Distichiasis (Double Eyelashes): Symptoms, Causes, Treatment

What are the symptoms of distichiasis?

Distichiasis is a rare genetic disorder characterized by an extra row of eyelashes (cilia) that emerge from the Meibomian gland orifices along the eyelid margin. These additional eyelashes can grow inwards towards the eye, causing irritation and other symptoms. Common symptoms of distichiasis include:

1. Irritation: The most common symptom of distichiasis is irritation of the eye due to the abnormal eyelashes rubbing against the cornea (the clear front surface of the eye) or the conjunctiva (the thin, clear membrane covering the white part of the eye).
2. Foreign Body Sensation: Individuals with distichiasis may experience a sensation of having a foreign body in the eye, often due to the presence of the extra eyelashes.
3. Tearing: Excessive tearing (epiphora) can occur as a result of the irritation caused by the abnormal eyelashes.
4. Corneal Abrasions: In some cases, the abnormal eyelashes can scratch the cornea, leading to corneal abrasions or ulcers. This can cause pain, redness, and sensitivity to light.
5. Corneal Opacity: Chronic irritation and corneal abrasions from distichiasis can lead to corneal scarring and opacity, which can affect vision.
6. Conjunctivitis: Inflammation of the conjunctiva (conjunctivitis) can occur secondary to the irritation caused by the abnormal eyelashes.
7. Photophobia: Sensitivity to light (photophobia) may occur due to the corneal irritation and inflammation associated with distichiasis.
8. Blepharospasm: Involuntary spasms of the eyelid muscles (blepharospasm) can occur as a protective mechanism in response to the irritation caused by the abnormal eyelashes.

Symptoms of distichiasis can vary in severity depending on the number and location of the extra eyelashes.

What are the causes of distichiasis?

Distichiasis is typically a genetic condition that is present from birth. It is caused by a mutation in the FOXC2 gene, which is involved in the development of the lymphatic system. This mutation leads to the abnormal development of the Meibomian glands in the eyelids, resulting in the growth of an extra row of eyelashes (distichia). These extra eyelashes can grow inwards towards the eye, causing irritation and other symptoms.

In some cases, distichiasis can be acquired later in life as a result of scarring or inflammation of the eyelids (such as from trauma, infection, or certain skin conditions). However, acquired distichiasis is less common than the congenital form.

Distichiasis can occur as an isolated condition or as part of a syndrome, such as lymphedema-distichiasis syndrome (LDS), which is characterized by distichiasis and lymphedema (swelling due to impaired lymphatic drainage). Other syndromes that may include distichiasis as a feature include blepharophimosis-ptosis-epicanthus inversus syndrome (BPES) and congenital ectropion uveae with glaucoma.

The inheritance pattern of distichiasis can vary. In some cases, it may be inherited in an autosomal dominant pattern, where a mutation in one copy of the gene is sufficient to cause the condition. In other cases, it may be inherited in an autosomal recessive pattern, where both copies of the gene must be mutated to cause the condition.

What is the treatment for distichiasis?

Treatment for distichiasis depends on the severity of symptoms and the impact on the eye. Mild cases may not require treatment, but if the extra eyelashes are causing irritation or other issues, treatment options may include:

1. Eyelash Removal: The most common treatment for distichiasis is to remove the extra eyelashes. This can be done using various methods, including manual plucking, cryotherapy (freezing), or electrolysis (destroying the hair follicle with an electric current).
2. Lubricating Eye Drops: Lubricating eye drops or ointments can help reduce irritation and soothe the eye.
3. Surgery: In more severe cases or if other treatments are ineffective, surgery may be necessary to remove the Meibomian glands or reposition the eyelashes.
4. Cauterization: Cauterization involves using heat or a chemical agent to destroy the hair follicles of the extra eyelashes, preventing them from growing back.
5. Laser Treatment: Laser therapy can be used to target and destroy the hair follicles of the extra eyelashes.
6. Regular Monitoring: Regular eye examinations by an ophthalmologist are recommended to monitor the condition and ensure that it does not lead to complications such as corneal abrasions or ulcers.

The choice of treatment depends on the individual’s symptoms, the extent of the distichiasis, and the presence of any complications. It’s important to consult with an eye care professional for an accurate diagnosis and appropriate treatment plan.