Abstract
Purpose :
To evaluate the diagnostic efficacy of the ice test after fatigue induction in the evaluation of ptosis in myasthenia gravis
Methods :
A retrospective observational study was conducted including 26 patients with ptosis related to MG and 30 patients with ptosis not related to MG who performed the ice test after fatigue induction. All patients underwent the ice test after fatigue induction by sustained upgaze for 2 minutes. The margin reflex distance of the upper eyelid (MRD) was measured before (MRDa) and immediately after sustained upgaze (MRDb) in the eye with more severe ptosis, and finally after 2-minute application of ice on the eyelids (MRDc). The ice test was judged positive if there was an improvement of at least 2.0 mm of MRD after the ice test. The accuracy of results was compared between the conventional ice test (MRDc-MRDa) and after fatigue induction (MRDc-MRDb).
Results :
After the conventional ice test, the sensitivity and specificity of the test were 38.5% and 100%, respectively. After fatigue induction, the sensitivity and specificity of the ice test were 65.4% and 96.7%. In subgroup analysis of patients with a pretest MRD of ≥ 0 mm, the sensitivity of the ice test was more than twofold higher after fatigue induction (62.5%) compared to the conventional test (25.0%).
Conclusions :
The sensitivity of the ice test significantly increased after fatigue induction, particularly in patients with a pretest MRD of ≥ 0 mm. This implies the benefit of fatigue induction before performing the ice test in patients with mild or subtle ptosis related to ocular myasthenia gravis.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.