Distichiasis is defined as a second row of eyelashes arising from which location?

Distichiasis is defined as a second row of eyelashes arising from which location?

• A. Trichiasis
• B. Dermatochalasis
• C. Distichiasis
• D. Blepharitis

Answer: (C)

Distichiasis means there is a second row of eyelashes that actually emerges from the openings of the meibomian glands along the posterior margin of the eyelid. These lashes originate from the back edge of the lid (the tarsal/posterior lid margin), rather than from the normal lash line. Because they sit closer to the ocular surface, they can rub against the cornea or conjunctiva and cause irritation or keratopathy. This is what sets it apart from trichiasis, where misdirected lashes come from the usual lash border, and from conditions like dermatochalasis or blepharitis, which involve excess skin or lid inflammation rather than an extra lash row arising from the meibomian gland orifices.

Distichiasis means there is a second row of eyelashes that actually emerges from the openings of the meibomian glands along the posterior margin of the eyelid. These lashes originate from the back edge of the lid (the tarsal/posterior lid margin), rather than from the normal lash line. Because they sit closer to the ocular surface, they can rub against the cornea or conjunctiva and cause irritation or keratopathy. This is what sets it apart from trichiasis, where misdirected lashes come from the usual lash border, and from conditions like dermatochalasis or blepharitis, which involve excess skin or lid inflammation rather than an extra lash row arising from the meibomian gland orifices.