Over the past seven to eight years more and more of retina doctors’ time is spent treating eye conditions with injections. These are not injections that go into the eyelid or around the eye or the skin of the eye, but actually into the inside of the eyeball. When I was in-training during the ’90’s, injecting into the eye was generally felt to be a dangerous endeavor, to be avoided at all costs, only done in extreme circumstances. Today, more than half the patients who I see each day are there with conditions that benefit from medication placed on the very inside of the eye.
Fortunately and surprisingly, these injections are almost painless for the majority of my patients. The greatest danger is getting an infection inside the eye since the barrier between the inside of the eye and the outside world is momentarily breached. Most doctors insist on using an iodine solution to sterilize the outside of the eye. This can be quite irritating to the eye so the first step in an injection is numbing the outside with drops. Other retinologists may numb with an injection of anesthetics but I find that is not necessary in most patients. The issue of iodine allergy comes up frequently. Iodine is a mineral essential for life so one cannot be allergic to it just like patients cannot be allergic to oxygen or glucose. Patients tell us that they are allergic to seafood and since seafood has iodine in it, they must be allergic to iodine. Of course seafood has other complex chemicals, most commonly tropomyosin and parvalbumins, that are actually the cause of seafood allergies. These are not in our iodine preparations. No other preparation works anywhere near as well as iodine so we try to convince every patient to use this and that it is worth the irritation that some patients experience to avoid infection.
After the injection, patients have no restrictions except swimming for three days. We also recommend having a driver because the eye is usually patched for a few hours to prevent injury because of the numbness.
Depending on the condition being treated, the injections are usually a medication not a cure, meaning that once the patients stop getting the injections the disease comes back and vision decreases. Age related macular degeneration is the most common disorder treated with injections and usually needs continued treatment every one to three months. Other common uses of injections are diabetic eye disease and vein occlusions. The results in many cases are much better than in the past when the only treatment was laser. Some of my patients who lost most of the vision in one eye ten or more years ago, often say that they wish that injection treatment had been invented earlier.