CMV Retinitis

CMV Retinitis – General Information

Cytomegalovirus is an omnipresent DNA virus which affects more than half of the adults worldwide. In the first stage, the infection is asymptotic; furthermore, the virus may remain latent for an undefined period, usually until the sufferer’s immunity is endangered. This virus can affects most of the organs of the human body: the lungs, the gastrointestinal tract, the skin, the brain, the peripheral nerves or the eye. CMV Retinitis is an infection caused by a cytomegalovirus and it is located in the eye. It is described as a necrotizing of the retina. This is a serious problem which, if left untreated, can lead to total blindness.  
Apart from being a dangerous infection, CMV Retinitis affects a large number of people; only in the USA, it affects about 70% of the adults. In addition, it appears as a common symptom of patients with AIDS. In what concerns the general rate of frequency, the studies show that this disorder is more common in the undeveloped areas, where the number of people with HIV virus is also bigger. CMV Retinitis usually leads to the loss of visual acuity; in addition, if the patient does not receive any treatment, he can experience complete blindness. The loss of visual acuity appears because the disease spreads in the posterior pole and damages the central vision. Furthermore, in most of the cases, this disorder permanently ruins the retina and, even with treatment, such damages are hard to repair.  The number of infections is the same in the case of men and women.

CMV Retinitis - Symptoms

There are some specific situations which can lead to the appearance of CMV Retinitis, such as some internal diseases or some drugs which were administrated in a wrong way. The most frequent causes are the following:

• Administration of  chemotherapy
• Lymphoma
• Leukemia
• Aplastic anemia
• Acquired HIV

This disease evolves quite quickly therefore the symptoms and signs are easy to notice. The most common ones are:

• Blurred vision: this is an ophthalmologic complaint, which usually leads to blindness. It is characterized by a distortion of vision and a reduction of the field of vision.  It can affect only one or both eyes. If it is diagnosed in an early stage, it can be successfully corrected and treated
• Blind spots
• Floaters
• Decreased acuity of the vision
• Loss of the peripheral vision

In most of the cases, the disease affects one eye and then expands to the other. If the sufferers does not benefit of any treatment at all, the retina will be completely ruined in less than 5 months and the patient will suffer of blindness. The bad part of this disease is the fact that the treatment is not effective in all the cases; moreover, even if the sufferer receives treatment, the disease can progress to total blindness. One of the possible reasons for this is the fact that the virus starts to be resistant to the administrated drugs. In other cases, CMV Retinitis can result in the complete detachment of the retina; in such situations, blindness appears immediately.

CMV Retinitis - Treatment

The most common procedures in the case of patients who suffer from CMV Retinitis are the following: Ganciclovir implant: this kind of implant liberates ganciclovir for a period of 3 to 7 months. However, this kind of treatment is effective just for an eye. Possible side effects can include: retinal detachment, endophthalmitis, vitreous hemorrhage, hypotony; Vitreoretinal surgery: in about 25 % of the sufferers of this disease, retinal detachment is possible. The problems which can lead to retinal detachment are the numerous holes in a number of places on the retina. These holes can be treated using vitrectomy, endolaser or air-fluid exchange; Fomivirsen implant: this form of therapy is administrated only if the patient does not respond to any other treatments; Intravitreal injections with foscarnet, cidofovir or ganciclovir: these kinds of injections provide intraocular drugs, but only for short periods of time. Injections are recommended when the administration of the drugs must be made quickly. The complications which can appear in the case of injections are: endophtalmitis or hemorrhage.

In order to obtain a sure diagnosis and to benefit from the best form of treatment, a patient should consult more doctors. Firstly, the sufferer should visit an infectious disease specialist who could provide medical care. The doctor must evaluate the general medical condition of the patient; he should also consult him in order to detect any other infections (gastroenteritis, pneumonitis). Another recommendation is to determine if the patient suffer from AIDS or not. In addition, the patient who suffers from CMV Retinitis should permanently visit an eye doctor; the visits should be established considering the gravity of the infection and the recovering process. In addition to these actions, the patient should be carefully monitored in order to prevent sudden reappearance of the disease or any other complications. If an implant is needed, the patient can delay the intervention for a certain period of time (no longer than 6 months), only if he continues the oral treatment.  

In most of the cases, the sufferers of CMV Retinitis need surgical intervention; this intervention does not necessary mean the necessity of an implant, but the repair of retinal detachment, an intravitreal implantation or the ganciclovir injections needed before the implant. In what concerns the oral treatment for CMV Retinitis, there are several antiviral drugs which can be prescribed. These drugs should however be tailored to every patient, considering the patient’s response and the evolution of the disease. These drugs must be taken permanently, unless the disorder improves drastically. In most of the cases, in order to obtain a sure diagnosis, the patients have to repeat the tests. The symptoms which usually require more than one test are: floaters, vision loss or a possible defect of the visual field. Patients should be permanently informed about the evolution of their disease and any possible treatment.  They should also be aware of the side effects of the drugs they are prescribed. In order to diminish the frequency of CMV Retinitis, people should be better informed about the transmission of HIV.