Abstract
Purpose: :
Ptosis is a classic component of Horner Syndrome and results from interruption of sympathetic innervation to Muller’s muscle. Due to denervation hypersensitivity this muscle displays altered response to phenylephrine (PE) testing, an established diagnostic tool for operative planning. Given this change in baseline physiology, we sought to investigate the difference of unilateral and bilateral PE testing in such patients and the efficacy of Muller’s Muscle-Conjunctiva Resection (MMCR) in cases of both unilateral and bilateral repair.
Methods: :
Review of ptosis cases due to Horner Syndrome from a single practice between 1996 and 2011. Pre and post-operative objective measurements of ptosis severity were obtained from charts. The degree of ptosis was ascertained by the marginal reflex distance-1 (MRD1), the distance between the pupillary light reflex and the upper eyelid margin. The MRD1 was also measured following instillation of 10% PE in two stages - initially in the pathologic eye and subsequently instilled in both eyes. Patients underwent MMCR, with degree of resection determined by response to PE testing. Final outcome measures were the final degree of asymmetry and the predictability of PE testing (both unilateral and bilateral instillation). Asymmetry was deemed to be significant if over 1mm.
Results: :
Seven patients with ptosis derived from Horner were found. All underwent MMCR correction. 4/7 patients underwent bilateral correction secondary either to poor asymmetry following PE testing or due to coexisting low MRD1 in the non-Horner eye . The average pre-op MRD1 was -0.1mm in the ptotic eye with an average asymmetry of 2.1mm. PE instillation raised the ptotic lid on average of 3.1mm (single instillation) and 3.6mm (bilateral instillation), and dropped the contralateral lid 1mm (single) and raised it 1.6mm (bilateral). PE testing resulted in lid asymmetries of 1.9 mm (single) and 0.7mm (bilateral). Average resection was 8.5mm. Final post-operative MRD1 change was on average 4.0mm in the ptotic lid with an average asymmetry of 1.1mm. 3 of 7 patients had final asymmetry exceeding 1mm (2 unilateral corrections and 1 bilateral).
Conclusions: :
3 of 7 patients had final post-MMCR asymmetry that exceeded 1mm, but overall measures in the series showed significant post-op improvement (p=0.034). 2 of these patients had the largest asymmetry with bilateral PE testing, suggesting a possible predictive value for this test. There was a variable response amongst patients in both single eye and bilateral PE testing. Difficulty in predicting post-operative symmetry with both unilateral and bilateral repair may be a function of the altered sympathetic pharmacologic response in these patients.
Keywords: eyelid • clinical (human) or epidemiologic studies: outcomes/complications • anatomy