Intravitreal Injections

Intravitreal injections are injections into an area called the vitreous cavity, which is located at the back of the eye.

What are Intravitreal Injections?

Intravitreal injections are injections into an area called the vitreous cavity, which is located at the back of the eye. The vitreous cavity is filled with vitreous humor gel, a jelly-like fluid. These treatments are performed by an ophthalmologist to inject medications into the eye and treat a variety of different retinal conditions including:

The following substances can be given by intravitreal injections:

  1. Anti-VEGF Medications
  2. Steroidal Implants


What are Anti-VEGF Medications?

Anti-VEGF medications, such as Eylea and Avastin, treat conditions associated with an overproduction of vascular endothelial growth factors (VEGF). VEGFs stimulate the growth of new blood vessels (neovascularization) in the macula and results in increased permeability of existing blood vessels, causing them to leak and swell (edema). Such damage to the macula may result in distorted and blurred vision as the macula is responsible for clear central vision as well as color vision. Anti-VEGF treatments reduces neovascularization and edema by blocking VEGF or inhibiting the activation of VEGF.

What are Steriodial Implants?

Steroidal implants, such as Iluvien and Ozurdex, are alternatives to anti-VEGFs and reduces inflammations and edema associated with diabetic retinopathy and BRVO. The implant releases low levels of steroid therapy in continuous amounts between 3 months and up to 3 years. The implant will dissolve naturally over time.

What Can I Expect During Treatments?

Intravitreal injections are an in-office procedure performed by Dr. Narain.

  1. The eye is anesthetized with numbing drops.
  2. Antibacterial drop + pressure-lowering drop is given.
  3. The conjunctival surface of the eye and the eyelid is cleaned with povidone-iodine, a yellow solution used to sanitize the area around the eye.
  4. A cotton swab dipped into Lidocaine, a numbing anesthetic that blocks pain, is applied to the injection site.
  5. Another cotton swab is used to key the eye open while the medication is injected.

During the injection, patients may feel mild pressure, with little or no pain during the injection itself.


Will I Need Repeated Injections?

Intravitreal injections may need to be repeated every 4-6 weeks depending on the severity of the condition. The need for a repeat injection will be determined during the clinical examination and with the use of diagnostic testing.

What are the Most Common Post-Injection Symptoms?

Common post-injection symptoms include:

  • Blurry vision: this should resolve in a few hours once the dilating drops wear off
  • New floaters: these result from the medication being injected and should resolve within days
  • Subconjunctival hemorrhage: occurs when a blood vessel breaks at the site of the injection (this is usually benign and resolves within a week)
  • Intraocular pressure (IOP) spike: this is a common short-term complication and can be treated with topical medications
  • Scratchy or sandy sensation: we recommend the use of artificial tears for the next 3-4 days
  • Mild pain or discomfort: recommend Tylenol or Ibuprofen as needed

If these symptoms do not resolve within a few days, please call our San Jose office at (408) 294-3534.

Are There Any Risks or Complications?

Severe complications are rare with intravitreal injections but require immediate medical attention to prevent permanent vision loss. The major risks are:

  • Endophthalmitis: inflammation of the intraocular cavities usually associated with a serious infection.

    It is characterized by worsening vision, severe eye pain, pus from the eye, and swollen eyelids following an injection.
  • Retinal detachment: the retina is detached and separated from its blood supply at the back of the eye.

    Retinal detachments require prompt surgery and are characterized by a sudden appearance of many floaters or flashes, reducing peripheral vision, and a large curtain-like shadow over the visual field.

Please call your office immediately if you notice any of these symptoms 2-3 days following an intravitreal injection. Endophthalmitis and retinal detachments must be treated in an appropriate and timely matter to preserve vision.

Request an Appointment in San Jose or Gilroy, California

If you are suffering from a retinal condition or you’re experiencing issues with your vision, contact South Bay Retina today. Dr. Narain is an experienced ophthalmologist and retina specialist, and our practice provides the latest treatments & technology. Schedule at one of our locations in the South Bay: San Jose and Gilroy. Call (408) 294-3534 for our San Jose and Gilroy office. You can also schedule an appointment online by clicking on the button below.


Call us at (408) 294-3534 or request online.

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(408) 294-3534