Intravitreal Injections
Intravitreal Medication injections
In some cases, medication may be used to help treat diabetic retinopathy. Sometimes a steroid medication is used. In other cases, you may be given an anti-VEGF medication. This medication works by blocking a substance known as vascular endothelial growth factor, or VEGF. This substance contributes to abnormal blood vessel growth in the eye which can affect your vision. An anti-VEGF drug can help reduce the growth of these abnormal blood vessels.
After your pupil is dilated and your eye is numbed with anesthesia, the medication is injected into the vitreous, or jelly-like substance in the back chamber of the eye. The medication reduces the swelling, leakage, and growth of unwanted blood vessel growth in the retina, and may improve how well you see.
Medication treatments may be given once or as a series of injections at regular intervals, usually around every four to six weeks or as determined by your doctor.
Bilateral simultaneous intra-vitreal injections in few seconds
Lucentis vs Avastin
The value of safety
A new study by Dr. Sanjay Sharma at Queen’s University in Kingston Ontario looked at the relative safety of Lucentis (retail price $1700) and Avastin (retail price $100) – two drugs used to treat wet macular degeneration (AMD). The results could influence current health policy trends.
Steroids IVIs
OZURDEX® (dexamethasone intravitreal implant)
A prescription medicine that is an implant injected into the eye (vitreous) and used: •To treat adults with swelling of the macula (macular edema) following branch retinal vein occlusion (BRVO) or central retinal vein occlusion (CRVO) •To treat adults with noninfectious inflammation of the uvea (uveitis) affecting the back segment of the eye
Intravitreal injections of triamcinolone acetate
(Kenalog) Off-label use
Intravitreal injections of triamcinolone acetate (Kenalog) have become increasingly popular for treating a broad spectrum of retinal diseases. Risks of intravitreal Kenalog injections, such as IOP elevation, cataract and infection, must be weighed against the potential benefits. Indications We use intravitreal Kenalog injections to treat the following:
- pseudophakic cystoid macular edema that fails to respond to conventional therapy;
- clinically significant diffuse diabetic macular edema that fails to respond to conventional laser treatment;
- macular edema associated with branch retinal vein occlusion that fails to respond to laser treatment (or where laser has not been shown to be useful);
- nonischemic central retinal vein occlusions associated with decreased vision with or without macular edema; and
- select cases of wet AMD, often in combination with photodynamic therapy with verteporfin (Visudyne).
The efficacy of Kenalog on vascular permeability and new vessel growth may involve multiple mechanisms, including reduced tight junction permeability and downregulation of the effects of vascular endothelial growth factor.
(TRIESENCE®) on-label use
At PVSC, We use the TRIESENCE® (triamcinolone acetonide) Injectable Suspension 40 mg/mL. It is made for the eye, which decreases the chances of side effects, like inflammation.
Risks
Any intraocular injection carries the risk of vision loss from infection, retinal detachment or hemorrhage. Potential risks of intravitreal Kenalog injections include the following:
IOP rise.
A number of researchers have noted Kenalog-induced increases in IOP, with the reported incidence as high as 50 percent.7 Fortunately, when this occurs, one topical glaucoma drop alone is adequate for the management in most cases. Patients with a history of glaucoma are at higher risk due to the higher incidence of “steroid responders” in this patient population. Approximately 1 percent of patients with a pressure rise can develop intractable glaucoma requiring trabeculectomy or a glaucoma drainage device, particularly in cases of central retinal vein occlusion. We avoid injecting steroids in those patients who are already on two or more glaucoma drops.
Cataract.
Cataracts may occur from direct contact with the lens either during the intravitreal injection or during an anterior chamber paracentesis performed for elevated IOP. We have not personally observed this complication, but it is possible. More commonly, progressive or new posterior subcapsular cataract is observed following Kenalog injections due to the glucocorticoid effects of the drug itself. It is thought that multiple Kenalog injections are required for the development or progression of cataract but a single injection in susceptible patients may increase or cause cataract. Since cataract surgery may be required to rehabilitate vision, it should be kept in mind that inflammation related to the surgery may aggravate retinal edema and vasoproliferation.
Endophthalmitis.
Endophthalmitis following intravitreal Kenalog injections is rare, with an incidence of 1 in 500 to 1 in 1,000. Included among these are cases of pseudoendophthalmitis or sterile endophthalmitis, which are likely the result of an inflammatory response to a preservative in the Kenalog formulation. Concentrating the Kenalog crystals and removing the supernatant may reduce the risk of an inflammatory response. Sterile and infectious endophthalmitis can be differentiated in part by the time of onset of signs and symptoms. In the cases of sterile endophthalmitis the onset is typically one to two days following injection; in contrast, symptoms of infectious endophthalmitis typically begin four to 14 days following injection. The steroid itself may suppress the inflammation and pain associated with cases of infectious endophthalmitis, which may complicate making the diagnosis.
Vitreous hemorrhage.
We have had a few cases of vitreous hemorrhage following Kenalog injections. In each instance, the patient was on anticoagulant therapy; the most severe cases were associated with the use of clopidogrel bisulfate (Plavix). Vitrectomy was required in some cases to clear the persistent hemorrhage, which was dense enough to cause count fingers or hand motion vision. Patients taking warfarin seem less prone to hemorrhage, although a randomized study of sufficient size would be required to assess the risk of anticoagulant therapy.
EYLEA® (aflibercept) Injection
Indicated for the treatment of patients with neovascular (Wet) Age-related Macular Degeneration (AMD). Indicated for the treatment of patients with Macular Edema following Central Retinal Vein Occlusion (CRVO). EYLEA is contraindicated in patients with ocular or periocular infections, active intraocular inflammation, or known hypersensitivity to aflibercept or to any of the excipients in EYLEA.
JETREA® (ocriplasmin)
JETREA® (ocriplasmin) Intravitreal Injection, 2.5 mg/mL, is a proteolytic enzyme indicated for the treatment of symptomatic vitreomacular adhesion. The FIRST and ONLY FDA-approved medicine for symptomatic Vitreomacular Adhesion (VMA).
Important Safety Information
Warnings and Precautions
- A decrease of ≥ 3 lines of best-corrected visual acuity (BCVA) was experienced by 5.6% of patients treated with JETREA and 3.2% of patients treated with vehicle in the controlled trials. The majority of these decreases in vision were due to progression of the condition with traction and many required surgical intervention. Patients should be monitored appropriately.
- Intravitreal injections are associated with intraocular inflammation/infection, intraocular hemorrhage and increased intraocular pressure (IOP). Patients should be monitored and instructed to report any symptoms without delay. In the controlled trials, intraocular inflammation occurred in 7.1% of patients injected with JETREA vs 3.7% of patients injected with vehicle. Most of the post-injection intraocular inflammation events were mild and transient. If the contralateral eye requires treatment with JETREA, it is not recommended within 7 days of the initial injection in order to monitor the post-injection course in the injected eye.
- Potential for lens subluxation.
- In the controlled trials, the incidence of retinal detachment was 0.9% in the JETREA group and 1.6% in the vehicle group, while the incidence of retinal tear (without detachment) was 1.1% in the JETREA group and 2.7% in the vehicle group. Most of these events occurred during or after vitrectomy in both groups.
- Dyschromatopsia (generally described as yellowish vision) was reported in 2% of all patients injected with JETREA. In approximately half of these dyschromatopsia cases there were also electroretinographic (ERG) changes reported (a- and b-wave amplitude decrease).
Adverse Reactions
- The most commonly reported reactions (≥ 5%) in patients treated with JETREA were vitreous floaters, conjunctival hemorrhage, eye pain, photopsia, blurred vision, macular hole, reduced visual acuity, visual impairment, and retinal edema.