Trachoma - an Easily Preventable Blinding Disease

Trachoma is a severe infectious follicular conjunctivitis frequently seen in developing countries. It is known to affect children in the age groups of 5 to 10 years, with complications starting by 20 to 30 years. In severe cases, it is known to cause a variety of eyelid malformations by its tendency to produce scarring. It is a major public health problem and deserves attention from both the common man in terms of preventive measures to be taken and hygienic practices to be followed and also city planners and executives as sanitation and hygiene are the major factors responsible for this disease.

Trachoma is caused by Chlamydia trachomatis, a bacteria that is gram negative with a life cycle tailormade to evade our natural immune defense mechanisms. The infective form of this organism called an elementary body is an inert, tough protective shell harboring the infectious organism. Through this form, chlamydiae are capable of surviving extreme conditions that would generally instantly kill the organism. The elementary body after gaining entry into our body infects our bodily cells by a process called endocytosis, wherein it coats itself with the cells' own coating and starts multiplying inside.

During this whole process, the organisms are protected from our immune protective mechanisms through a variety of countermeasures by the organism. Once inside the cell, the elementary body becomes active and transforms into a reticular body and starts multiplying within the host cell until the host cell can no longer sustain the rate of multiplication of these infectious bodies. The reticular bodies once again transform into elementary bodies before rupturing the host cell and moving on to infect another cell and continue the same cycle all over again.

The Main Mode of Spread

The main modality of the spread of the disease is by direct contact, that is, an infected person sheds the infectious organism in his eye discharge and harbors the organism in his bodily secretions. Any contact with an infected person can precipitate the infection.

Symptoms and Signs

1. In milder forms -

a. Follicles - these are the proliferation of lymphoid cells as an immune reaction to the spread of the chlamydia. This is the earliest and most characteristic sign. At this stage, the disease can be easily reversed and will not cause any permanent damage to the patient’s eye.

b. Severe inflammation - the eye becomes red and starts to water. This is also a feature seen in early disease and should raise an alarm that the condition needs to be urgently treated.

2. In severe forms -

a. Scarring - in this stage, the inflamed and reactive tissues have been replaced by scar or dead tissues. This indicates a stage of irreversibility and the tissue once scarred does not regain its normal elasticity and function. The scarred tissue is relatively rigid and non-malleable and gives rise to complications of the lid such as inward turning of eyelid margins.

b. Trichiasis - in more severe forms of scarring, the inward-turned eyelashes will rub against the cornea, grating it to cause erosions and ulcers. These ulcers and erosions, if not treated properly, will lead to the formation of permanent corneal opacification, thus blinding the patient for life. The only cure for such a blindness is by surgery and the outcomes of the surgery are not 100 % good, that is, not all patients improve with surgery.

Treatment Options Available

Medical measures used for treatment include both drugs and surgeries.

The best drug for trachoma in early stages is Azithromycin, but Gentamycin can also be used. Surgery is reserved for complications such as trichiasis which needs bilamellar tarsal rotation and corneal opacification

Preventive Measures

The disease of trachoma is an easily preventable one and can be avoided by the following measures.

Stop eye rubbing - this is a relatively simple way to avoid infections from getting into the eye. The main mode of spread is from the bodily secretions as previously mentioned. Hence, the organism's mode of entry into the eye is by contact of the eye with the hands. Once eye rubbing is avoided the organism has no way to gain access to the ocular surface and hence very effectively prevents the infection.

Maintaining hygienic practices - regular handwashing has been shown to drastically reduce the transmission of not only trachoma but also many other ocular viral and bacterial infections. Hand washing often and especially before greeting others is the main mode of trachoma spread.

Facial hygiene - this prevents the transmission of infection by flies and airborne insects which harbor the infection and transmit it by contact. So, maintain facial hygiene with regular bathing and face washing with soap and water.

Public health measures include using toilets for defecation than in open air, promoting hygiene of the surrounding by preventing stagnation of sewage water and garbage dumps.

This disease is seen in most parts of the world, it is common among the poor and uncared. A few measures of personal hygiene and respect for our environment can go a long way in preventing this transmissible cause of blindness.

For more information consult an eye care ophthalmologist online

SamKyley General Practitioner