By Dr. Veena G.D., MBBS, DOMS  

Trichiasis, a very common lid abnormality, is defined as the misdirection of eyelashes towards the eye ball. The misdirected lashes may be spread across the entire lid or in a small segmental distribution. Mechanism of Action The causes of trichiasis are involutional changes of lid.  Trichiasis can occur in all ages; though most commonly is seen in adults. Epiblepharon, one of the common causes of trichiasis, is found primarily in children. Epiblepharon is a congenital disorder that occurs when the pretarsal orbicularis (upper lid plate) and the skin override the lid margin, causing the lashes to assume a vertical or in-growing position. The lashes occasionally rub the cornea. It can also be caused by Trauma, Postsurgical scarring of the lid.

Prolonged period of eyelashes ingrowing continuously irritatesthe cornea and the lower conjunctiva.

Clinical Presentation

Upper lid entropion and trichiasis commonly are seen with trachoma (swimming pool conjunctivitis resulting in scarring of the lids). Trichiasis is a leading cause of decreased vision with this trachoma and is associated with upper lid entropion. Rule out whether the patient had a history of herpes zoster ophthalmicus (HZO). Zoster can cause scarring of the eyelid. Trauma, whether or not it is surgical, is a common cause of misdirected lashes.

Physical Examination

Examine both the upper and the lower lids to look for lash misdirection. This examination may require use of a slit lamp to find the offending lashes if the trichiasis is limited and focal. Look for signs of posterior lamellar scarring. This requires flipping the upper lid, which may be very difficult in cases of trachoma. Look for symblepharon (sticking of the eyelids to the conjunctiva) formation and fornix scars. Look for signs of involution entropion and horizontal lid laxity. Try the snap back test.

Treatment

The conservative treatment is epilation (manual removal of misdirected eyelash one by one on slit lamp). If the condition is chronic then it has to be surgically treated. Lubricants, such as artificial tears and ointments, may decrease the irritant effect of lash rubbing. Radiofrequency ablation of lashes and follicles is extremely effective. Wedge resection of the lid segment requires a full-thickness resection of the lid margin; in many cases, it may be excessive. Lash and follicle repositioning surgery should be directed toward the anatomical cause of the problem. Prognosis is generally good. Frequent follow-up care and immediate attention to complications, recurrence, or corneal complications improve the long-term prognosis.

Patient Awareness

Watch for signs of new lash growth, and return for re-treatment.