Levator palpebrae superioris muscle: MR evaluation of enlargement as a cause of upper eyelid retraction in Graves disease.

Abstract

Sympathetic stimulation of the Müller muscle may be responsible for most of the medically reversible cases of eyelid retraction in patients with Graves disease. The authors studied 21 patients with class I Graves ophthalmopathy (GO), 32 patients with Graves disease without ophthalmopathy (GD), and 12 control subjects. T1-weighted spin-echo magnetic resonance (MR) imaging was performed with a 0.5-T superconducting system. The thickness of the levator palpebrae superioris muscle was determined from sagittal MR images. The thickness of the levator muscles in patients with GD did not differ from the thickness in control subjects, but the levator muscles in patients with GO were significantly thickened (P < .01). The thickness of the levator muscles in patients with GO was significantly greater than in those of patients with GD (P < .01). In 64 orbits of patients with GD, 3% of levator muscles were thickened. In 33 of 40 (83%) orbits of patients with GO presenting with upper eyelid retraction, the levator muscles were thickened. Sagittal MR imaging demonstrated thickening of the levator muscles in patients with persistent upper eyelid retraction. The authors conclude that a thickened levator muscle probably causes upper eyelid retraction in patients with GO.

Ocular Manifestations in Thyroid Eye Disorder: A Cross-Sectional Study from Nepal

“…Sympathetic stimulation of the Müller muscle may be responsible for most of the medically reversible cases of eyelid retraction in patients with Graves disease [23]. Similarly, the perioebital edema, conjuctival injection, proptosis, extraocular muscle restriction all are attributed to the inflammation of intraorbital fat as well as extraocular muscle.…”

Thyroid Eye Disease With Significant Levator Involvement and Ptosis

“…4 Previous articles have investigated levator involvement and have identified it as a possible explanation for eyelid retraction. Ohnishi et al 2 reported that 83% of patients with TED had enlargement of the levator palpebrae on MRI. Small 3 also showed that pathologically there was enlargement of levator muscle fibers in patients with TED.…”

“…Pathologic and radiographic studies revealed that although the inferior rectus is most commonly involved, every extraocular muscle, including the levator palpebrae, can be affected. 2,3 Previous studies investigating the etiology of eyelid retraction in TED have shown there to be involvement of the levator muscle as well; however, patients do not typically present with significant enlargement of this muscle. The case in this study is unique, in that the patient presented with a several year history of ptosis and severe involvement of the levator palpebrae seen on MRI and confirmed with incisional biopsy.…”

Normal and abnormal lid function

“…15.14) (Bartley and Gorman, 1995). The lid retraction is likely due, not only to physical enlargement of the LPS, but also to excessive neural stimulation of the LPS accompanying increased neural output to the superior rectus in an effort to overcome the mechanically induced elevation deficit from inferior rectus restriction (Ohnishi et al, 1993;Hamed and Lessner, 1994). Outward signs of orbital disease, including several eyelid signs, are helpful in establishing the orbital location of abnormal lid function.…”