Potential side effects of anti-VEGF eye injections : Floaters

Dr. Michael Dollin, MD, FRCSC, Ophthalmologist

Duration: 3 minutes and 23 seconds

If you have a condition such as wet macular degeneration or retinal vein occlusion, your eye doctor may be administering injections into your eyes. These injections are generally very safe and are the most likely treatment to stabilize and ideally improve your vision.

Anti VEGF injections are generally very safe, but there are some risks that come with these treatments. One of the rarest but most potentially concerning side effects is a 1 in 3000 risk of infection. Your doctor will sterilize your eye before treatment and reduce this risk to as low as possible but there is always a very small risk of infection in the eye because a tiny needle is inserted into the eye to deliver the medicine and that is always a pathway where bacteria could theoretically enter your eye. This is incredibly rare, but when it occurs, patients typically notice worsening vision, pain and increasing eye redness approximately two to three days from the injection.

These infections are generally treatable with antibiotics but it's important to reach out to your eye care provider as soon as possible because the sooner antibiotics are administered, the better the outcomes are likely to be.

Other complications can occur with anti VEGF injections. Typically, iodine is used to sterilize the eye prior to treatment and afterwards there can be irritation in the eye for a day or so. This is something to be aware of and if you have significant pain, make sure that you follow up with your eye care provider as there are other complications that can mimic this that could be more serious.

Similarly, there's often a small patch of blood that can be seen on the white part of the eye at the site where the injection is given that usually is of no concern beyond the cosmetic appearance of that small hemorrhage. If the vision is good and the eye is comfortable, a small hemorrhage on the eye is nothing to worry about.

Sometimes after injections there can be floaters in the eye. Floaters are formed when microscopic collagen fibres clump together in the vitreous of the eye and cast tiny shadows on to the retina. They are typically seen as tiny spots in your vision. Floaters usually resolve on their own after a few days.

Patients may also notice a swirling of medicine inside their eye after the injection and sometimes even a small black dot. Typically, this is a small bubble of gas that may have been present in the syringe prior to injection, and usually resolves within a day or two. The swelling of the medicine will also resolve quickly usually within a few hours as the medicine circulates through the eye. Immediately after the injection it's also possible for the eye to go dark. This is caused if the pressure in the eye goes up quite high due to injecting liquid into the eye. This will usually resolve within a few minutes. If the vision remains dark for a prolonged period of time your eye physician may also reduce the pressure by taking some pressure out of the eye. In general, the pressure returns to normal within about half an hour of the injection.

If you have glaucoma it may be worth discussing ways of lowering the pressure before your injections with your doctor. If your glaucoma is more advanced or if you're on numerous pressure lowering drops you should have a discussion with your eye doctor.

For more information on the potential side effects and complications of getting anti-VEGF injections in your eyes, please speak to your local eye specialist or ophthalmologist.

Presenter: Dr. Michael Dollin, Ophthalmologist, Ottawa, ON

Local Practitioners: Ophthalmologist