Why are intraocular injections given?
Intraocular injections are used to deliver a high dose of medicine into the eye to treat retinal diseases. They may be given to dry up new vessels so that they do not bleed. They may be given to decrease swelling of the macula or for severe inflammation. Hence they are commonly given for diabetic retinopathy, age related macular degeneration, retinal vein occlusions, macular edema, uveitis, retinitis.
Which injections are given?
The commonly given injections are Bevacizumab (Avastin), Ranibizumab (Lucentis), Pegaptanib sodium (Macugen) and Triamcinolone (Tricort/Kenacort), Ganciclovir, Cidofovir and anti-inflammatory drugs.
What is the procedure and does the injection hurt?
The injections are given in the operation theatre as it has to be done with complete sterility. It is best to have the blood sugars and blood pressure well controlled before the injection. Blood thinning medication does not need to be stopped. The pupils are dilated and numbing drops are put. The injection is given using the operating microscope. A ‘very fine needle’ is used and hence there is little discomfort. The entire procedure takes a few minutes. The eye is patched for a few hours and if triamcinolone has been injected it is advised to remain seated for 4 hours after the injection and not to lie flat.
The side effects are minimal. There can be a small hemorrhage at the site of injection making a part of the eye look red but it clears up in a few days. You may see some ’floaters’ that may be due to seeing the drug itself or on seeing an air bubble that may have been injected. They will disappear after some time. Mild pain may be there but significant pain must be reported to the doctor and could result from an abrasion of the cornea, rise in the eye pressure or rarely due to an infection.
How do I prepare for the procedure?
- Make sure you understand the indication along with the potential risks of the procedure
- Do not wear eye makeup on the day of the procedure
- Inform your doctor if you regularly use eye drops such as glaucoma drops or artificial tears
- Notify your doctor of any infection or inflammation in or around your eyes or if you have a cold or flu
- Notify your doctor if you have allergies to iodine or xylocaine
- Arrange for someone to drive you to and from your appointment.
Do injections need to be repeated?
The effect of the commonly injected medications lasts for 1-3 months. If the disease needs further management then the medication needs to be injected again. It is common for these injections to be given several times.