Overview

Trichiasis is a disease that can disrupt normal eye function. To understand its severity, it is important to know how the eye functions to provide clear vision. 

Structure of the eye

The eye is a vital organ that allows us to see our surroundings, helping us navigate the world and protect ourselves from potential dangers. This spherical-shaped organ consists of numerous structures, each serving an important role.¹ These structures include:¹ 

• Eyelash
• Conjunctiva
• Cornea 
• Iris 
• Lens 
• Retina 

Eyelash 

Eyelashes are hair follicles that grow along the edge of our eyelids (eyelid margin), acting as a protective barrier that prevents debris like dust from entering the eyes. This is important as it reduces the risk of damage to the cornea.² They also help divert water and air from the eyes, minimising exposure to pathogens.²

Conjunctiva

The conjunctiva is a tissue that not only provides a physical barrier but also produces the mucus and water required for tear production.³ 

Tears are not just droplets that form when we cry; they help create the tear film, a protective, moisture-rich layer that coats the surface of the eye. The tear film is primarily known for lubricating the eye’s surface, allowing smooth eyelid movement. However, it also plays a crucial role in defending against pathogens and delivering oxygen and nutrients to the eye’s surface, as it lacks blood vessels.⁴ 

Cornea

The cornea is the transparent outer layer of the eye that not only allows light to enter but also protects the eye's internal structures.⁵ It is made up of five different layers, serving multiple functions, which include:⁵ 

• Epithelium - cells that prevent entry of debris or chemicals and take up the oxygen and nutrients required for the cells at the eye’s surface
• Bowman’s membrane - a thin, transparent collagen layer 
• Stroma - the thickest layer of water and collagen, which allows light to be refracted into the eye
• Descemet membrane - a thin layer of collagen fibres that anchors the endothelium to the overlying layers of the cornea⁶
• Endothelium - removes excess fluid from the stroma, which helps maintain the clarity of the cornea 

The internal structures - iris, lens, and retina 

The iris is a muscular structure that not only gives our eyes their colour but also controls the size of the pupil.⁷ 

The lens focuses the light entering the eye onto the retina.⁷ 

The retina contains photoreceptors that convert light into electrical signals, which are sent to the brain for processing, allowing us to perceive images and see⁷ 

What is trichiasis?

Trichiasis is a condition that causes your eyelashes to grow in the wrong direction, towards the eye’s surface.² 

It is caused by several different factors including:²

• Chronic inflammation of the eyelid 
• Physical or chemical injuries 
• Eczema 
• Eyelid tumours
• Other conditions such as:
  • Entropion - the eyelid margin turns inwards; commonly caused by the weakening of eyelid tendons as we age⁸ 
  • Ocular cicatricial pemphigoid disease - an autoimmune disease that attacks a part of the conjunctiva⁹
  • Vernal keratoconjunctivitis - recurrent inflammation of the conjunctiva¹⁰

Why is it important to treat trichiasis? 

Treating trichiasis is crucial because it can severely impair vision. When eyelashes grow inward toward the eye, they continuously disrupt the tear film and irritate the cornea, leading to discomfort and potential damage.² Over time, this irritation can cause scarring of the cornea, which may result in blindness.¹¹ This occurs because the cornea's healing process changes the highly organised arrangement of collagen in the stroma, causing it to become opaque.¹² Since the cornea is essential for allowing light to pass through, refracting light, and absorbing oxygen and nutrients, it is crucial to address trichiasis early to prevent long-term eye complications. In this article, we will be exploring:

• The treatment options
• The different surgical options 
• A new treatment option 
• What to expect before surgery?
• Postoperative care

Treatment options 

The treatment for trichiasis can be either temporary or permanent. The NHS offers several treatment options, including:²

• Tweezing/plucking (temporary)
• Cryosurgery/cryotherapy 
• Electrolysis 
• Surgical repositioning

Surgical options

The surgical options include cryosurgery, electrolysis, and surgical repositioning.

Cryosurgery 

Cryotherapy works by using low temperatures to destroy the hair follicle.¹⁴ This is possible as the cryotherapy tools are stored in liquid nitrogen, which has a boiling point of -196 °C.¹⁵ It is important that the follicle freezing is performed adequately to prevent recurrence.¹⁶

The NHS states that cryotherapy typically causes no skin wounds and that scarring is uncommon. 

Electrolysis 

Electrolysis involves making a small incision in the eyelid to access the hair follicle, which is the root of the hair embedded deep within the skin. A controlled electrical current is then applied to the follicle, effectively destroying it to prevent further eyelash growth.¹⁷

The NHS states that electrolysis can cause bruising and swelling of the eye. There is also a risk of recurrence, which may require repeat treatments.

Surgical repositioning

There are different approaches to surgical repositioning. 

A temporary surgical procedure involves using a few stitches to help return the eyelid to its normal position.⁸ The NHS states that these stitches can result in bruising or scarring of the eyelid. 

Another surgical procedure that is recommended for trichiasis caused by entropion is tarsal rotation.¹³ This procedure involves turning the abnormal eyelid margin to ensure it is positioned so that the eyelashes are directed upward.¹³ 

New surgical technique 

Releasing Follicle Roots of Eyelashes (RFRE) is an innovative technique that involves making an incision in the eyelid to remove each misdirected hair follicle root and then reposition them correctly to promote proper lash growth.¹⁸ 

This case has not reported any recurrence so far, but further studies with more patients are needed to confirm these findings.¹⁸ 

What to expect before surgery?

Patients will receive proper preparation, including the administration of anaesthesia and the use of corneal shields (a plastic cover inserted like a contact lens) to protect the eye’s surface during surgery.¹³ 

Postoperative care 

What will happen after the surgery?

1. The operated eye will be covered with an eye patch
2. An overnight stay may be recommended to prevent accidental damage to the wound while sleeping
3. The eye patch will be removed the following day, and the area will be carefully cleaned and examined for any signs of infection
4. If the patient does not come in for follow-up on the first postoperative visit, they will be advised on how to clean and monitor the wound themselves²⁰ 

How to take care of the wound?

• Swelling is normal after surgery and will eventually go down, so there is no need to worry
• Always wash your hands thoroughly before touching your eyes to prevent infection
• Gently clean the operated eye using a cotton gauze and cooled, boiled water, starting from the area around the eye
• Avoid activities that expose you to dust or smoke, such as cooking over an open fire, as these can irritate the healing eye²⁰ 

When should you get your wound checked by a doctor?

• Signs of inflammation:
  • Swelling
  • Redness
  • Pain
  • Discharge
  • Fever
• Postoperative bleeding 
• Sharp or persistent pain 
• Eyelashes irritating the eye
• Incomplete eyelid closure²⁰

FAQs 

What is the most common cause of trichiasis in the UK? 

The most common cause is entropion, which typically occurs in adults.^8,18 

Can trichiasis fix itself? 

Unfortunately, trichiasis cannot fit itself. It is best to see a doctor who can find the cause of the misdirected eyelashes and then provide you with the best possible treatment plan. 

What is the difference between trichiasis and distichiasis? 

Trichiasis is the abnormal growth of eyelashes that typically emerges from the eyelid margin.² In contrast, distichiasis occurs when extra eyelashes grow in incorrect positions, usually just below the upper lashes or above the lower lashes, where the meibomian glands are located. Like trichiasis, distichiasis can also lead to irritation and corneal damage if the misdirected lashes rub against the eye.²¹ 

Why choose surgery over tweezing? 

Although surgical treatments have a chance of recurrence, they significantly reduce the frequency of eyelash regrowth. This can be beneficial as it minimises the need for plucking your eyelashes every two months.¹⁹ 

Summary 

Trichiasis occurs when eyelashes grow in the wrong direction, potentially causing corneal damage that can lead to blindness. Seeking treatment as early as possible is essential to prevent complications. Treatment options range from temporary to permanent solutions. More permanent treatments often involve surgical procedures such as cryotherapy, electrolysis, and surgical repositioning; however, there is still a chance of recurrence.