Eye Concerns

FAQ About CMV Retinitis

What is CMV?: CMV stands for Cytomegalovirus. This virus is a common source of infection in humans and generally lays dormant in the body without producing symptoms. However, in persons with a weakened immune system, such as persons with AIDS or those who have undergone organ transplantation, CMV can produce symptoms of active disease. CMV infection can occur in several parts of the body, most commonly in the gastrointestinal system and the retina, the cells in the back of the eye necessary for vision.
What is CMV Retinitis?: When CMV attacks the cells in the retina, the condition is called CMV Retinitis. CMV Retinitis develops in 20% to 40% of patients with AIDS, making it the most common AIDS-related infection of the eye. In the early stages of CMV, you may not notice any change in vision, or you may notice "floating" particles or loss of peripheral vision. The condition often begins in one eye and then may appear in the other. If left untreated, the disease progresses and can cause serious loss of vision. CMV Retinitis is not associated with light sensitivity, pain, or redness of the eye.
What is the Vitrasert® implant?: The Vitrasert implant is a pellet of ganciclovir — one of the best drugs available to fight the CMV virus. The pellet is inserted in the eye during a short surgical procedure. The pellet is coated in such a way that the drug diffuses into the eye for a long period of time, eliminating the need for daily treatment.
How does Vitrasert work?: Ganciclovir, the drug in the Vitrasert implant, effectively slows down the multiplication of the CMV virus that destroys retinal cells. Although ganciclovir does not kill the virus, it greatly reduces the speed of its multiplication. This makes it possible for you to maintain vision for distant and near objects even though you have a diagnosis of CMV Retinitis.
How is Vitrasert different than other treatments?: Ganciclovir is a very effective drug for CMV Retinitis, but, until now, it was not possible to achieve effective levels of ganciclovir within the eye without also causing other toxic side effects. Because the Vitrasert implant is placed inside the eye, large amounts of the drug diffuse into the eye but do not enter the blood stream. In this way, the drug can inhibit the virus without causing side effects in other parts of the body.
Will implantation of Vitrasert cure my CMV Retinitis?: Implantation of the Vitrasert implant will slow down the development of CMV Retinitis, but it will not cure the condition. Continued treatment is necessary. In one study, patients who received no treatment showed progression (worsening) of the Retinitis in 15 days. The patients who received Vitrasert treatment, however, did not show progression of the Retinitis for almost seven and one-half months.
How long does the implant last and what happens after it runs out?: The implant remains active for approximately seven and one-half months. After the implant runs out, your doctor can insert another implant. Clinical studies showed that a second implant was as effective as the first.
How long does the insertion procedure take?: The actual placement of the implant takes approximately 15 minutes. The entire procedure, however, including surgery preparation time may take one hour. The procedure is performed in an outpatient facility and you are able to leave and go home with an escort as soon as your surgery has been completed and your doctor tells you that you may go.
Will I be asleep or awake during the procedure?: Your doctor will use a local anesthetic for the procedure, so you will not have to be put to sleep.
Is there any pain associated with the procedure?: Pain is not likely during or after the procedure. During the procedure the local anesthetic controls any pain, and afterwards, pain is not likely because few of the eye's nerve ending are disturbed during the surgery.
How long does it take for the Vitrasert implant to become effective after implantation?: The Vitrasert implant begins to work immediately after the implantation because the medication is in direct contact with the eye and immediately begins to diffuse within the tissues.
Will the implant affect my vision?: The implant is placed in your eye so that it is not in the line of vision, and it is very unlikely that it would block, blur or distort your vision in any way.
Will the appearance of my eye change after implantation?: Because the Vitrasert implant is small and is placed inside your eye, it will not change the appearance of your eye.
Will I be able to feel the implant in my eye?: It is highly unlikely that you will feel the implant in your eye.
What other therapies for ocular CMV should I be aware of?: Other ocular CMV treatments include: Intravenous ganciclovir (Cytovene IV) Intravenous foscavir (Foscarnet) Intravitreal injection of ganciclovir (into the side of the eye) Oral ganciclovir tablets (Cytovene) Like the Vitrasert implant, all of these treatments delay the worsening of CMV Retinitis. There is no drug available at this time that kills the virus and cures the disease.
Can I have more than one treatment at the same time?: It is possible that your doctor may prescribe treatment with intravenous ganciclovir, intravenous foscavir, or oral ganciclovir at the same time that you have the implant.
What are the risks, side effects, and complications of the Vitrasert implant in comparison with the other available treatments?: Because the Vitrasert implant treats CMV Retinitis locally, side effects in other parts of the body that are associated with intravenous ganciclovir treatment do not occur. These side effects include decreased white blood cell count and other blood cell changes that may make it necessary for your doctor to discontinue intravenous treatment. Intravenous Foscarnet is less likely to cause blood cell changes, but may have a toxic effect on the kidneys. Intravitreal injection is only rarely used because it can be dangerous. The oral form of ganciclovir (tablets) can be used to treat CMV Retinitis, but is slightly less effective than IV treatment and can cause many of the same blood cells changes.
Is the Vitrasert implant suitable for all patients with CMV Retinitis?: Clinical studies demonstrated that the Vitrasert implant delays the progression of CMV Retinitis in newly diagnosed patients who have not had any previous treatment and in patients who have had other treatments. It also works for patients who have not had their CMV Retinitis controlled by any other treatment.
What more can I do to keep CMV Retinitis under control?: It is important that you cooperate with your doctor and stay as informed as possible about your medical treatment. Good communication will help your doctor manage this condition and prevent premature loss of vision.