Trichiasis is an eye disorder where eyelashes grow inward, causing them to rub against the surface of the eye. This misdirection causes chronic irritation, often feeling like a foreign object beneath the eyelid. The constant friction can lead to serious complications if the condition is not addressed. Specific treatment is required to protect vision and restore comfort.
Defining the Condition
Trichiasis is the term for eyelashes that are incorrectly oriented, growing toward the eyeball instead of curving outward. These misdirected lashes scrape against the ocular surface, specifically the cornea and the conjunctiva. The constant mechanical abrasion causes discomfort and can progressively damage the eye’s surface.
It is important to distinguish this from entropion, where the entire eyelid margin rolls inward toward the eye. In trichiasis, the eyelid position remains correct, but the hair follicle is improperly directed, causing only the lash to turn inward. This distinction matters because treatment approaches focus either on the lash follicle or the eyelid structure. The condition most often affects the lower eyelids, though it can occur on the upper lid as well.
Identifying the Underlying Causes
The shift in eyelash growth direction typically results from scarring or chronic inflammation that physically distorts the hair follicles. Causes can be broadly grouped into inflammatory, infectious, traumatic, and age-related categories.
Long-term inflammation from chronic blepharitis, characterized by eyelid swelling and oily debris, is a frequent trigger. Infectious diseases are a significant cause, particularly trachoma, a severe bacterial infection. Repeated trachoma infections lead to severe scarring on the inner eyelid, which contracts and pulls the eyelashes inward. Other infections, like ocular herpes zoster, can also cause scarring that disrupts normal lash growth patterns.
Trauma to the eyelid, such as from burns or chemical injuries, can cause cicatricial changes that force the eyelashes to grow incorrectly as the tissue heals. Sometimes, trichiasis occurs without a clear underlying cause and is termed idiopathic, though it is more common in adults due to cumulative inflammation and aging.
Recognizing Symptoms and Signs
The most frequent complaint associated with trichiasis is the sensation of a foreign body in the eye. This constant irritation leads to several symptoms, including chronic eye redness (conjunctival injection) and excessive tearing (epiphora). Patients often develop photophobia, which is increased sensitivity and discomfort when exposed to bright light.
The physical rubbing of the lash against the cornea is the source of potential long-term damage. This friction can cause superficial corneal abrasions, or small scratches on the eye’s surface. If left untreated, these abrasions can progress to corneal ulcers, which involve deeper tissue loss and carry a high risk of infection. Chronic damage can result in corneal scarring and clouding, impacting visual clarity.
Management and Treatment Options
Treatment for trichiasis aims to eliminate the source of irritation to prevent permanent corneal damage and restore comfort. Temporary relief can be achieved using lubricating eye drops and ointments, which provide a protective barrier. Manual epilation, or plucking the lashes with forceps, is a quick office procedure, but the eyelashes typically regrow within four to six weeks, often returning misdirected.
For a more lasting solution, definitive treatments focus on permanently destroying the hair follicle.
Electrolysis and Laser Ablation
Electrolysis uses a fine probe to deliver an electric current and heat directly to the follicle. Success rates vary, with recurrence rates reported over 40% due to difficulty ensuring complete follicle destruction. Laser ablation utilizes a focused beam of light to destroy the follicle, with success rates ranging from approximately 39% to 88%.
Cryotherapy and Surgery
Alternatively, cryotherapy involves freezing the lash follicle to cause cell death. While effective, cryotherapy has been associated with a higher risk of complications, such as eyelid scarring and pigment changes. Surgical correction is reserved for cases where a large segment of the eyelid margin is affected due to significant scarring, involving procedures to reposition the anterior lamella of the eyelid.