Mycobacterium tuberculosis, the etiologic agent of Tuberculosis (TB) is capable of causing infection in many organs including eye; ocular tuberculosis can involve any part of the eye and can occur with or without indication of complete focus of TB It is one of the major diseases causing mortality and morbidity in developing countries. Treatment encompass antitubercular agent, Ethambutol, which inhibits the transfer of mycolic acids into the cell wall of the tubercle bacillus. It may also inhibit the synthesis of spermidine in mycobacteria. Its bactericidal action enables the drug to penetrate human cell membranes to exert its lethal effects on many tissues and organs including eyes. The present article discusses the critical evaluation of infection control issues for patients with tuberculosis in the eye clinic department.Tuberculosis or TB is a contagious, airborne disease of the lungs that is potentially spread to other parts of the body and may be fatal. The disease can now be treated, cured, and prevented. However, in spite of the constant efforts scientists are not able to eradicate it completely. It spreads to the most sensitive population or those at higher risk especially the elderly people with reduced immunity or people with immunocompromised condition or suffering with AIDS.Elderly people are especially vulnerable for a number of reasons. First, the disease can take years to become active, so an older person may have gotten the disease earlier in life and only discovered it after it became active. Second, people who live in nursing homes and similar facilities are often in close contact with each other and the disease can spread more easily in such conditions. Third, the body's immune system becomes weaker as a person grows older and older people may find it more difficult to hold off an attack of the tubercle bacillus. Migration of individuals from developing countries has further enhanced the chances for the spread of disease. People who abuse alcohol and illegal drugs are also at high risk for the disease.
Transmission is through droplets. When a person suffering with TB coughs or sneezes, he or she releases a fine mist of water droplets containing thousands of the bacteria. A person(s) nearby the patient may inhale those water droplets and also the bacteria. These bacteria can then travel to that person's respiratory system and cause a new infection. Tuberculosis is not transmitted by contact with a person's clothing, bed linens, or dishes and cooking utensils. A fetus may become infected, however, by taking in bacilli from the mother ((Biswas, 1995, Sheu, 2001, Kotake, 1994, Rosen, 1990).
Inhaled bacilli, however, may survive the immune system. They may travel throughout the body to organs other than the lungs. In some cases, the bacilli remain active enough to cause tuberculosis. In about 5 percent of all cases, a person develops tuberculosis within twelve to twenty-four months of being exposed to TB bacteria, followed by the treatment regimen.
The most popular anti-tuberculosis medications is ethambutol. It has emerged as the most common cause of toxic optic neuropathy, followed by isoniazid. For initial tuberculosis therapy, the dose starts with 15 mg/kg per day, this is recommended to minimize toxicity. If a patient has had earlier tuberculosis therapy, then the dose starts with 25 mg/kg/day for 60 days followed by 15 mg/kg/day. It is evident that, Ethambutol toxicity is dose and duration dependent. With doses of more than 35 mg/kg/day, up to 18% of patients develop optic neuropathy. The prevalence diminishes to 5% to 6% with doses of 25 mg/kg/day and further decreases to less than 1% for doses of 15 mg/kg/day. Optic neuropathy has been reported with doses as low as 12 mg/kg/day. Ethambutol toxicity widens, on normal, 3 to 5 months after the initiation of therapy, but initial presentation can range from 1.5 to 12 months. The ocular conditions associated with the ethambutol encompass bilateral decreased vision with dyschromatopsia, loss of color vision may be