APEA Pathophysiology – Eye, Ear, Nose & Throat (EENT) Practice Exam

The condition that involves drooping of the eyelid is ptosis. This condition occurs when the muscles responsible for lifting the eyelid are weak or damaged, leading to a position where the eyelid hangs lower than it should. Ptosis can affect one or both eyelids and may be congenital or acquired, often resulting from conditions affecting the levator muscle or the nerve that innervates it, such as oculomotor nerve palsy. Entropion refers to a condition where the eyelid turns inward, causing the eyelashes to rub against the eyeball, which can lead to discomfort and irritation. Ectropion is the opposite, where the eyelid turns outward, exposing the inner eyelid and potentially causing dryness and irritation of the conjunctiva. Strabismus, on the other hand, is a misalignment of the eyes, where one or both eyes do not properly align with the light and visual field. Each of these conditions has distinct presentations and underlying mechanisms, distinguishing them clearly from ptosis.