Trichiasis describes the situation where lashes rub against the cornea. This can involve both the upper and lower lids. This may occur where there is/are:
- Aberrant lashes, which point the wrong way
- Scarring conditions such as blepharitis, trachoma and others
- Entropion which can turn the lashes against the cornea
- Distichiasis, which usually runs in the family, where there is an extra row of lashes
- Metaplastic lashes, are isolated lashes arising from the wrong spot on the lid which often point the wrong way
You can see the extra row of lashes in this diagram. They may rub on the cornea and cause irritation, typically later in life.
This is a child with epiblepharon, where there is extra muscle and skin in the lower lid, which rolls the lashes onto the cornea, causing irritation. The situation can be remedied by removing a small strip of skin and muscle.
When the lashes abrade the cornea there is irritation, redness and watering. The cornea can become infected resulting in keratitis, which is a potentially sight-threatening condition.
- Epilation, lashes are individually plucked with epilation forceps (tweesers). The lash will usually come back but you may be lucky.
- Electrocautery, the lash follicle is cauterized with a diathermy needle after a local anaesthetic has been given. This is a useful treatment for a few lashes.
- Cryotherapy, is a freezing treatment, given after local anaesthetic, which stops the lashes from growing. It is suitable when there are many lashes involved.
- Surgery may be require to re-position the eyelid.
Banner image: A normal set of eyelashes.