Intravitreal Steroid Injections for Retinal Conditions
Understanding Intravitreal Steroid Injections
An intravitreal steroid injection places a small amount of corticosteroid medication directly into the vitreous, the gel-like substance that fills the inside of the eye. By delivering the drug to the site where it is needed, the injection provides a high concentration of medication in the eye while limiting the side effects that can occur with steroids taken by mouth or through an IV.
Corticosteroids used in these injections reduce inflammation, decrease swelling, and help restore the natural barrier that keeps fluid from leaking into the retina. They are not the same as anabolic steroids used for muscle building.
Corticosteroids bind to specific receptors inside cells, which changes how certain genes are expressed. This process reduces the production of inflammatory substances such as interleukin-6, interleukin-8, prostaglandins, and vascular endothelial growth factor (VEGF). By lowering these chemical signals, the steroid calms the immune response that drives swelling and blood vessel leakage in the retina.
Steroids also strengthen the tight junctions between cells in the retinal pigment epithelium and blood vessel walls. This helps restore the blood-retinal barrier, the protective layer that normally prevents fluid and proteins from seeping into the retina and causing vision problems.
Anti-VEGF agents such as Eylea (aflibercept), Lucentis (ranibizumab), and Avastin (bevacizumab, used off-label for eye conditions) work by blocking a single growth factor that drives abnormal blood vessel growth and leakage. Steroids take a broader approach, targeting multiple inflammatory pathways at once. This makes steroids especially useful when inflammation, not just VEGF, is a major driver of the eye disease.
A retina specialist may choose a steroid injection when anti-VEGF therapy alone has not controlled macular edema, or when the underlying condition involves significant inflammation, such as uveitis.
Conditions Treated With Intravitreal Steroids
Diabetic macular edema (DME) occurs when diabetes-related damage to retinal blood vessels causes fluid to leak into the macula, the central part of the retina responsible for sharp vision. Anti-VEGF injections are often the first treatment. However, when DME does not respond well to anti-VEGF therapy, or when a patient has other factors such as an artificial lens implant, a retina specialist may recommend a steroid injection or implant.
A retinal vein occlusion (RVO) happens when a vein carrying blood away from the retina becomes blocked. The blockage causes blood and fluid to back up, leading to swelling in the macula. Steroid injections or implants can reduce the inflammation and fluid buildup that follow vein occlusions, helping to stabilize or improve vision.
Uveitis is inflammation of the uvea, the middle layer of the eye. When uveitis affects the back of the eye (intermediate, posterior, or panuveitis) and does not respond to eye drops alone, intravitreal steroids can deliver concentrated anti-inflammatory treatment directly where the inflammation is occurring. This approach is especially valuable for patients with chronic or recurring uveitis.
Retina specialists may also use intravitreal steroids for certain cases of sympathetic ophthalmia, temporal arteritis affecting the eye, and other ocular inflammatory diseases that do not respond to topical corticosteroid drops. The decision depends on the specific condition and how well the patient has responded to other treatments.
Types of Intravitreal Steroid Medications
Triamcinolone acetonide is the most widely used intravitreal steroid. Kenalog-40 (triamcinolone acetonide, 40 mg/mL) has been used as an intravitreal injection since 2004 for several retinal diseases. It is important to know that Kenalog-40 is FDA-approved only for intramuscular and intra-articular use and is used off-label when injected into the eye.
Preservative-free formulations are also available. Triesence (triamcinolone acetonide, 40 mg/mL) and Trivaris (triamcinolone acetonide, 80 mg/mL) are FDA-approved for ophthalmic use in conditions such as uveitis and other inflammatory eye diseases that have not responded to topical steroids. These preservative-free options may reduce the risk of certain complications.
Ozurdex (dexamethasone intravitreal implant, 0.7 mg) is a small, biodegradable implant placed inside the eye through a thin applicator. It slowly releases dexamethasone over several months, providing sustained anti-inflammatory treatment without the need for monthly injections. Ozurdex was FDA-approved for macular edema due to retinal vein occlusion in 2009, for non-infectious uveitis in 2010, and for diabetic macular edema in 2014.
The sustained-release design of Ozurdex uses a solid polymer that gradually breaks down inside the eye. This controlled release helps maintain therapeutic drug levels over an extended period, typically around four to six months.
Iluvien (fluocinolone acetonide intravitreal implant) is a tiny, non-biodegradable implant that continuously releases a low dose of fluocinolone acetonide for two to three years after a single injection. This long-acting option can reduce the number of treatments needed for patients with chronic diabetic macular edema. Because of its extended duration, careful monitoring for side effects is essential.
A newer delivery method places triamcinolone into the suprachoroidal space, the area between the outer wall of the eye (sclera) and the choroid. This approach was FDA-approved based on the PEACHTREE clinical trial for use in non-infectious uveitis. By targeting the medication closer to the back of the eye, suprachoroidal delivery may provide similar retinal drug levels while potentially causing less pressure elevation and fewer cataracts compared to traditional intravitreal injection.
Who May Benefit and Risk Factors to Consider
Patients who may benefit from intravitreal steroid treatment include those with diabetic macular edema that has not responded fully to anti-VEGF therapy, patients with macular edema from retinal vein occlusion, and individuals with non-infectious uveitis affecting the posterior segment of the eye. Patients with an artificial lens implant (pseudophakic patients) are often good candidates because steroid-induced cataract is not a concern for them.
Certain patients face a greater risk of side effects from intravitreal steroids. Those with a diagnosis of primary open-angle glaucoma (POAG) or a first-degree relative with POAG are more likely to experience steroid-related pressure increases. Among adults with POAG, the proportion who are steroid responders can be as high as 90% (Glaucoma Today, 2015). Other risk factors include high myopia, connective tissue disease, type 1 diabetes, and a history of pressure elevation after previous steroid use.
Before recommending a steroid injection, a retina specialist will review the patient's eye pressure history, lens status (natural lens versus artificial lens), glaucoma risk factors, and response to previous treatments. This information helps determine which steroid formulation and delivery method is most appropriate. Patients should share their full medical and eye history, including any family history of glaucoma.
What to Expect During the Procedure
The injection is performed in the retina specialist's office. The eye is numbed with anesthetic drops or a small injection of local anesthetic around the eye. The skin around the eye and the surface of the eye are cleaned with an antiseptic solution, typically povidone-iodine, to reduce the risk of infection. A small speculum may be placed to keep the eyelids open.
The retina specialist uses a very thin needle to inject the steroid medication through the white part of the eye (sclera) into the vitreous cavity. The injection itself takes only a few seconds. For implant-based treatments like Ozurdex, a small applicator is used to place the implant inside the eye. Most patients feel pressure during the injection. Some discomfort is normal, but the numbing medication helps minimize it.
After the injection, the retina specialist may check the eye pressure and examine the eye briefly. Patients may notice temporary blurred vision, mild redness, or a feeling of something in the eye. With triamcinolone injections, small white particles (the drug suspension) may be visible as floaters for a few days. These typically settle to the bottom of the eye and dissolve over time. Most patients can return to normal activities the same day.
Possible Side Effects and Complications
The most common side effect of intravitreal steroids is elevated intraocular pressure (IOP). A meta-analysis of 115 studies found that 32.1% of patients treated with intravitreal triamcinolone acetonide developed ocular hypertension with an IOP of 21 mmHg or greater (Glaucoma Today, 2015). With certain doses, eye pressure elevation may occur in up to 40% to 60% of patients (AAO, Current Insight). The risk increases with higher doses; a 25 mg dose was associated with a 45.9% rate of pressure elevation compared to 32.1% with a 4 mg dose (Glaucoma Today, 2015).
In most cases, elevated pressure is temporary and can be managed with one or more glaucoma eye drops. In rare cases, patients may require a procedure to lower the pressure if drops are not sufficient.
Steroid use in the eye can accelerate cataract development. Cataract occurs in up to 45% of patients within a year of triamcinolone injection (AAO). This is a significant consideration for patients who still have their natural lens. Patients who already have an artificial lens implant from previous cataract surgery do not face this risk.
Endophthalmitis, a serious infection inside the eye, is a rare but potentially vision-threatening complication. The incidence following intravitreal Kenalog injections is approximately 1 in 500 to 1 in 1,000 (AAO EyeNet). Strict sterile technique during the procedure helps minimize this risk. Symptoms of endophthalmitis include increasing pain, worsening vision, and increased redness in the days following injection.
Less common complications include retinal detachment, vitreous hemorrhage (bleeding inside the eye), and migration of a steroid implant to the front of the eye. While these events are rare, they may require additional treatment or surgery. Patients should be aware of warning signs and contact their retina specialist promptly if any unusual symptoms develop.
Living With Intravitreal Steroid Treatment
Regular follow-up visits are essential after an intravitreal steroid injection. A retina specialist will check eye pressure, monitor for cataract progression, and evaluate whether the swelling in the retina has improved. Follow-up typically occurs within one to two weeks after the injection and then at regular intervals. Patients receiving long-acting implants like Iluvien (fluocinolone acetonide) may need monitoring for two to three years after placement.
Many retinal conditions are chronic and may require more than one steroid injection over time. Sustained-release implants like Ozurdex (dexamethasone implant) can reduce the frequency of injections compared to traditional steroid injections. A retina specialist will develop a treatment plan based on how the eye responds and will adjust the approach if side effects like elevated pressure or cataract progression occur.
Most patients can resume normal daily activities shortly after the injection. The retina specialist may recommend avoiding rubbing the eye, swimming, or heavy lifting for a brief period after treatment. Using prescribed eye drops as directed helps prevent infection and manage pressure. Patients with diabetes should continue to manage blood sugar levels, as good systemic control supports better eye health.
When to See a Retina Specialist
Contact a retina specialist or go to the emergency room immediately if any of the following symptoms occur after an intravitreal steroid injection:
- Sudden decrease in vision or sudden vision loss
- Increasing eye pain that does not improve
- Significant increase in redness of the eye
- New flashes of light or a sudden increase in floaters
- A shadow or curtain appearing over part of the vision
Patients should bring up any gradual changes in vision, persistent discomfort, or difficulty using prescribed eye drops at their next follow-up visit. If vision seems to worsen between scheduled appointments, it is better to contact the retina specialist sooner rather than wait. Early detection of complications like steroid-induced pressure elevation leads to better outcomes.
Questions and Answers
The duration depends on the type of steroid used. A single triamcinolone acetonide injection typically provides benefit for about one to three months. The Ozurdex (dexamethasone) implant releases medication over approximately four to six months. The Iluvien (fluocinolone acetonide) implant can provide continuous drug release for two to three years. A retina specialist will recommend the formulation that best fits the patient's condition and treatment history.
Intravitreal steroid injections are designed to protect and improve vision by reducing inflammation and swelling. However, all medical procedures carry some risk. The most common side effects, elevated eye pressure and cataract formation, are manageable in most cases. Serious complications like infection are rare. A retina specialist weighs the risks and benefits for each individual patient before recommending treatment.
Yes. In some cases, a retina specialist may use both steroid and anti-VEGF injections as part of a comprehensive treatment plan. For example, a patient with diabetic macular edema who has not fully responded to anti-VEGF agents such as Eylea (aflibercept) or Vabysmo (faricimab) may benefit from adding a steroid injection or implant. The two types of medication target different aspects of the disease process and can work together.
The eye is numbed before the injection, so most patients feel pressure rather than sharp pain. Some patients report mild stinging from the antiseptic solution or brief discomfort as the needle enters the eye. After the numbing wears off, the eye may feel sore or scratchy for a few hours. Significant pain after the procedure is not normal and should prompt a call to the retina specialist.
If eye pressure rises after a steroid injection, the retina specialist will typically prescribe one or more eye drops to lower the pressure. In most patients, a single glaucoma drop is enough to bring the pressure back to a safe level. The pressure elevation is usually temporary and resolves as the steroid effect wears off. In rare cases where drops are not sufficient, a minor procedure may be needed to reduce the pressure and protect the optic nerve.