Contralateral Mueller's muscle-conjunctiva resection: a therapeutic option in thyroid eye disease patients with unilateral eyelid retraction

Purpose: To evaluate pre- and post-operative marginal reflex distance 1 (MRD1) when conducting Mueller's muscle-conjunctiva resection (MMCR) on the normal eyelid of thyroid eye disease (TED) patients with unilateral eyelid retraction. Methods: This was a retrospective non-comparative case series. Medical records of TED patients with unilateral eyelid retraction, who underwent a contralateral MMCR from November 2015 to September 2017, were reviewed. Standard photographs of pre-operative, post-phenylephrine test and post-operative were measured for eyelid positions including MRD1, MRD2 and inter-palpebral fissure width. MMCR was indicated on the contralateral eyelid only in patients who had a cosmetically acceptable result from phenylephrine test and were willing to receive the operation on the normal eye. Results: Twelve TED patients who underwent MMCR on the normal eyelid were included in the study. Mean pre-operative MRD1 of retracted and normal eyelid were 5.7 mm (SD = 0.86) and 3.5 mm (SD = 0.65), respectively. Mean post-operative MRD1 of retracted and normal eyelid were 4.4 mm (SD = 0.76) and 4.1 mm (SD = 0.46), respectively. The asymmetry of MRD1 between eyes was significantly decreased from 2.1 mm (inter-quartile range (IQR) = 1.5-2.9 mm) pre-operatively to 0.3 mm (IQR = 0.1-0.7 mm) post-operatively (p = .002). None of these patients needed further eyelid correction surgery and there was no complication. Conclusions: In TED patients with unilateral eyelid retraction, using phenylephrine test on their normal eyes should be initiated. If eyelid position was satisfactorily equalized, performing MMCR on the normal eyelid is considered an effective alternative treatment with a predictable outcome.