Trichiasis and Distichiasis
Trichiasis is an acquired condition in which eyelashes emerging from their normal anterior origin curve inward toward the cornea. It can be idiopathic or secondary to chronic inflammatory conditions such as mucous membrane pemphigoid, Stevens-Johnson syndrome, ocular graft-vs-host disease, blepharitis, or chemical burns. Most cases are probably the result of subtle cicatricial entropion of the eyelid margin.
Distichiasis is a congenital (often autosomal dominant) or acquired condition in which an extra row of eyelashes emerges from the ducts of meibomian glands. These eyelashes can be fine and well tolerated or coarser and a threat to corneal integrity.
Aberrant eyelashes and poor eyelid position and movement should be corrected. Aberrant eyelashes may be removed by mechanical epilation, electrolysis with a radiofrequency probe, or cryotherapy. Mechanical epilation is temporary because the eyelashes normally grow back in as few as 3 weeks. Electrolysis works well for removing only a few eyelashes; however, it may be preferable in younger patients for cosmetic reasons. Cryotherapy is still a common treatment for aberrant eyelashes, but freezing can result in eyelid margin thinning, loss of skin pigmentation, loss of adjacent normal eyelashes, and persistent lanugo (hairs), which may continue to abrade the cornea. Treatment at −20°C should be limited to less than 30 seconds to minimize complications. The preferred surgical technique for aberrant eyelashes due to marginal cicatricial entropion is tarsotomy with eyelid margin rotation. See BCSC Section 7, Oculofacial Plastic and Orbital Surgery, for additional discussion of trichiasis and cicatricial entropion.
Woreta F, Muñoz B, Alemayehu W, West SK. Three-year outcomes of the Surgery for Trichiasis, Antibiotics to Prevent Recurrence trial. Arch Ophthalmol. 2012;130(4):427–431.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.