What leads to the inward rotation of the eyelid margin in cicatricial entropion?

Cicatricial entropion is a condition characterized by the inward rotation of the eyelid margin, which can result in the eyelashes rubbing against the cornea, leading to discomfort and potential damage to the eye. The primary cause of inward rotation in cicatricial entropion is the presence of scar tissue that forms on the palpebral conjunctiva or the eyelid itself.

Scarification of the palpebral conjunctiva leads to thickening and contraction of the tissue, which effectively pulls the eyelid margin inward. This scarring often results from chronic inflammation, infection, or trauma, which alters the normal anatomy of the eyelid and causes it to turn inwards.

Although weakness of the ocular muscles, increased intraocular pressure, and thinning of the eyelid skin are factors that can affect eyelid position, they do not specifically lead to the structural changes resulting in cicatricial entropion. The hallmark feature is the fibrosis and contraction of the conjunctival tissue that results in the eyelid's inward turning. Thus, scarification is the most direct cause of this condition, making it the correct choice.