Trichiasis or eyelash disorder refers to inward misdirection of cilia or eyelashes (which rub against the eyeball) with normal position of the lid margin.
Pseudo trichiasis: The inward turning of lashes along with the lid margin (seen in entropion) is called pseudotrichiasis.
Common causes of trichiasis are: cicatrising trachoma, ulcerative blepharitis, healed membranous conjunctivitis, hordeolum externum, mechanical injuries, burns, and operative scar on the lid margin.
Clinical features of Trichiasis or eyelash disorder
These include foreign body sensation and photophobia. Patient may feel troublesome irritation, pain and lacrimation.
- Misdirected cilia one or more touching the cornea.
- Reflex blepharospasm and photophobia occur when cornea is abraded.
- Conjunctiva may be congested.
- Signs of causative disease viz. trachoma, blepharitis, etc. may be present.
These include recurrent corneal abrasions, superficial corneal opacities, corneal vascularisation and non-healing corneal ulcer.
Treatment of Trichiasis or eyelash disorder
A few misdirected cilia may be treated by any of the following methods:
- Epilation (mechanical removal with forceps): It is a temporary measure, as recurrence occurs within 3-4 weeks.
- Electrolysis:It is a method of destroying the lash follicle by electric current. In this technique infiltration anaesthesia is given to the lid and a current of 2 mA is passed for 10 seconds through a fine needle inserted into the lash root. The loosened cilia with destroyed follicles are then removed with epilation forceps.
- Cryoepilation:It is also an effective method of treating trichiasis. After infiltration anaesthesia, the cryoprobe (-20°C) is applied for 20-25 seconds to the external lid margin by double freeze-thaw technique. Its main disadvantage is depigmentation of the skin.
- Surgical correction: When many cilia are misdirected operative treatment similar to cicatricial entropion should be employed.
Congenital distichiasis (Fig. 15.17) is a rare anomaly in which an extra row of cilia occupies the position of Meibomian glands which open into their follicles as ordinary sebaceous glands. These cilia are usually directed backwards and when rubbing the cornea, should be electroepilated or cryoepilated.
Acquired distichiasis (metaplastic lashes) occurs when due to metaplasia and differentiation, the meibomian glands are transformed into hair follicles. The most important cause is late stage of cicatrizing
conjunctivitis associated with chemical injury, Stevens-Johnson syndrome and ocular cicatricial pemphigoidMadarosis
Madarosis refers to partial or complete loss of eyelashes.
Causes can be local or systemic:
- causes of madarosis include chronic blepheriris, cicatrizing conjunctivitis, and complication of cryotherapy, radiotherapy or surgery done for any eyelid lesion.
- Systemic causes of madarosis are alopecia (patchy, totalis/universalis), psoriasis, hypothyroidism and leprosy.
Image Source : Canadian Association of Optometrists