Lm. Hamed et Am. Lessner, FIXATION DURESS IN THE PATHOGENESIS OF UPPER EYELID RETRACTION IN THYROID ORBITOPATHY - A PROSPECTIVE-STUDY, Ophthalmology, 101(9), 1994, pp. 1608-1613
Background: Upper eyelid retraction in thyroid eye disease may be caus
ed by proptosis, levator and Muller's muscle infiltration with fibrosi
s or individual fiber enlargement, excessive sympathetic innervation,
abnormal adhesions between levator palpebrae muscle and surrounding ti
ssues, or fixation duress. Fixation duress refers to upper eyelid retr
action while fixating with an eye with inferior rectus muscle restrict
ion due to excessive simultaneous firing of the ipsilateral superior r
ectus and levator palpebrae muscles. Methods: The authors prospectivel
y examined six patients with strabismus and thyroid eye disease associ
ated with inferior rectus restriction and upper eyelid retraction in w
hom the eyelid retraction was suspected clinically to be a result of f
ixation duress. All six patients underwent recession of both inferior
recti ranging from 3 to 6.5 mm (mean, 4.5 mm) to improve the ocular mo
tility and alignment, reduce the diplopia, and mitigate the upper eyel
id retraction. Results: Reduction of upper eyelid retraction measured
as the preoperative versus postoperative difference in corneal light r
eflex - upper eyelid margin measurements was achieved in all patients
postoperatively, ranging from 1.5 to 5.5 mm (mean, 3.2 mm). Only one p
atient showed significant residual retraction to warrant consideration
of upper eyelid surgery. Conclusion: Fixation duress plays a signific
ant role in upper eyelid retraction of thyroid eye disease in a subset
of patients with restriction of the inferior rectus muscle. In this s
elected group of patients, the upper eyelid retraction may be reduced
or eliminated upon proper recession of the tight inferior rectus muscl
e(s).