Steroid injections into the eye deliver medication directly into the vitreous cavity, a jelly-like substance located at the back of the eye. This localized treatment helps limit systemic side effects common with oral steroids. It is commonly employed to manage various eye conditions characterized by inflammation or swelling.
Immediate Post-Injection Experience
Before the injection, numbing drops are applied to the eye, making the procedure largely painless, though a sensation of pressure may be felt. The entire process is brief, usually taking 10 to 15 minutes. Immediately following the injection, temporary visual changes, such as blurring or floaters, are common.
Floaters may appear as dark spots, small black circles, bubbles, or a cloud-like effect. They are often caused by tiny air bubbles or the steroid medication dispersing within the eye. These visual disturbances are transient and typically resolve within a few days to several weeks. Mild discomfort, a gritty sensation, stinging, irritation, or a small red spot at the injection site are also common and subside quickly.
Understanding the Therapeutic Effects
Steroid injections reduce inflammation and swelling within the eye. These medications work by stabilizing the blood-retinal barrier and promoting the reabsorption of excess fluid. They also inhibit the release of inflammatory proteins and substances that contribute to the inflammatory process.
The anti-inflammatory properties of steroids also decrease vascular endothelial growth factor (VEGF), a protein that can cause blood vessels to leak and grow abnormally. Patients may notice symptom improvement within hours to a few days, with full benefits appearing within 7 to 10 days. For chronic conditions, the maximum therapeutic effect might take up to six months.
The duration of the therapeutic effect varies depending on the specific steroid used. For instance, triamcinolone can provide anti-inflammatory effects for several months. Some sustained-release dexamethasone implants can last for three to six months, with others effective for up to two to three years. Repeated injections may be necessary to maintain the desired outcome, depending on the underlying condition and its response to treatment.
Monitoring for Side Effects and Complications
Following a steroid injection, common side effects include mild redness, irritation, or a dry, gritty sensation in the treated eye. A small bleed on the white part of the eye may also occur at the injection site, but this usually resolves within a week.
More serious, though rarer, complications can arise. A significant concern is an increase in intraocular pressure (IOP). This elevation can develop weeks to months after the injection and, if left unmanaged, may lead to glaucoma. Often, this can be controlled with eye drops.
Another potential side effect is the formation or progression of cataracts, which can lead to reduced vision and may require cataract surgery. Although rare, infection inside the eye is a serious complication. Other rare complications include retinal detachment or bleeding into the vitreous gel.
Post-Injection Care and When to Contact Your Doctor
After a steroid injection, avoid rubbing the injected eye for the remainder of the day. Avoid wearing contact lenses for at least two days. To minimize infection risk, refrain from getting water, shampoo, or soap directly into the eye for 48 hours, and avoid swimming for several days to a week. Also, avoid applying eye makeup for 24 hours after the injection.
Continue using any prescribed eye drops and other existing medications as directed by your doctor. Over-the-counter artificial tears can help alleviate dryness or irritation, and cool compresses may also provide comfort. If needed, over-the-counter pain relievers can be used for mild discomfort. Avoid driving or operating heavy machinery immediately after the injection due to temporary visual changes, and wear dark glasses if you experience light sensitivity.
Promptly contact your eye doctor if you experience symptoms indicating a serious complication. These include severe or constant pain, a significant or sudden decrease in vision, or an increase in floaters after the first day. Other concerning signs are new flashing lights, increased sensitivity to light, severe redness, or any eye discharge. Also seek immediate medical attention if you notice a curtain or veil in your vision, or if your symptoms worsen over time.