History
Individuals with congenital distichiasis may have a family history. Distichiasis-lymphedema syndrome, an autosomal-dominant condition, results from mutations in FOXC2, a member of the forkhead/winged family of transcription factors. Other related findings may include congenital heart disease, webbing of the neck, and extradural spinal cysts. [1]
Individuals with acquired distichiasis may have a past history of chronic inflammation of the eyelids, including Stevens-Johnson syndrome, ocular cicatricial pemphigoid (OCP), trauma, chemical burns, and previous surgery.
Physical
Abnormal lashes from the meibomian gland orifices are noted on slit lamp examination.
The corneal epithelium should be evaluated at the slit lamp after instillation of fluorescein for any defects or abnormalities.
Causes
The congenital form of distichiasis is autosomal dominant with complete penetrance. [2, 3] The metaplasia of meibomian glands and abnormal growth of lashes from these glands, secondary to severe chemical burn, Stevens-Johnson syndrome, OCP, or chronic blepharoconjunctivitis, can cause acquired distichiasis.
Complications
In some cases, differentiation of acquired distichiasis from trichiasis may be difficult. In trichiasis, the lashes grow from the anterior lamella, not from the meibomian orifices (see following image). After lid reconstruction, this distinction may not be possible, especially if a skin graft was used.
This picture demonstrates distichiasis of the lower lid. From Principles and Practice of Ophthalmology by Jakobiec.
Entropion may be confused with distichiasis. The lids must be held in their proper position to evaluate the lashes. Careful examination of the lid anatomy and the lid position prevents the misdiagnosis.
Epiblepharon is a condition that is mostly present in children. In this condition, the lashes are not truly misdirected, but pushed by the fold of pretarsal skin against the globe.
Lid scar, chronic blepharoconjunctivitis, and cicatricial conjunctivitis are other conditions that can be confused with distichiasis.
Complications of surgical interventions are hemorrhage, infection, wound dehiscence, lid margin deformities, entropion or ectropion, and regrowth.
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This picture demonstrates distichiasis of the lower lid. From Principles and Practice of Ophthalmology by Jakobiec.
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This picture demonstrates distichiasis of the upper lid. From Ophthalmic Plastic Surgery: Prevention and Management of Complications by Dortzbach.
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This picture demonstrates the cryotherapy of the lower lid with distichiasis. From Ophthalmic Plastic Surgery: Prevention and Management of Complications by Dortzbach.
