Cytomegalovirus retinitis

BACKGROUND

Cytomegalovirus (CMV) is a common viral infection that is related to herpes. Like many other herpes viruses, CMV remains latent in healthy hosts, which means the virus remains dormant inside the individual. Even though the virus is present, no signs or symptoms of illness appear during this stage. However, if diseases, transplants or chemotherapy compromise the host's immune system, the CMV may reactivate, causing the individual to become ill.

HIV positive individuals are at the greatest risk for CMV, especially when their CD4 cell count decreases. CMV retinitis (inflammation of the retina) is a leading cause of blindness in patients with AIDS. It is also increasingly common among organ transplant recipients, as the number of those procedures performed each year increases.

CMV infects between 50-80% of the adult population. Clinically evident disease is found almost exclusively in individuals who are immunocompromised.

CAUSES

CMV is present in nearly everyone. However, individuals who have compromised immune systems may not be able to adequately destroy the virus, which can lead to potentially serious eye damage.

SYMPTOMS

CMV retinitis may affect one eye at first, but usually progresses to both eyes, and symptoms worsen as the patient's ability to fight off the infection decreases. In about 30% of cases, there is evidence of retina damage.

Common symptoms include: floaters (seeing spots or spider webs), light flashes, blind spots, blurred vision, obstructed areas of vision, photophobia (abnormal sensitivity to light) and sudden decrease of vision.

The condition usually requires the expertise of a vitreo-retinal surgeon. Patients with CMV retinitis are at risk of retinal detachment, hemorrhages and inflammation of the retina, which can lead to permanent vision loss or blindness.

PREGNANCY

A pregnant mother with CMV can potentially pass the virus to her fetus, which increases the risk of birth defects. CMV is the most common congenital infection. The majority of babies who are infected with the virus before birth are asymptomatic (experience no symptoms) at birth. However, up to 15% will develop neurological abnormalities like deafness, blindness or mental retardation, according to the Centers for Disease Control and Prevention (CDC).

Pregnant women undergo a blood test to determine whether or not they have CMV. If the pregnant woman tests positive, the physician may test the fetus for infection with amniocentesis.

If the fetus shows signs of infection, an ultrasound can be used to detect any abnormalities in the fetus. Treatment may include an antiviral medication. However, antiviral drugs have not been proven to be safe during pregnancy. Also, there is no scientific evidence that antiviral drugs can protect the fetus from CMV.

DIAGNOSIS

A vitreo-retinal surgeon should evaluate patients who experience CMV retinitis symptoms. The surgeon will diagnose the patient after thoroughly examining the retina using an ophthalmoscope. During the procedure, the patient is given eye drops to dilate the pupils. Then the surgeon looks through the ophthalmoscope to see the retina.

A fluorescein angiogram may be necessary to evaluate the circulatory system of the retina. During the procedure, a special dye called fluorescein is injected into the patient's vein. In a few seconds, the dye travels to the blood vessels in the eye. A camera, which has special filters that highlight the dye, takes photographs of the blood vessels in the back of the eye. The pictures will show any swelling or abnormal blood vessels.

TREATMENT

CMV retinitis can potentially cause serious eye damage, often including vision loss. If left untreated, CMV will almost always cause blindness. A vitreo-retinal surgeon usually treats the virus.

Antiviral medication: Anti-viral medications (like Ganciclovir© or Foscarnet©) are often prescribed. These drugs can be administered orally, intravenously, injected directly into the eye or through an intravitreal implant (small capsules of medications surgically inserted into the eye).

INTEGRATIVE THERAPIES

Unclear or conflicting scientific evidence :

Alizarin : Limited available evidence suggests that alizarin may be useful for viral infections such as herpes. Additional study is needed before a conclusion can be made. There are few reports of adverse effects in humans associated with alizarin, including contact dermatitis, nausea, vomiting, transient weakness, loss of muscle control, sub-acute toxicity, progressive listlessness, hyperirritability, insomnia and abnormal breathing. However, alizarin may be toxic and should not be handled for long periods of time, rubbed in the eyes or eaten. Avoid if allergic to alizarin, Rubia tinctorum or other plants from the Rubiaceae family. Avoid if pregnant or breastfeeding.

Blessed thistle : Laboratory studies report no activity of blessed thistle against herpes viruses, influenza or poliovirus. Effects of blessed thistle (or chemicals in blessed thistle called lignans) against HIV are not clear. Human research of blessed thistle as a treatment for viral infections is lacking. Blessed thistle is generally considered to be safe when taken by mouth in recommended doses for short periods of time, with few reported side effects such as birth defects, bleeding, breathing problems, bruising, cancer of the nose or throat, increased production of stomach acid, itching, kidney disease, liver toxicity, skin rash, stomach discomfort, stomach ulcers and vomiting. Allergic reactions to blessed thistle including rash may occur, as well as cross-sensitivity to mugwort and Echinacea. Cross-reactivity may also occur with bitter weed, blanket flower, Chrysanthemum, coltsfoot, daisy, dandelion, dwarf sunflower, goldenrod, marigold, prairie sage, ragweed or other plants in the Asteraceae/Compositae family. Avoid if pregnant or breastfeeding.

Cranberry : Limited laboratory research has examined the antiviral activity of cranberry. There is currently a lack of reliable human studies in this area. Avoid if allergic to cranberries, blueberries or other plants of the Vaccinium species. Sweetened cranberry juice may affect blood sugar levels. Use cautiously with a history of kidney stones. Avoid more than the amount usually found in foods if pregnant or breastfeeding.

Sorrel : There is currently a lack of well-conducted published studies that demonstrate antiviral or antibacterial activity of sorrel. In an in vitro study, sorrel did not demonstrate activity against herpes simplex virus-1, herpes simplex virus-2, HIV, B. subtilis, E. coli, Proteus morganii, Pseudomonas aeruginosa, P. vulgaris, Serratia marcescens, or Staphylococcus aureus. Avoid with a known allergy to sorrel. Avoid large doses of sorrel because there have been reports of toxicity and death. This may be because of the oxalate found in sorrel. Be aware that many tinctures contain high levels of alcohol and should be avoided when driving or operating heavy machinery. These sorrel formulations may cause nausea or vomiting when taken with the prescription drugs metronidazole (Flagyl©) or disulfiram (Antabuse©). Avoid if pregnant or breastfeeding.

Turmeric : Early evidence suggests that turmeric may help treat viral infections. However, there is not enough human study in this area. Well-designed trials are needed to make a conclusion. Avoid if allergic or hypersensitive to turmeric, curcumin, yellow food colorings, or plants belonging to the Zingiberaceae (ginger) family. Use cautiously with a history of bleeding disorders, immune system deficiencies, liver disease, diabetes, hypoglycemia, or gallstones. Use cautiously with blood-thinners, such as warfarin (like Coumadin©), and blood sugar-altering medications. Avoid in medicinal amounts if pregnant or breastfeeding. Turmeric should be stopped prior to scheduled surgery.

Traditional or theoretical uses lacking sufficient evidence :

Astragalus : Astragalus is frequently found in herbal combinations used to treat viral infections. Antiviral effects have been demonstrated in early study, however human evidence is currently lacking. Additional research is needed in this area. Avoid if allergic to astragalus, peas, or any related plants or with a history of Quillaja bark-induced asthma. Avoid with aspirin or aspirin products or herbs or supplements with similar effects. Avoid with inflammation (swelling) or fever, stroke, transplant or autoimmune diseases (like HIV/AIDS). Stop use two weeks before surgery/dental/diagnostic procedures with a risk of bleeding and avoid use immediately after these procedures. Use cautiously with bleeding disorders, diabetes, high blood pressure, lipid disorders or kidney disorders. Use cautiously with blood-thinners, blood sugar drugs, or diuretics or herbs and supplements with similar effects. Avoid if pregnant or breastfeeding.

Chaparral : Chaparral has been shown to have antiviral activity in early research, however human studies are currently lacking. Avoid if allergic to chaparral or any of its components, including nordihydroguaiaretic acid. Use cautiously if taking blood thinners (anticoagulants), blood sugar medication, or drugs that are broken down by the liver (like amiodarone, phenobarbital, valproic acid). Stop use two weeks before surgery/dental/diagnostic procedures with bleeding risk, and do not use immediately after these procedures. Use cautiously if driving or operating heavy machinery. Avoid if pregnant or breastfeeding.

Garlic : Preliminary studies have demonstrated effects of garlic against several viruses, including influenza B virus, herpes simplex virus type 1, herpes simplex virus type 2, parainfluenza virus type 3, vaccinia virus, vesicular stomatitis virus, human rhinovirus type 2, and cytomegalovirus. Human research is needed to confirm the antiviral effects of garlic. Avoid if allergic or hypersensitive to garlic or other members of the Lilaceae (lily) family (like hyacinth, tulip, onion, leek, chive). Avoid with a history of bleeding problems, asthma, diabetes, low blood pressure, or thyroid disorders. Stop using supplemental garlic two weeks before dental/surgical/diagnostic procedures and avoid using immediately after such procedures to avoid bleeding problems. Avoid in supplemental doses if pregnant or breastfeeding.

Spirulina : Polysaccharides found in Arthrospiria platensis (formerly known as Spirulina platensis) have been shown to inhibit viruses in animal study. Human research is needed to confirm the antiviral effects of spirulina. Avoid if allergic or hypersensitive to spirulina or blue-green algae. Use cautiously with phenylketonuria (a genetic disorder of a liver enzyme that disrupts normal body functions), autoimmune diseases, bleeding disorders, diabetes, and osteoporosis. Use cautiously with products containing the blue-green algae species Anabaena spp., Aphanizomenon spp., and Microcystis spp.; in underweight patients or in those taking antiobesity agents or appetite suppressants; and if consuming a high-protein diet. Avoid in children and if pregnant or breastfeeding.

PREVENTION

To prevent CMV infection in pregnancy, wash hands with soap and water before meals and especially after changing diapers. If mononucleosis-like symptoms, such as fatigue, fever, headache, sore throat, chills or muscle aches, appear during pregnancy, consult a qualified healthcare provider.

Treating underlying disorders may help prevent the development of retinitis.

AUTHOR INFORMATION

This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

• Hodge WG, Boivin JF, Shapiro SH, et al. Iatrogenic risk factors for cytomegalovirus retinitis. Can J Ophthalmol. 2005 Dec;40(6):701-10. View abstract
• Kim HR, Kim SD, Kim SH, et al. "Cytomegalovirus retinitis in a patient with dermatomyositis." Clin Rheumatol. 2006 Mar 15; [Epub ahead of print]. View abstract
• Natural Standard: The Authority on Integrative Medicine. www.naturalstandard.com. Copyright © 2009. Accessed March 10, 2009.
• StLukesEye.com. www.stlukeseye.com. Accessed March 10, 2009.