Wet Macular Degeneration Intravitreal Injection

Treating Wet AMD Choroidal Neovascularization with Lucentis, Avastin

Nov 17, 2009 Sharon Perkins

Wet macular degeneration(AMD) affects millions of people in the US. Many are treated with intravitreal injections; medication is injected into the eye with a thin needle.

The macula is the center of clear sharp vision in the eye. Age related macular degeneration occurs when cells in the macula begin to break down. There are two types of AMD, dry and wet, with wet being the more serious. In wet AMD, abnormal blood vessels form beneath the macula, a process called choroidal neovascularization.These abnormal blood vessel leak, causing swelling and fluid beneath the macula.

Treating Macular Degeneration with Intravitreal Injections of Lucentis, Avastin

Intravitreal injection with one of two anti-VEGF medications, Lucentis or Avastin, into the intravitreal space through the sclera, the white part of the eyeball, is the treatment of choice for AMD in 2009. VEGF, or vascular endotheliel growth factor, is responsible for growth of the fragile new blood vessels. Lucentis (ranibizumab) is a drug specifically developed for treatment of wet macular degeneration by the pharmaceutical company Novartis. Lucentis is FDA approved for use in the eye.

Avastin (bevacizumab) is an anti-VEGF medication which is used to treat cancer. Retinal specialists began using Avastin when clinical trials were being done on Lucentis, because the two drugs are chemically very similar and the results for Lucentis were so promising, but was only available to people enrolled in the trials.

Avastin is an FDA approved drug, but hasn’t undergone formal testing for ocular use, so its use is said to be “off label.” Avastin is considerably cheaper than Lucentis, because Lucentis is sold only in single dose vials. Avastin vials are larger and can be divided into many doses in a pharmacy.

Most insurance, including Medicare, now cover Lucentis for wet, or exudative, AMD. Some practitioners still use Avastin, which is also covered for wet AMD by Medicare, either because their patients have had a good response and they see no reason to change or because their patient insurance doesn’t cover the cost. Because there are differences between the two drugs, more study over which should be the drug of choice is required, as discussed in the article “Treatment of Exudative Age-related Macular Degeneration: Many Factors to Consider” published in American Journal of Ophthalmology in 2008.

How Intravitreal Injections are Done; Prepping the Eye and Injecting

Patients receiving an intravitreal injection have their eye prepped first, usually by a technician, in the following way, although practitioners may vary slightly:

• The technician first applies a numbing agent, usually a clear drop called proparacaine.
• An antibiotic drop is applied.
• Povidone iodine is administered to sterilize the eye.
• Another numbing agent, such as lidocaine jelly or tetravisc is applied.

The doctor may hold the eye open with a metal speculum, or he or a technician may hold the eye open. The injection itself is very quick, taking 30 seconds or less. Another antibiotic drop may be given, along with a prescription to continue antibiotic drops for several days.

Side Effects of Lucentis or Avastin to Treat Choroidal Neovascularization

The most common side effect after intravitreal injection is irritation, a feeling like something is in the eye. Artificial tears can greatly reduce the discomfort and can be applied frequently. There may be a cherry red spot on the eye if the needle punctured a small blood vessel; doctors can’t see these tiny vessels when they inject the medication.

Floaters are very common, and usually clear up within a few days. A scratch on the surface of the eye, called a corneal abrasion, can cause severe pain, but usually heals within a day. Corneal abrasions may result from the patient rubbing the numbed eye after the injection. A doctor should be seen; the eye may be patched after ointment is applied.

Serious Complications of Anti VEGF Macular Degeneration Treatments

Serious complications can occur after intravitreal injection. An infection in the eye called endophthalmitis can threaten vision and needs prompt treatment. An eye that’s red beyond the small spot a broken blood vessel might cause, bulging, extremely painful, and/or sudden vision loss should send the patient to the phone to call the doctor immediately.

Retinal detachment can occur after injection, so patients with floaters that worsen after the injection should also be seen promptly. These serious side effects are rare, occurring in fewer than .05% of cases, according to a study reported in Eye in 2008.

Lucentis and Avastin Help Decrease Vision Loss

Anti VEGF medications help keep wet AMD from worsening. Treatments need to be done every month or so when treatment is initiated, and gradually tapered off. Anti VEGF medications aren’t a cure for AMD, but rather a way to minimize the vision loss over time.

Sources:

Am J Ophthalmol, Treatment of Exudative Age-related Macular Degeneration: Many Factors to Consider; Timothy Olsen, MD; August 2007

Eye, Short Term Complications of Intravitreal Injections of Triamciolone and Bevacizumab; JB Jonas, UH Spandau, F Schlitenbrede, Feb. 22, 2008

The copyright of the article Wet Macular Degeneration Intravitreal Injection in General Medicine is owned by Sharon Perkins. Permission to republish Wet Macular Degeneration Intravitreal Injection in print or online must be granted by the author in writing.

Intravitreal Injections are the Treatment for AMD

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