Sustained-Release Implants for Retinal Disease

Ozurdex delivers dexamethasone, a corticosteroid that reduces inflammation, using a biodegradable polymer system. The implant releases medication in two phases: higher concentrations during the first several weeks, followed by lower, sustained levels over the remaining months. This pattern is effective for conditions where quickly controlling inflammation and then maintaining that control over time is important. Clinical trials demonstrated significant improvements in vision and reductions in macular swelling (fluid buildup in the central retina) across its approved conditions. Ozurdex was first approved for macular edema related to retinal vein occlusion and later received approval for noninfectious posterior uveitis and diabetic macular edema.

Iluvien delivers fluocinolone acetonide, a corticosteroid, at a very low but continuous dose for approximately 36 months from a single implant. This makes it the longest-acting sustained-release implant currently approved. Clinical trials known as the FAME trials showed meaningful vision improvement in patients with chronic diabetic macular edema. In early 2025, Iluvien also received an expanded FDA approval for chronic noninfectious posterior uveitis.

Because Iluvien delivers a corticosteroid over a prolonged period, the risk of cataract formation is a meaningful consideration. A substantial proportion of patients with natural lenses developed cataracts in clinical studies, which is why careful patient selection is essential. Patients who have already undergone cataract surgery are not at risk for this particular side effect, since their natural lens has already been replaced.

Susvimo is a refillable implant system originally approved for neovascular (wet) age-related macular degeneration (AMD), a condition in which abnormal blood vessels grow beneath the retina and leak fluid that damages central vision. Trial data showed that patients receiving refills every six months achieved vision outcomes comparable to those receiving monthly injections. In early 2025, the FDA approved Susvimo for center-involved diabetic macular edema and for diabetic retinopathy, based on trial results showing that the large majority of patients with the implant did not require supplemental injections over a two-year follow-up period.

Ozurdex is typically replaced every four to six months as the biodegradable polymer dissolves and the medication supply is exhausted. Iluvien provides medication for approximately 36 months from a single implant, though retreatment may be needed once that supply runs out. The Port Delivery System with ranibizumab is refilled approximately every six months. Your retina specialist will determine your individual schedule based on imaging findings, eye pressure measurements, visual acuity assessments, and your overall treatment response.

Standard anti-VEGF injections for conditions like wet AMD or DME are often given monthly or every six to eight weeks, which can mean six to twelve or more injection visits per year. By comparison, sustained-release implants substantially reduce this number.

• Ozurdex typically requires approximately two to three treatments per year
• Iluvien may require retreatment only once every three years from a single implant
• The Port Delivery System requires office refills approximately twice per year

For patients who face challenges with frequent travel, demanding schedules, or anxiety around repeated procedures, this reduction in visit frequency can meaningfully improve daily life and long-term treatment adherence.

Many retinal conditions are chronic and require ongoing management for years or even decades. Sustained-release implants fit naturally into a long-term treatment strategy, but they are rarely the final word on a patient's care plan. Your retina specialist will reassess your needs at each visit and adjust the approach if your condition changes, if a side effect develops, or if a new or better-suited treatment becomes available. Staying engaged with your care team and attending scheduled monitoring visits are essential parts of successful long-term management.

It depends on the type. Biodegradable implants like Ozurdex dissolve completely inside the eye, so removal is never needed. Non-biodegradable implants like Iluvien remain in the eye after the medication runs out, but they are extremely small and typically do not cause discomfort or require removal. The Port Delivery System is designed to stay in the eye long-term and is refilled rather than replaced. Surgical removal of any implant may be necessary in rare cases where a complication occurs, but this is uncommon in standard practice.

Yes, and this is an important expectation to set before starting implant therapy. While implants reduce the number of injection procedures needed, your retina specialist still needs to check eye pressure, evaluate your retina with imaging, and determine when the next refill or retreatment is due. Skipping monitoring visits can allow complications to go undetected. Think of the implant as reducing your procedure frequency rather than eliminating your need for ongoing evaluation and follow-up care.

For many patients, the answer may be yes. Clinical data for the Port Delivery System showed that the large majority of patients did not require supplemental injections over a two-year study period. However, individual responses vary, and some patients may still need additional treatments between scheduled refills. Your retina specialist will assess whether an implant can adequately manage your condition on its own, and that evaluation continues at every monitoring visit as your disease evolves over time.

Having glaucoma or a history of steroid-related pressure elevation does not automatically disqualify you from corticosteroid implants, but it does require very careful evaluation and especially close monitoring throughout treatment. In some situations, your retina specialist may recommend the Port Delivery System or standard anti-VEGF injections instead, since those approaches do not carry the same pressure-raising risk. Sharing your complete eye health history with your care team is essential so that the safest and most effective option can be identified for your individual situation.

Your retina specialist will use OCT imaging at follow-up visits to measure retinal thickness and detect fluid, both of which are reliable, objective markers of treatment response. Visual acuity testing and eye pressure measurements are also part of each routine monitoring visit. If imaging shows that the implant is not adequately controlling your condition, your specialist may recommend a supplemental injection, an earlier retreatment, or a transition to a different therapy. You do not need to rely solely on your own perception of vision to know how the treatment is performing, since imaging provides objective data that guides clinical decisions.

Your treatment plan can always be adjusted. Biodegradable implants like Ozurdex dissolve on their own, leaving nothing behind once the medication cycle is complete. Non-biodegradable implants like Iluvien remain in the eye but do not prevent other treatments from being used alongside them. If your condition changes and a different medication becomes more appropriate, your retina specialist can introduce that treatment in addition to, or in place of, the current implant approach. No implant therapy permanently locks you into a single treatment path.