses and swimming for two to three days to minimize the risk of irritation or infection. Your doctor may recommend lubricating drops to alleviate any persistent grittiness.
While complications are uncommon, be aware of warning signs indicating a potential problem, such as an infection. Contact your physician immediately if you experience severe, increasing pain not relieved by over-the-counter medication. Other signs requiring urgent attention include a significant, sudden decrease in vision, increasing redness, swelling, or any discharge from the eye.