Intra-Vitreal Injection: Explained
Intra-vitreal injections have rapidly become the most commonly performed procedure in ophthalmology. According to the Center for Medicare Services, more than 2.6 million intra-vitreal injections were performed for Medicare patients in 2014.
What is an intra-vitreal injection?
This procedure involves the delivery of a small volume of medicine into the vitreous cavity, the largest space in the eye. A variety of vision-threatening retinal conditions can be treated to successfully restore vision and prevent irreversible vision loss through the use of these injections, which have been available and evolved since 2005. Retinal thickening and swelling due to diabetes, age-related macular degeneration, and other vascular disorders are the most commonly treated conditions.
Is the intra-vitreal injection painful?
This question is the most common concern among patients receiving their first intra-vitreal injection. The vast majority of intra-vitreal injections are very well-tolerated with minimal pain. Tremendous care is taken in the anesthetic preparation for the procedure in order to minimize discomfort. Multiple doses of local anesthesia are administered over a period of 10-15 minutes to numb the eye surface so that the procedure can be performed with minimal sensation, although some eye pressure or a slight pinch may be felt, and the experience may vary from patient to patient.
How many injections will I need?
Each injection is performed approximately one month apart, and most conditions require at least 3 injections to restore or improve the vision. After the third month / third injection, optical coherence tomography (OCT), a high-resolution cross-sectional scan of the retina, is repeated to assess the progress with treatment. These results will inform the decision to halt injections, or continue the same regimen, or switch to an injection with a different medication.
What should I expect at my intra-vitreal injection appointment?
After check-in, the clinic staff will escort you to an exam room to check your vision and eye pressure. Unlike your previous appointment where the eyes were dilated, one of the major advantages of the injection appointment is that no dilation or OCT scan is required, making the appointment much faster. Next, your eye will be prepared for injection with multiple doses of anesthetic drops and gel over a period of 10-15 minutes. If your right eye is receiving the injection, it is helpful for you to look to the left as each dose is applied; not by turning your head, but by pointing your eyes toward the wall to your left. If your left eye, then you’ll want to point your eyes to the right while the anesthetic is applied. After 10-15 minutes, Dr. Kavoussi will apply sterilizing drops to the eye surface and place a small eyelid speculum to comfortably maintain the eyelids open. He will add one to two more doses of sterilizing drops, and then he administers the injection. The injection itself lasts a mere few seconds, but the 10-15 minutes of preparation are necessary to keep the procedure comfortable. Immediately following the injection, Dr. Kavoussi will rinse the surface of the eye with a cool sterile eye wash.
Any risks or side effects to be aware of?
The most serious risk is infection, which is very rare with reported rates from 1/5,000 to 1/10,000. The warning signs of infection are worsening redness, pain, and/or vision a few days following this injection. If any of these symptoms occur, it is important to return for a check, even if after hours. Other common side effects are redness on the white of the eye that can last for 2-4 weeks, or scratchiness/irritation of the eye surface that can last for a few hours. Artificial tears / lubricating drops such as Refresh preservative-free are helpful to relieve any surface irritation.
Can I return to work after the injection?