Ingrown eyelashes are an abnormal condition in which the eyelashes grow backward so that they touch the eyeball. It is a common external eye disease in children, adolescents and the elderly, and is mainly caused by abnormal growth of the eyelashes. Eyelashes that grow in an abnormal direction, especially those that grow backwards toward the corneal surface, often rub against the corneal epithelium, causing symptoms such as foreign body sensation, photophobia, and tearing.
Normal eyelashes grow on the anterior lip of the eyelid margin and develop from the surface ectodermal epithelium, arranged in two to three rows of short, curved, thick hairs. The eyelashes are used to shield the eye from light and dust, to prevent foreign objects from entering the eye, and for cosmetic purposes. The eyelashes of the upper eyelid are more numerous, with 100 to 150 lashes and an average length of 8 to 12 mm, and the angle of the upper eyelashes is 110b to 130b when the eyes are open and 140b to 160b when the eyes are closed; the eyelashes of the lower eyelid have 50 to 80 lashes, with an average length of 6 to 8 mm and 100 to 120b when the eyes are open. There are metamorphic sweat and sebaceous glands with ducts that open into the eyelash capsule. The posterior lip of the eyelid margin has numerous small pores arranged in rows that serve as openings for the ducts of the lid glands, which themselves are located within the lid. Abnormalities in the angle of inclination of the eyelashes can be caused by changes in the angle of growth of the eyelashes or by diseases of the eyelid.
Causes
There are many causes of ingrown eyelashes, mainly in children and adolescents due to abnormal eyelash growth direction, lower lid redundancy, sometimes lower lid redundancy combined with medial canthus, and congenital entropion of the eyelid. In middle-aged and older adults, this is mainly due to inflammation of the eyelid conjunctiva and scarring of the lid margin, as well as various causes of entropion. There are two main types of causes of impingement, including impingement without eyelid entropion and impingement with eyelid entropion. Eyelid entropion can definitely cause impingement, but impingement is not always accompanied by eyelid entropion; it can be present alone. Entropion is the abnormal inward rolling of the lid margin toward the eye.
Disease Classification
1. Ingrown eyelashes without eyelid entropion: the eyelashes sweep toward the cornea simply due to the abnormal growth direction of the eyelashes or the skin pressure of the lower eyelid flap.
2. Ingrown eyelashes with eyelid entropion
(1) Congenital lid entropion
It occurs in infants and young children, only in the lower eyelid, with a higher incidence in Asians, and tends to occur in the proximal internal position of the lower eyelid. Pathogenesis: Most are caused by pulling of the medial canthus, overdevelopment of the orbicularis oculi muscle of the eyelid or underdevelopment of the lid. In some infants, the lower eyelid may be turned inward because of the fatty nasal root and the flatness of the nasal root, as well as the presence of the medial canthus and lower lid redundancy. Congenital entropion should be distinguished from lower lid redundancy, in which the lid margin itself curls inward, whereas the latter is a rare congenital abnormality in which there is a redundant skin crease on the medial side of the lower lid that pulls the eyelashes inward and contacts the cornea and conjunctiva, but the lid margin itself does not turn inward.
(2) Degenerative lid entropion
Degenerative entropion, also known as chronic spastic entropion or senile entropion, occurs mostly in the lower lid. muscle fibers curl upward and the orbicularis oris muscle in front of the orbital septum overlaps, resulting in inversion of the eyelid and also triggering an impingement.
(3) Scarring lid entropion
Scarring entropion is caused by contraction and pulling of the lid conjunctiva and lid scar, causing the eyelid to turn back toward the eyeball and can involve both upper and lower lids. It can be caused by trachoma scarring, conjunctival burns, chemical injuries, conjunctival aspergillosis, and diphtheritic conjunctivitis, among other diseases.
Mechanism: Contraction of the scar causes the posterior layer of the eyelid to shorten significantly more than the anterior layer, causing the lid margin to curl inward, resulting in scarring entropion.
(4) Spastic lid entropion
This is usually seen in the lower lid and is caused by spasm of the orbicularis oculi muscle. Mechanisms: This is commonly caused by acute inflammation, injury, or internal eye surgery (e.g., cataract extraction), as the stimulus causes reflex spasm of the orbicularis oculi muscle, especially the orbicularis oculi fibers near the lid margin, resulting in inward curling of the lid margin. Because the lower lid is thin and narrow, spasms are more likely to occur, while the upper lid is wider and inversion is less likely to occur. This type of entropion is mostly transient and most can disappear on their own once the stimulus disappears.
Clinical presentation
When examining lower lid impingement, the patient is asked to gaze downward to easily detect if the lashes are touching the cornea.
Patients often experience pain, eye redness, tearing, photophobia, persistent foreign body sensation, and increased eye discharge. Children are mostly reluctant to raise their heads and photophobic to cooperate with flashlight or slit lamp examination. Under the long-term rubbing of eyelashes, conjunctival congestion, punctate or diffuse damage to corneal epithelium or partial detachment of corneal epithelium, superficial corneal clouding, corneal neovascularization, corneal vascular opacity, corneal epithelial thickening, corneal epithelial keratosis, corneal ulceration, and corneal white spots lead to vision loss or even blindness in severe cases.
Complications
1. Inflammation of the conjunctiva: Because of the repeated stimulation of the conjunctiva and cornea by the eyelashes, conjunctivitis is more difficult to cure and often tends to recur, with tearing and secretions often appearing. When the inflammation of the conjunctiva is repeated and does not heal for a long time, some patients develop conjunctival scarring and a few develop local lid adhesions.
2. Changes in the cornea: impingement can cause punctate or diffuse damage to the corneal epithelium, detachment of the corneal epithelium, superficial corneal clouding, corneal vascular opacity, corneal epithelial keratosis, corneal ulcers, corneal white spots, which in turn affects vision.
3. Other: In addition to keratoconus, astigmatism can also affect vision, and in children, astigmatism can also cause amblyopia in some cases.
Differential diagnosis
1. Double row of eyelashes: An abnormality in which one row or part of the eyelashes grows at or slightly behind the opening of the lid gland.
2. Disorganized eyelashes or disorganized eyelash growth: Eyelashes that originate from the lid gland capsule and grow in a disorganized direction, most often in prolonged scarring conjunctivitis.
Treatment
1. For the treatment of impaired eyelashes in infants and children.
Some infants and children are fat, have flat nasal roots and are not full, and some have lower eyelid redundancy or joint canthus, which can cause lower eyelid impingement or lower eyelid entropion, which can heal on its own with age. Since infants’ eyelashes are generally small and soft, irritation is usually not obvious and surgery can only be considered when conservative treatment is ineffective, usually after the child is 3 years old. In some children, congenital entropion often disappears on its own as the nasal bridge develops, so there is no urgency to operate.
If, at the age of 5 to 6 years, the eyelashes are severely irritating the cornea and there is a lot of tearing, surgery may be considered. Younger children can have suture correction, which uses the force of suture pulling to pull the lid margin outward. This method is simple, has short general anesthesia, and is safe, but is prone to recurrence, with some patients relapsing after months or years. For older patients with severe entropion, partial excision of the lower eyelid skin and orbicularis muscle is possible. This procedure has a higher success rate and long-lasting results, but requires a lower eyelid bag incision or an upper eyelid blepharoplasty incision. Most parents of children who are afraid of “surgery” are more likely to accept sutures as a “stopgap” solution to alleviate the irritation of the impingement.
2. For adults with a small number of localized impingement without eyelid entropion, the following treatment methods are commonly used.
(1) Plucking: When the number of ingrown eyelashes is small, they can be plucked directly with eyelash tweezers. The eyelashes that grow again will be thicker and harder and irritate the cornea, so plucking is only a last resort when there is no other way to remove them, or when other methods have failed.
(2) Electrolysis: Electrolysis destroys the hair follicle and plucks it out, sometimes it needs to be repeated several times to achieve the desired effect, with a success rate of about 10-20%.
(3) Cryotherapy: can relieve numerous impingements, potential complications are: pigment loss of the skin, postoperative lid margin cut, damage to the lid gland and effect on the stability of the tear film.
(4) Laser treatment: laser detachment, which is effective for a few scattered distributions of impingement.
(5) Surgical excision of follicles under direct microscopic view: the follicles can be removed under direct microscopic view; if the number of impingement is high, wedge excision or anterior lamellar excision is effective for localized clusters of impingement that cannot be treated by other methods.
3. For patients with a high number of ingrown eyelashes and with eyelid entropion, the following surgical methods are commonly used.
(1) Upper lid buried suture method to correct entropion: This method is suitable for young patients with mild upper lid entropion with thin upper lid skin, no laxity, not much subcutaneous fat, and inconspicuous medial canthus.
(2) Lower lid suture pressure tube method for correction of lower lid entropion with impingement: also known as lower fornix skin suturing, this is suitable for some congenital lid entropion, spastic lid entropion and degenerative lid entropion (see Figures 8,9).
(3) Cutaneous orbicularis oculi excision: suitable for adolescents with lower lid redundancy with entropion and some elderly with degenerative entropion. By excising the skin near the lid margin and the hypertrophic orbicularis oculi muscle, skin tension is increased, tension is enhanced, and the orbicularis oculi muscle is prevented from exceeding the lid margin, and the incision is closed with deep fixation.
(4) Chorioretinal shortening: suitable for degenerative entropion of the eyelid.
(5) Lid wedge resection (Hotz procedure): for impingement caused by scarring entropion, surgical excision of part of the hypertrophied lid plate, by which the position of the lid margin is restored, the inward pull of the lid conjunctiva and lid plate is released, and the abnormal state of the lid is corrected.
(6) Blepharotomy: Suitable for cases with eyelid deformity and non-significant hypertrophy, the principle of this procedure is to cut the lid plate from the inferior lid sulcus, release the traction of the scar, and suture ligation to restore the lid margin to its normal position.
(7) Lid Margin Gray Line Incision: For patients whose degree of entropion is inconsistent across the eyelid or for those who have had other surgical procedures and still have partial impingement that is not completely corrected.
Disease Care
Postoperative medication is usually changed every other day and stitches are removed in 7 days. Avoid eating spicy foods for one week after surgery. Pay attention to the cleanliness of the surgical wound to avoid wound infection. Eat nutritious and easily digestible food, as well as vitamin-rich vegetables and fruits, to promote wound healing. Pay attention to rest and avoid fatigue.
In children younger than 3 years old, the timing of surgery can be chosen based on the child’s symptoms and the degree of damage to the cornea and vision because of the softness of the eyelashes. If there is no damage to the cornea or vision, the condition is mild and the symptoms are not obvious, the child can be observed. You can see your doctor regularly for 3 months or 6 months for observation. If you experience sudden photophobia, tearing, eye redness, and increased discharge, it is possible that conjunctivitis has worsened or there is inflammation of the cornea, which requires prompt medical attention. If the damage to the cornea caused by impingement is more severe, surgical treatment with general anesthesia may be considered. In adult patients, surgery can be considered if non-surgical treatment is not effective. The main problems that can occur after surgical treatment are: recurrence of impingement, scarring of the eyelid skin and the appearance of “double eyelids” on the lower lid, and incomplete correction of impingement after surgery for complex refractory impingement. However, with the advancement of technology, modern techniques for the correction of impingement will keep these problems to a minimum. Eyelid skin scarring usually fades, or disappears, after 3 to 6 months. It usually takes 3 months after the surgery for the eyelid skin and tissue to gradually swell and slowly return to natural.