Risks and Side Effects of Eye Injections for Diabetes
Types of Eye Injections Used for Diabetic Eye Disease
Anti-VEGF medications block a protein that causes abnormal blood vessels to grow and leak in your retina. We use these injections to treat diabetic macular edema and diabetic retinopathy. They are the most common type of injection for diabetic eye disease. Avastin (bevacizumab) is commonly used off-label for diabetic eye disease in many practices.
These medications help reduce swelling and prevent vision loss. Treatment is often monthly at first, then adjusted based on your response, sometimes extending longer than eight weeks.
Steroid medications reduce inflammation and swelling in the retina. Ozurdex and Iluvien are intravitreal implants that release medication over time, while Triesence is an injected steroid. Some steroid implants can last several months, reducing the number of treatments you need. Iluvien is typically considered in select patients with diabetic macular edema and requires careful eye pressure monitoring.
Steroids work differently than anti-VEGF medications and can be very effective for certain patients. However, they carry different risks, especially related to eye pressure and cataracts.
- Sustained eye pressure rise and glaucoma risk
- Cataract progression over time
- Need for more frequent pressure checks during treatment
- Implant migration in certain eye conditions
Anti-VEGF and steroid injections affect your eye in different ways, which means they have different side effects. Anti-VEGF injections rarely raise eye pressure and do not increase cataract risk. Steroid injections, on the other hand, can raise eye pressure in some patients and may speed up cataract formation.
Our eye doctor will consider your medical history, current eye health, and previous responses to treatment when choosing the best medication for you. We monitor you closely for side effects specific to the type of injection you receive.
Common and Expected Side Effects
Many patients feel mild discomfort or a scratchy sensation after their injection. This happens because the injection can irritate the surface of your eye. The feeling is usually mild and goes away within a day or two.
- The sensation may feel like an eyelash or grain of sand in your eye
- Artificial tears can help soothe irritation
- Avoid rubbing your eye, which can worsen discomfort
- Contact us if the irritation gets worse or lasts more than a few days
You may notice small dark spots, strings, or bubbles floating in your vision after your injection. These floaters are usually caused by tiny air bubbles or the medication itself in the vitreous gel inside your eye. They typically fade or settle within a few days.
While floaters after injection are common and expected, a sudden shower of new floaters or a curtain across your vision is not normal. If you notice these changes, contact us right away, as they may signal a more serious problem.
A bright red patch on the white of your eye is very common after an injection. This subconjunctival hemorrhage happens when a small blood vessel breaks during the procedure. It looks alarming but is usually harmless and does not affect your vision.
- The red patch may spread or become darker in the first day or two
- It usually clears up on its own within one to three weeks
- No treatment is needed for this type of bleeding
- Call us if you have significant pain, pus-like discharge, or vision decline
Blurry vision right after your injection is normal and expected. The medication, any drops used during the procedure, and the numbing process can all temporarily blur your sight. Most patients notice their vision clearing over several hours.
Your eyes may also be more sensitive to bright light for a day or two. Wearing sunglasses when you go outside can help. If your vision does not start to improve within 24 hours or gets significantly worse, call our office.
Your eye pressure may rise slightly after an injection because we are adding fluid to a closed space inside your eye. This increase is usually temporary and mild. We may check your eye pressure before you leave, especially if you have glaucoma, advanced optic nerve damage, symptoms, or are receiving steroid treatment.
- Most patients do not feel any symptoms from mild pressure changes
- The pressure typically returns to normal within hours or days
- Patients on steroid injections need closer monitoring for pressure issues
- Severe eye ache, headache, nausea, or seeing halos requires same-day contact
Serious Complications and Warning Signs
Endophthalmitis is a very rare but serious infection inside the eye. It can occur when bacteria enter the eye during or after the procedure. We take many precautions to prevent infection, but it remains the most serious risk of eye injections.
Symptoms of infection can occur within days, sometimes sooner, after your injection and may include severe eye pain, worsening vision, increased redness, sensitivity to light, and discharge. If you have any of these symptoms, you need to be seen immediately, as early treatment is critical to saving your vision.
Retinal detachment is an extremely rare complication of eye injections. Symptoms include a sudden increase in floaters, flashes of light, or a dark curtain or shadow covering part of your vision. These symptoms require emergency evaluation.
- Retinal detachment can occur hours to days after an injection
- People with proliferative diabetic retinopathy may be at higher risk for tractional detachment
- Immediate treatment is necessary to prevent permanent vision loss
- Call us or go to an emergency room if you notice these warning signs
While mild pressure increases are common and temporary, some patients develop sustained high eye pressure after injections. This is more common with steroid injections. High pressure over time can damage the optic nerve and cause glaucoma.
We monitor your eye pressure at every visit and may check it more frequently if you are receiving steroid injections. If your pressure stays high, we may prescribe pressure-lowering eye drops or recommend a different medication.
Mild surface irritation is common after an injection. Significant intraocular inflammation is uncommon and should prompt evaluation. Symptoms include increased eye pain, redness, blurred vision, and light sensitivity that worsens instead of improving.
Inflammation usually responds well to anti-inflammatory eye drops. We check for signs of inflammation at your follow-up visits and will adjust your treatment if needed.
- Call urgently if pain is worsening rather than improving
- Call urgently if your vision is decreasing
- Call urgently if redness or light sensitivity is increasing
- Call urgently if you develop new discharge from your eye
In proliferative diabetic retinopathy, fragile blood vessels can bleed spontaneously. Bleeding can also occur around the time of injection due to underlying disease activity, traction, or rarely procedure-related factors. You may notice a sudden cloud of dark floaters or a red tint to your vision. Small vitreous hemorrhages often clear on their own, while larger bleeds may require additional treatment.
Any sudden dense vision loss warrants urgent evaluation to rule out retinal tear, retinal detachment, or significant hemorrhage. Sleeping with your head elevated can help blood settle, and most small bleeds clear within a few weeks. We will monitor the bleeding and your vision closely.
Rarely, the injection procedure can cause injury to the cornea, lens, or retina. Corneal abrasion can occur from the antiseptic solution or the instrument used to hold your eyelids open. Lens injury and retinal tears are extremely uncommon but possible.
- Severe scratchy pain or inability to open your eye may indicate corneal abrasion
- Marked sensitivity to light that does not improve within hours
- Sudden new floaters or flashes of light may signal a retinal tear
- Sudden blur that does not improve requires urgent evaluation
- Call us right away if you experience any of these symptoms
Possible Systemic Side Effects from Anti-VEGF Treatment
Anti-VEGF medications are injected into your eye, but a small amount can enter your bloodstream. Rare reports have linked these medications to an increased risk of stroke, heart attack, and blood pressure changes, especially in patients with diabetes who may already have cardiovascular risk factors. The evidence is mixed, and these events are very uncommon.
Seek emergency care immediately if you develop sudden numbness or weakness on one side of your body, difficulty speaking, severe chest pain, shortness of breath, or sudden severe headache. While these symptoms are unlikely to be related to your eye injection, they require urgent medical evaluation.
What Happens During and After Your Injection Appointment
Preventing infection is our top priority. We use a sterile technique for every injection, which includes cleaning the surface of your eye with an antiseptic solution. The antiseptic on the eye surface is the most important infection-prevention step. Antibiotics are not always prescribed, but if we prescribe them, use them as directed.
- We work in a clean procedure room using sterile instruments
- The skin around your eye is cleaned thoroughly
- A sterile drape may be placed around your eye
- We minimize contact with your eyelids and lashes during the procedure
We numb your eye with special drops so you should not feel pain during the injection. You may feel pressure or a slight pinch, but most patients report that the injection is less uncomfortable than they expected. The actual injection takes only a few seconds.
You will need to keep your eye still and look in the direction we tell you. We may use a small instrument to hold your eyelids open. Try to relax and breathe normally, which makes the process easier for both you and our eye doctor.
Your vision will be blurry when you leave, and your eye may feel scratchy or irritated. We recommend having someone drive you home because your vision may not be clear enough to drive safely. Your eye may water or produce some clear discharge, which is normal.
Plan to take it easy for the rest of the day. You can return to most normal activities, but avoid strenuous exercise and swimming. Use your prescribed eye drops as directed and keep your hands away from your eye.
Most side effects improve significantly within the first few days. Your vision should clear within 24 hours, though it may take a few days to reach its best level. Any redness, irritation, or floaters typically fade during the first week.
- Day one: Expect blurry vision, mild discomfort, possible redness
- Days two to three: Vision clears, discomfort decreases
- Days four to seven: Most minor side effects have resolved
- Contact us if symptoms worsen or do not improve on this timeline
We will schedule a follow-up visit to check your eye pressure, look for signs of infection or inflammation, and see how your eye is responding to treatment. For some patients, this visit happens within a few days, while others return in four to eight weeks.
Your follow-up schedule depends on the type of injection you received, your eye condition, and your individual response to treatment. Keep all scheduled appointments so we can monitor your progress and adjust your treatment plan if needed.
Other Treatment Options and Adjuncts for Diabetic Eye Disease
Eye injections are one of several treatments for diabetic eye disease. Laser treatment, including focal or grid laser for diabetic macular edema and panretinal photocoagulation for proliferative diabetic retinopathy, may be recommended alone or with injections. Vitrectomy surgery may be needed for nonclearing vitreous hemorrhage or tractional retinal detachment.
In some stable cases, observation with close monitoring may be appropriate. Our eye doctor will discuss which treatments are best for your specific condition and how they may work together to preserve your vision.
Controlling your blood sugar, blood pressure, and cholesterol is the foundation of managing diabetic eye disease. Good systemic control can slow the progression of retinopathy and improve your response to injections and other treatments.
- Work with your primary care doctor or endocrinologist to optimize your A1c
- Keep your blood pressure in a healthy range
- Manage cholesterol and other cardiovascular risk factors
- Systemic control complements eye treatments and may reduce the need for frequent injections
How to Lower Your Risk of Side Effects
Some medications can increase your risk of bleeding or affect how well your eye heals. Tell us about all prescription drugs, over-the-counter medicines, vitamins, and supplements you take. Blood thinners are especially important to mention, though you should not stop taking them without asking the doctor who prescribed them.
Let us know if you have ever had an allergic reaction to any medication, eye drop, or antiseptic. We can adjust our procedure to avoid substances that might cause a reaction.
Good blood sugar control helps your eye heal better and may improve your response to treatment. High blood sugar can weaken your immune system and slow healing. Do your best to keep your blood sugar in your target range in the days leading up to your injection.
- Take your diabetes medications as prescribed
- Eat a healthy meal before your appointment
- Check your blood sugar regularly
- Tell us if your blood sugar has been running higher than usual
If we prescribe drops, sometimes antibiotic or anti-inflammatory, use them exactly as directed. Many patients do not need post-injection antibiotics depending on our clinic protocol and your individual risk factors. When prescribed, these drops help prevent infection and reduce inflammation. Missing doses or stopping the drops too early can increase your risk of complications.
Wash your hands before putting in drops, and do not let the tip of the bottle touch your eye or any surface. If you are using multiple types of drops, wait at least five minutes between each medication.
Touching or rubbing your eye can introduce bacteria and increase the risk of infection. It can also irritate the injection site and delay healing. If your eye itches or feels uncomfortable, use preservative-free artificial tears instead of rubbing.
- Wash your hands frequently, especially before touching your face
- Do not apply eye makeup for at least 24 hours after your injection
- Avoid getting soap or shampoo in your eye when washing your face or hair
- Use a clean towel and do not share towels or washcloths with others
For the first 24 to 48 hours after your injection, avoid activities that could expose your eye to bacteria or cause trauma. Do not swim in pools, hot tubs, or natural bodies of water. Skip contact sports and heavy lifting that causes straining.
You can shower and wash your face carefully, but keep your eyes closed and avoid direct water spray. You may watch television, use a computer, and read as long as your vision allows. Most normal daily activities are safe after the first day or two.
When to Call Us or Seek Emergency Care
Some symptoms require immediate medical attention, even in the first hours after your injection. Severe eye pain that does not improve with over-the-counter pain relievers is not normal. A sudden, significant decrease in vision or complete loss of vision is an emergency. Seek emergency care at a facility that can contact an on-call ophthalmologist or retina specialist when severe symptoms occur.
- Severe pain that keeps getting worse
- Vision that becomes much worse instead of improving
- A feeling that something is very wrong with your eye
- Call our office immediately or go to an emergency room
Infection symptoms can occur within days, sometimes sooner, after an injection. Watch for increased pain, especially if it is getting worse rather than better. Worsening redness, increasing discharge, new light sensitivity, and progressive vision loss are all warning signs.
If you develop a fever along with eye symptoms, this increases the concern for infection. Do not wait to see if these symptoms improve on their own. Contact us right away, day or night, if you suspect an infection.
While some blurriness is normal right after an injection, certain vision changes need urgent evaluation. A sudden shower of new floaters, flashing lights, or a dark curtain or shadow blocking part of your vision may indicate retinal detachment.
If you see a sudden increase in floaters that looks like a swarm of gnats or cobwebs, call us immediately. Vision changes that come on suddenly and severely are more concerning than gradual changes.
Mild discomfort and a scratchy feeling are normal after an injection, but significant pain is not. Pain that gets worse over time, pain that wakes you from sleep, or pain that does not respond to over-the-counter pain medication should be evaluated.
- Mild discomfort should improve over the first one to two days
- Moderate to severe pain needs same-day evaluation
- Pain accompanied by vision loss or discharge is more concerning
- Call us rather than waiting to see if pain improves on its own
Frequently Asked Questions
Serious complications are very rare. Endophthalmitis, the most serious risk, is extremely uncommon. Retinal detachment is even rarer. The benefits of preserving your vision usually far outweigh these small risks, especially when diabetic eye disease threatens your sight.
We discuss risks and benefits with every patient before starting treatment. Our goal is to help you make an informed decision about your eye care.
If you experience mild, expected side effects like temporary blurriness or a bloodshot eye, treatment usually continues because these do not cause lasting harm. If you develop a serious complication, we will discuss whether to continue, switch medications, or try a different treatment approach. Many patients tolerate injections well even after minor side effects from previous treatments.
We monitor you closely at every visit and will adjust your plan if side effects become a concern.
Steroid and anti-VEGF injections have different risk profiles rather than one being universally riskier. Steroids are more likely to raise eye pressure and accelerate cataract growth, especially with repeat injections. Anti-VEGF medications rarely cause these problems but may need more frequent dosing. We choose the medication that best matches your specific eye condition and overall health.
Your individual medical history and eye health help us decide which treatment is safest and most effective for you.
We strongly recommend arranging a driver because your vision will be blurry after the injection. The numbing drops, antiseptic solution, and the medication itself can make it unsafe to drive. Your vision may also be affected by dilation if used, and individual responses vary. Plan to have someone bring you to and from your appointment, or use a taxi or ride service.
Most patients find their vision clears enough to resume driving the next day, but plan for limited vision immediately after your appointment.
One complication does not mean you will have another, especially if the first one was treated successfully. We will review what happened and may adjust our technique, prescribe additional preventive medications, or monitor you more closely. In some cases, switching to a different type of injection or exploring alternative treatments may be appropriate.
Let us know about any past problems so we can take extra precautions and answer your concerns before your next treatment.
Each injection carries the same small risk of infection or other acute complications, so having more injections means more opportunities for a problem to occur. However, cumulative risks like cataract formation or chronic high eye pressure are more related to steroid injections than anti-VEGF injections. We monitor your eyes at every visit and watch for any signs of cumulative effects from long-term treatment.
Long-term treatment with anti-VEGF injections is common and generally well tolerated when monitored appropriately.
Getting Help for Risks and Side Effects of Eye Injections for Diabetes
If you have questions or concerns about side effects from your eye injection, our office is here to help. We want you to feel confident about your treatment and know when to reach out for assistance. Do not hesitate to call us if you are unsure whether a symptom is normal, especially in the first week after your injection.