This document summarizes several disorders of the eyelashes including trichiasis, metaplastic lashes, distichiasis, phthiriasis palpebrarum, madarosis, and poliosis. Trichiasis involves the misdirection of normal lashes toward the eye and can cause punctate epitheliopathy and corneal issues. Metaplastic lashes arise from meibomian gland orifices due to conditions like cicatrizing conjunctivitis. Distichiasis has a second row of lashes from the meibomian glands that may be treated by cryotherapy or surgery. Phthiriasis palpebrarum is an infestation by crab lice.

1. DISORDERS OF LASHES
1. Trichiasis
2. Metaplastic lashes
3. Distichiasis
4. Phthiriasis palpebrarum
5. Madarosis
6. Poliosis

2. Trichiasis
Signs Complications
• Posterior misdirection of normal lashes • Inferior punctate epitheliopathy
• Most frequently affects lower lid • Corneal ulceration and pannus

3. Treatment Options for Trichiasis
1. Epilation - but recurrences within few weeks
2. Electrolysis - but frequently repeated treatments required
3. Cryotherapy - for many lashes
4. Laser ablation - for few scattered lashes
5. Surgery - for localized crop resistant to other methods

4. Metaplastic lashes
Signs Causes
Aberrant lashes arising from meibomian Cicatrizing conjunctivitis (ocular pemphigoid,
gland orifices Stevens-Johnson, chemical burns)

5. Distichiasis
Signs Treatment
• Second row of lashes arising • Division into anterior and posterior
from meibomian gland orifices lamellae
• Congenital • Cryotherapy to posterior lamella
• Occasionally dominantly inherited • Reapposition of lamellae

6. Phthiriasis palpebrarum
• Infestation of lashes by pubic crab louse and its ova (nits)
• Typically affects children in poor hygenic conditions
Lice gripping base of lashes Nits and empty shells adhere to base of lashes
Treatment - removal, destruction and delousing

7. Madarosis
Decrease in number or complete loss of lashes
Local causes
• Chronic anterior
lid margin disease
• Infiltrating tumours
• Burns, radiotherapy
or cryotherapy
Systemic causes
• Generalized alopecia
• Myxoedema
• SLE
• Syphilis
• Leprosy
Following removal

8. Poliosis
Premature localized whitening of hair
Ocular associations
• Chronic anterior blepharitis
• Sympathetic ophthalmitis
Systemic associations
• Vogt-Koyanagi-Harada
syndrome
• Waardenburg syndrome