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A visually impaired man carrying his farm tools.
Eliyabu, Uganda. He has trachomatous trichiasis and needs eyelid surgery on both eyes before he loses his sight completely.

An introduction to trichiasis

Trachomatous trichiasis is an advanced stage of trachoma. It is defined as having one or more eyelashes touching the surface of the eye. In 2016, an estimated 3.2 million people with trichiasis need surgery to avoid blindness.

The World Health Organization (WHO) recommends surgery to reduce the risk of sight loss from trachomatous trichiasis. However, over the last decade only 50% of the global surgical target for trichiasis surgery has been achieved. This means we will not reach everyone who needs surgery until 2032, unless we increase the surgical rate across affected endemic communities.

Why do people get trichiasis?

Repeated infection by Chlamydia trachomatis causes severe inflammation of the conjunctiva. This, along with the response by the immune system to the infection, leads to irreversible changes within the fibrous connective tissue of the eyelid and scars form on the tarsal plate and conjunctiva of the eye.

This scar tissue leads to changes in the eyelids and turning the eyelid margin inwards (entropion) and this may be severe enough to turn the eyelashes inwards.

The eyelashes come into contact with the surface of the eye scratching the cornea during blinking, which is both painful and sight threatening. This is trachomatous trichiasis (TT).

This step in the progression of trachoma disease can be succinctly captured as “scars today, trichiasis tomorrow.”

Eventually, the rubbing of the eyelids damages the cornea leading to opacification (known as CO) and blindness which you can see in this eye with trichiasis.

Eye with a corneal opacity Trichiasis © Matthew Burton/LSHTM CC BY-NC-SA

Who is affected by trichiasis?

The rate of progression from scarring of the conjunctiva to trichiasis varies across different communities. Progression depends how endemic trachoma is in a community - ongoing episodes of inflammation of the conjunctiva is a major risk factor.

Trachomatous trichiasis mostly affects older people. However, in some highly endemic trachoma regions it is not unusual to find young children with trichiasis. Across most settings, women are four times more likely than men to get trichiasis, regardless of age.

How do we prevent blindness from trichiasis?

Once someone has trichiasis, they are up to eight times more likely to develop corneal opacity. We can improve access to, awareness and acceptance of, surgery for trichiasis by selecting an appropriate procedure and using a trained team to deliver the surgical service at a community level.

The earlier surgery is provided, the better the outcome for preventing blindness and visual impairment from trichiasis.

People with trichiasis do not always come forward for treatment. There are many reasons, depending on setting and personal circumstances.

Each trachoma control programme needs to put a system in place that tries to understand why people don’t come for trichiasis surgery in their setting. This will help to actively find, counsel and provide the best treatment (either surgery or sometime epilation) to people with trichiasis.


Nyakeira (young girl in South Sudan)

A few years ago my eyes started hurting me - they were tearing and sensitive to smoke and light. My eyelashes started touching my eyes in the sunlight, so I sit in the shade with the elderly while my friends go out to play. The most I could do was pound and grind cereals for my mother, because I was nearly blind. None of my friends or family knew what to do about my eye pain. My mother prayed that I could get medical attention and I could only cry thinking about my hopeless future.


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Eliminating Trachoma

London School of Hygiene & Tropical Medicine

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