Trachoma is an eye infection that affects both eyes. The World Health Organization's (WHO) statistics indicate that the disease is responsible for irreversible blindness in 1.2 million people worldwide. In total, trachoma has caused visual impairment in 2.2 million individuals. WHO also estimates that 41 million people have active trachoma infection.
Trachoma is particularly prevalent in children between the age of three and six. However, it may take years to manifest itself. It is also the most common cause of preventable blindness globally.
Also Known As
- Conjunctivitis - Granular
- Granular conjunctivitis
- Conjunctivitis - Chlamydia
- Egyptian ophthalmia
Causes and Risk Factors
Chlamydia trachomatis, a bacterium, causes trachoma. It starts as conjunctivitis which is also called pink eye. Failure to treat conjunctivitis can lead to scarring inside the eyelids. A condition called trichiasis then sets in where the eyelashes turn inwards in the direction of the eye. The eyelashes now scratch against the cornea, the transparent outer covering of the front part of the eye.
The irritated cornea can turn cloudy leading to corneal ulcers and ultimately, loss of vision. One single incidence of trachoma may not cause vision loss. It is the repeated infections that continually cause the scarring that may lead to blindness. Certain flies can also cause the spread of trachoma.
Risk factors include:
- Living in the rural areas of developing countries
- Direct contact with an infected nose, throat fluid or eye.
- Inadequate supply of water - There is less water to clean the face
- Poor facial hygiene - It will attract dirty flies which carry the bacteria
- Overcrowded living conditions - Mostly due to poverty which may see families sharing things like beds
- Limited toilet facilities leading to environmental contamination - This provides fertile ground for the breeding of flies
Signs & Symptoms
The symptoms of trachoma begin 5-12 days after exposure to the bacteria. They may include:
- Blurry vision
- Eye redness
- Corneal ulcer
- Pain in the eye
- Cloudy cornea
- Swollen eyelids
- Sensitivity to light
- Discharge from the eye
- Irritation of the eyes and eyelids or itchiness
- Swelling of lymph nodes just in front of the ears
- Eyelashes that have turned inwards, scratching the cornea (trichiasis)
The eye care professional will conduct an eye examination by doing the following:
- Check for intraocular pressure
- Take a medical history of the individual
- Check if the pupils are responding to light
- Ocular motility test to check for misalignment of the eyes
- Use a slit-lamp examination to light up the front part of the eye
- Peripheral vision test to see how well one can see from the sides
- Dilate the eye using eye drops to examine the retina and optic nerve
- A visual acuity test to determine how well someone can see from a distance
- Send to the laboratory a sample of the individual’s culture especially if the individual has recently visited an area where trachoma is common
Treatment for trachoma aims to clear the infection causing it and improve visual outcomes.
An eye doctor will prescribe antibiotics in the early stages of the disease. The main antibiotic for treating trachoma is azithromycin (taken orally). Another antibiotic is tetracycline ointment.
In 1998, a strategy called SAFE was implemented which has significantly reduced cases of trachoma. SAFE stands for Surgery, Antibiotic treatment, Facial cleanliness and Environmental improvement. SAFE was an offshoot of the Global Elimination of Blinding Trachoma (GET 2020) whose goal is to reduce instances of trachoma.
In case of advanced trachoma, eyelid rotation surgery is necessary to place the eyelids back into position. Surgery will also help to stop corneal scarring and improve eyesight.
If the cornea is severely damaged by scarring or clouding such that vision is impaired, a corneal transplant may be required. A healthy cornea from a donor replaces the damaged cornea.
Epilation is a surgical procedure that aims to remove eyelashes. However, the eyelashes may require frequent removal.
Trachoma that is treated with antibiotics in its early stages has no complications. If left untreated, trachoma may lead to blindness.
Antibiotics are effective in treating trachoma. However, due to poor hygiene, re-infection is common.
The prognosis for corneal transplant to replace a cloudy cornea does not always look good for trachoma patients.
Trachoma prevention requires the practice of good hygiene which includes:
- Accessing clean water
- Maintaining clean clothes
- Thoroughly washing the hands and face
- Eliminating breeding grounds for flies or reducing fly populations
- Not sharing items with anyone such as towels, wash clothes, bedding and eye makeup
- Giving antibiotics to an entire community if 10% of the population has trachoma. This action prevents the further spread of the disease.