Trichiasis is a condition in which the eyelashes grow toward the eye, although the eyelid and the position of the eyelash roots are normal. It causes corneal and conjunctival erosion, leading to foreign body sensation, discharge, and tearing.
It differs from entropion, in which the entire eyelid turns inward. However, entropion is often accompanied by trichiasis.
A condition in which eyelashes grow from near the meibomian gland openings, where eyelashes are normally absent, and the entire row of lashes turns inward is called distichiasis. It is included in the broad definition of trichiasis.
The exact prevalence of trichiasis is unknown. Globally, trachoma is the leading cause of infectious blindness, affecting approximately 10 million people. WHO estimates that about 3.2 million cases are awaiting surgery. Women are affected four times more often than men. In Japan, trachoma has decreased dramatically, so age-related changes and trichiasis associated with chronic blepharitis are the main conditions.
QWhat is the difference between trichiasis and entropion?
A
Trichiasis is an abnormality in the direction of eyelash growth itself, while the position of the eyelid margin is normal. In contrast, entropion is a condition where the entire eyelid turns inward, causing the eyelid skin, including the lashes, to contact the ocular surface. Both often occur together, but treatment strategies differ, so differentiation is important. Trichiasis is localized, with abnormally directed lashes mixed among normally oriented lashes. Entropion requires surgery to correct the overall eyelid position, whereas trichiasis primarily involves removal or redirection of the lashes themselves.
Abnormal eyelash direction: Inwardly directed lashes are found among normally oriented lashes. A habit of observing the entire eyelid under low magnification is effective in preventing oversight.
Corneal erosion/punctate superficial keratopathy: Fluorescein staining reveals punctate superficial keratopathy at the area of eyelash contact.
Corneal thinning/corneal opacity: In long-standing cases, corneal thinning and opacity occur. Pseudopterygium and corneal astigmatism may also be induced.
Trauma or inflammatory scarring can also cause trichiasis. In trachoma, conjunctival scarring from repeated infections is the main cause of trichiasis 1).
Long-term use of prostaglandin eye drops can cause eyelashes to grow longer, curl, and lead to symptoms of trichiasis.
Chemotherapeutic agents such as docetaxel (taxane) and trastuzumab have been reported to cause cicatricial entropion and trichiasis3). Histopathology shows chronic inflammation, dermal fibrosis, and squamous metaplasia 3).
QCan chemotherapy cause trichiasis?
A
Cases of cicatricial entropion and trichiasis have been reported with docetaxel (taxane anticancer drug) and trastuzumab (anti-HER2 monoclonal antibody) 3). After administration, chronic inflammation of the upper eyelid occurs, leading to squamous metaplasia of the meibomian glands and progression to trichiasis and cicatricial entropion3). Histopathology confirmed chronic inflammation, dermal fibrosis, and abnormal epithelial differentiation 3). Recurrence after multiple surgeries is common and refractory, so early management with collaboration between oncologists and ophthalmologists is recommended 3).
Slit-lamp microscopy: Use low magnification to survey the entire eyelid and identify abnormal eyelash direction. Using a diffuser makes findings easier to observe.
Fluorescein staining: Reveals punctate keratopathy and corneal erosion at the contact points of the lashes. It is important to perform this simultaneously with examination of the ocular surface.
History: Ask about the frequency of foreign body sensation. This helps determine the timing of follow-up visits according to the eyelash cycle (approximately 1 month). Also check whether the patient has pulled out lashes themselves.
Differential Diagnosis and Precautions
Differentiation from entropion: Trichiasis is localized and the eyelid position is normal. In some cases, entropion becomes apparent only after forced closure followed by opening, so observe in conjunction with corneal and conjunctival findings.
Blink test: Pull the lower eyelid downward to correct entropion, then ask the patient to blink. If entropion recurs with blinking, it is involutional entropion; if it recurs regardless of blinking, it is cicatricial entropion.
Exclusion of malignancy: Trichiasis may be the initial symptom of a malignant eyelid margin tumor. Caution is needed if accompanied by eyelash loss.
Epilation: The simplest management method. Eyelashes are removed with forceps under a slit-lamp microscope. Since they regrow after 1–2 months, regular removal is required. Surgery is needed for a permanent cure.
Artificial tears and eye ointment: Prescribed as adjunctive treatment for corneal epithelial disorders. If corneal erosion is present, hyaluronic acid eye drops are used.
Therapeutic contact lenses: May be used to protect the cornea.
Surgical Treatment
Electrolysis of eyelashes: The procedure itself is simple, but because the hair root is not coagulated under direct visualization, the recurrence rate is high. It is not suitable for a large number of misdirected lashes. Contraindicated in patients with cardiac pacemakers; photocoagulation or cryocoagulation should be considered.
Hair root excision: There are methods for removing one lash at a time or multiple lashes at once. The hair root directly above the tarsal plate is reliably removed.
Lash rotation surgery: Includes the Machek method (moving the abnormal lash area with Z-plasty) and the Spencer-Watson method.
Tarsal rotation surgery: For trachomatous trichiasis, BLTR (bilamellar tarsal rotation) or PLTR (posterior lamellar tarsal rotation) is recommended 1).
In trachomatous trichiasis, a single oral dose of azithromycin postoperatively reduces the risk of recurrence by 18% compared to 6 weeks of tetracycline eye ointment (OR 0.82, 95% CI 0.69–0.99) 1).
For localized cicatricial entropion and trichiasis, a buccal plug technique using a buccal mucosa graft has been reported 2). It avoids conjunctival incision and mechanically separates the anterior and posterior lamellae to eliminate corneal contact by lashes 2). No recurrence was observed in all 4 cases during a mean follow-up of 5.16 months 2).
QWhat is the recurrence rate of trichiasis after surgery?
A
In a systematic review and meta-analysis of trachomatous trichiasis, the pooled postoperative recurrence rate was 19% (range 18–21%) 1). Risk factors for recurrence included older age (OR 0.63 for younger age group indicating lower risk), preoperative severity (higher risk with major trichiasis), and postoperative use of tetracycline eye ointment (single-dose azithromycin had lower recurrence, OR 0.82) 1). Although WHO recommends a rate below 10%, many studies report recurrence rates exceeding this recommendation 1).
QWhat is the buccal plug technique?
A
The buccal plug technique is a minimally invasive surgical approach for localized cicatricial entropion and trichiasis2). After separating the anterior and posterior lamellae, a square portion of the anterior lamella containing the problematic eyelash follicles is excised, and a buccal mucosal graft harvested from the lower lip is inserted as a “plug” to mechanically separate the anterior and posterior lamellae 2). Advantages include avoiding conjunctival incision and minimal impact on the aesthetic contour of the eyelid 2). However, it is not indicated for extensive cicatricial lesions and is positioned as an adjunctive option for localized lesions 2).
The pathology of trichiasis involves anterior migration of the mucocutaneous junction due to blepharitis or blepharoconjunctivitis, with slight marginal entropion at the posterior lid margin affecting the rigid fibrous tissue at the hair root, altering the direction of eyelash growth.
When eyelashes contact the cornea, repeated micro-damage to the corneal epithelium occurs. Chronic irritation can progress to corneal epithelial keratinization, thinning, and perforation. Ultimately, corneal opacity leads to vision loss.
In trichiasis caused by chemotherapeutic agents (docetaxel, trastuzumab), the drugs induce chronic inflammation and interstitial fibrosis in eyelid tissues 3). Decreased conjunctival goblet cells lead to severe dry eye, and mucosal squamous metaplasia progresses 3). Abnormal differentiation from non-keratinized stratified epithelium to non-secretory keratinized epithelium triggers meibomian gland degeneration, trichiasis, and cicatricial entropion3).
Trachomatous trichiasis results from conjunctival scarring due to repeated C. trachomatis infections. Contraction of scar tissue causes the eyelid margin and eyelashes to turn inward, contacting the cornea1). Postoperative recurrence involves persistent active conjunctival inflammation, age-related degenerative changes in eyelid tissues, and preoperative severity of trichiasis 1).
A meta-analysis integrating 18 studies revealed that the pooled postoperative recurrence rate of trachomatous trichiasis is 19% 1). Postoperative administration of a single dose of azithromycin significantly reduced the recurrence rate 1). Regular surgical training, close postoperative follow-up, and patient education are considered essential for preventing recurrence 1).
The buccal plug technique has been reported as a minimally invasive approach that avoids conjunctival incision 2). Compared with conventional tarsal rotation surgery, it has less aesthetic impact and may be a useful option for localized cicatricial entropion and trichiasis2).
Multiple cases of cicatricial entropion and trichiasis caused by docetaxel and trastuzumab have been reported 3). Since recurrence occurs after surgery as long as the chronic inflammatory process persists, an approach prioritizing conservative management and awaiting resolution of the inflammatory process has been proposed 3). Early intervention through collaboration between oncologists and ophthalmologists is important 3).
Adimassu NF, Assem AS, Fekadu SA. Postoperative trachomatous trichiasis: a systematic review and meta-analysis study. Int Health. 2023;15:623-629.
Saffari PS, Roelofs KA, Rootman DB. The buccal plug: A technique for management of focal cicatricial entropion and trichiasis. Indian J Ophthalmol. 2025;73:305-306.
Galindo-Ferreiro A, de Prado Otero DS, Marquez PIG, Schellini S. Recurrent and recalcitrant upper lid cicatricial entropion following combined chemotherapy: Clinical and pathology correlation. Saudi J Ophthalmol. 2021;35:347-349.
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