Antiretroviral Therapy

Antiretroviral or ARV is used to treat HIV virus. A combination of ARV used to treat HIV - Antiretroviral therapy. Patients tend to take 3 or more combinations of ARV medication called the combination therapy. Currently the main treatment for HIV is through Antiretroviral therapy.

Antiretrovirals aim to inhibit the process which the virus resorts to kill T lymphocytes. More than 20 antiretroviral drugs have been approved to treat HIV. Some Antiretroviral drugs have been combined into one single pill known as a fixed dose combination. Different dosage of medicine is prescribed for different people depending on the severity of the infection in the blood.

ART medication cannot cure or treat HIV; however it helps in preventing the growth of the virus and reduces the risk of transmitting it to others. This prevents the virus from multiplying and slows down the virus and thereby HIV. Having less HIV in the body gives the immune system of the body a chance to recover and fight infections.

Significant advances have been made in this therapy since its introduction in 1987. ART involves ingesting a combination of HIV medicines on a daily basis as prescribed by the physician. If left untreated HIV can develop into AIDS. If only one drug is taken, HIV will become resistant to the drug very soon and the drug will stop working. Hence a combination of drugs is used. ART is often a lifelong treatment that is currently helping numerous HIV affected people lead a better quality of life. The effectiveness of the treatment largely depends on the adherence of medicine intake schedule.

When to start ART depends on the patients' need and condition. A blood test called the CD4 count is taken to measure the number of CD4 cells in a sample of blood. CD4 cells are infection-fighting cells in the immune system of the human body. HIV attacks and destroys these CD4 cells, thus making it difficult for the body to fight infection. A low or dropping CD4 count indicates that HIV is advancing and damaging the immune system. Under the guidance of a physician when the patient begins ART, the CD4 count begins to improve which indicates that the immune system in the body is recovering.

Physicians also may order a blood test to check and measure HIV by checking the viral load in the blood i.e. the amount of the virus in the bloodstream. ART aims at reducing the viral load in the blood to an extent that it can't be traced any longer while testing. HIV virus though present in the blood will be very low - not sufficient to cause any symptoms.

Combination ARV therapy is also available and is known as highly active ART or HAART. With the availability of HAART, HIV-1 infection is manageable as a chronic disease in patients. Antiretroviral drugs are used in combinations of three or more classes of drugs, called Combination Therapy. This therapy helps prevent drug resistance in patients. Six classes of drugs, Antiretroviral agents, exist currently:

• Chemokine receptor antagonists (CCR5 antagonists) such as maraviroc.
  
• Fusion inhibitors (FIs) such as enfuvirtide.
  
• Integrase inhibitors (INSTIs) such as dolutegravir and raltegravir.
  
• Nucleoside reverse transcriptase inhibitors (NRTIs) such as abacavir, emtricitabine and tenofovir.
  
• Non-nucleoside reverse transcriptase inhibitors (NNRTIs) such as efavirenz, etravirine, and nevirapine.
  
• Protease inhibitors (PIs) such as atazanavir, darunavir, andritonavir.

Each class targets a different step in the life cycle of the virus. Each of these drug classes includes more than 25 HIV medicines that are approved to treat HIV infection. ART regimen includes three or more Antiretroviral from at least two different classes.

Drugs have to be taken at the right time and in the right way for the drugs to work well. The regimen requires plenty of discipline. The drugs may cause side effects in a few. If patients stop taking the drug, they may develop resistance to the drug and thereby will stop responding to the treatment when continued at a later stage.

Few of the commonly reported side effects include loss of appetite, fatigue, depression, mood changes, weight gain, sleep disturbance and metabolic disturbance. ART is available for pregnant women so that they don't pass on the virus to the fetus in the womb. Post delivery, the mother is advised not to breast feed the baby as she may pass the HIV virus through this to the baby. Though ART is not a complete cure for HIV, it serves the purpose to:

• Reduced HIV viral load in the blood.
  
• Enhanced quality living for patients inflicted with HIV.
  
• Lesser damage to the immune system.
  
• Reduced transmission of HIV in the society.

Though ART is considered to be a great regimen in handling HIV, it has few limitations such as:

• Strict adherence to medication regimen; few tablets need to be taken at the same time of the day, everyday.
  
• Expensive medicines have to be continued life long.
  
• Side effects
  
• Virus cannot be eradicated completely from the body.
  
• Relapse is possible on discontinuation of drugs.
  

CD4 Count Test

The CD4 Count Test is an indicator of the working of the immune system. By measuring the number of CD4 T lymphocytes or CD4 cells in the blood, it helps to predict and assess the progression of HIV. This count helps in planning antiretroviral therapy or ART. Monitoring the CD4 count through regular blood tests helps to determine the efficacy of the ART and whether the patient is at risk for other infections.

The CD4 lymphocytes are WBC that play a vital role in infection protection. HIV virus tag on to CD4 cells to propagate and spread the infection within the body. Thus an infected person will notice a reduced count of CD4 cells (less than 200 cells/mm3) when the normal range of CD4 cells is from 500 cells/mm3 to 1,200 cells/mm3.

Successful ART results in reduced CD4 count and lesser viral load in the blood. CD8 cells are another type of WBC that work against infections in the body including HIV.

Cataract Surgery

Cataract surgery has made extraordinary and exciting advances over the past 20 years. Last year, approximately 2.7 million Americans underwent cataract surgery. Greater than 95% of those patients now enjoy improved vision. State-of-the-art cataract surgery is now a safe, effective, and comfortable procedure performed almost exclusively on an outpatient basis.

Most cataract surgeries are now performed using microscopic size incisions, advanced ultrasonic equipment to fragment cataracts into tiny fragments, and foldable intraocular lenses (IOLs) to maintain small incision size. Cataract surgery today is the result of extraordinary technological and surgical advancements that allows millions of people to once again enjoy crisp and clear vision. A true marvel of modern medicine, cataract surgery may restore vision to levels you may have never thought possible.

When a cataract is removed, it is replaced with an artificial intraocular lens (IOL). There are a variety of IOLs that can be used in cataract surgery, and they each have their own set of advantages and disadvantages. No single IOL works best for everyone, and only your ophthalmologist can determine the most appropriate IOL for your needs. The FDA approval process for IOLs is among the most rigorous in the world. You can rest assured than any IOLs used in the U.S. have undergone very extensive testing for safety and efficacy. These same IOLs are also used for a refractive surgery procedure known as refractive lens exchange. In refractive lens exchange, the IOL is used solely in an attempt to reduce or eliminate the need for glasses or contact lenses. This article outlines some of the choices of IOLs that are available for use in cataract surgery and refractive lens exchange.

Fixed Focus Monofocal IOLs are used in the majority of cataract procedures. These lenses have the advantage of excellent quality distance vision under a variety of lighting conditions. Since these lenses have a fixed focal point which is generally set for distance vision, reading glasses are typically required for good near vision. For patients willing to use reading glasses for near tasks, these IOLs are an excellent choice. Several million lenses of this variety have been used for decades with an excellent safety record. Recent refinements in the optical quality of these lenses have allowed an even higher quality of vision than previously achievable.

Accommodating Monofocal IOLs are used in situations where both good distance and good near vision are desired without the use of spectacles. These IOLs have a single focal point, however, the focal point can shift position in space so that objects at distance are clear when the eye focuses on them, but when the eye looks at a near object the IOL will shift its focal point to bring the near object into focus. Accommodating Monofocal IOLs achieve this by physically moving inside the eye in response to the focusing action of the muscles of the eye. The only FDA approved IOL of this type is called the Crystalens™. Patients implanted with the Crystalens IOL generally enjoy near vision without glasses that is much better than those implanted with Fixed Focus Monofocal IOLs(2). In fact, results of the FDA trial for the Crystalens demonstrated that 98% of patients could see well enough to pass the driver's test and read a newspaper without glasses. Vision at the intermediate (computer screen) distance is superb with the Crystalens, making this an excellent IOL for those who spend a great deal of time on a computer.Cataract surgery today is typically performed using a microincisional procedure. To the patient, this means minimal discomfort during or after surgery, a more speedy recovery of vision, and reduced risk of induced astigmatism. This means less dependence on glasses afterwards.

Below, we've detailed the major steps of cataract surgery using a microincision procedure, phacoemulsification (ultrasonic cataract removal), and a foldable lens implant. This type of procedure is considered state-of-the-art for cataract surgery today. The procedure demonstrates basic principles only, however, and eye surgeons use many variations of the general theme, even from one case to another, depending on the type of cataract being removed. After discharge from the surgery center, patients will usually be asked to return for a follow-up visit later that day or the next day, however, this will be based on individual circumstances. Also depending on the type of incision and surgeon preference, some patients will be asked to wear a shield over the eye, particularly while sleeping. The eye should not be rubbed, or pressure placed directly on the eye through the eyelid, during the first few weeks following surgery. Eye drop medications will be required, usually consisting of antibiotic and anti-inflammatory medicines. These will often be tapered off during the first month after surgery.

The best vision may not be obtained until several weeks following surgery, but individual results vary considerably, depending on many variables. The great majority of patients may resume normal activities on the day of or day after surgery. Activities such as reading, watching television, and light work will not hurt the operated eye. Most surgeons arbitrarily recommend waiting 4 to 6 weeks before new glasses are obtained. This allows the eye to achieve considerable stability from a refractive standpoint and, therefore, the glasses prescription should be accurate and relatively stable.

Many patients are surprised at how clear their vision is after cataract surgery. Some patients may have better vision than they ever did before cataract surgery. Furthermore, depending on the degree of refractive error (need for glasses) prior to surgery, many patients will be much less dependent on glasses for far vision than they were before surgery. Patients will often notice that colors are brighter and more brilliant. The results are often dramatic.