Eyelid retraction has numerous causes. Most notably eyelid retraction is caused by thyroid eye disease (TED), trauma, and postsurgical changes. The upper eyelid margin is typically measured at 3.5 to 4.5 mm above the center of the cornea. The lower eyelid margin is typically situated at the inferior border of the limbus. Eyelid retraction is a condition in which the upper eyelid margin is displaced superiorly or the lower eyelid margin is displaced inferiorly. Eyelid retraction may result in exposure keratopathy and disturbing ocular symptoms, including blurred vision, photophobia, foreign body sensation, burning, and reactive tearing. Eyelid retraction in TED is thought to be due to a combination of inflammation, fibrosis, and adrenergic stimulation of the eyelid retractors. Proptosis can also contribute to eyelid retraction. In the upper eyelid, factors responsible for eyelid retraction include (1) inflammation and fibrosis of the levator and Müller’s muscles, (2) adrenergic stimulation of Müller’s muscle, and (3) inflammation and fibrosis of the inferior rectus muscle, causing hypodeviation of the globe and compensatory overaction of the superior rectus–levator complex. In the lower eyelid, factors responsible for eyelid retraction include (1) inflammation and fibrosis of the inferior rectus muscle with consequent traction on its anterior extension, the capsulopalpebral fascia, which is the main lower lid retractor, and (2) adrenergic stimulation of the smooth muscle fibers within the lower lid retractor complex. A combination of eyelid retraction and proptosis in TED may result in ocular exposure with symptoms of ocular irritation, an undesirable cosmetic appearance, corneal erosion and infection, or (rarely) globe luxation. Mild exposure problems can be managed with topical lubricants. Guanethidine, a topical sympatholytic agent, is of limited usefulness in the management of eyelid retraction due to its variable efficacy and frequent ocular side effects, including irritation, hyperemia, photophobia, pain, edema, burning sensation, and punctate keratitis. It may be more tolerable if used in lower concentrations. Exposure problems in the inflammatory phase of the condition present a special challenge as surgical correction of eyelid retraction is best performed in the pos-tinflammatory, stable phase. Several reports have described using Botulinum toxin injections, 2.5 to 15 U, either subconjunctivally or percutaneously, just above the superior border of the tarsus.
Changes in horizontal strabismus after inferior rectus muscle recession with or without nasal transposition in thyroid eye disease: A retrospective, observational study
