A Histologic Analysis of Tissue Excised During Mullerectomy for Blepharoptosis Repair

Abstract

 

Purpose

 

There has been recent discussion in the literature regarding the anatomical tissues excised during blepharoptosis repair via the posterior approach involving muller’s muscle resection. The goals of this study were to confirm on histopathology the exact tissues excised, evaluate the presence, if any, of levator complex, and correlate with the clinical results.

 

Methods

 

A retrospective chart review was performed on 5 patients that underwent a unilateral mullerectomy procedure by a single surgeon over a one-year period. Pre- and postoperative Marginal Reflex Distance-1 (MRD1) measurements were analyzed. All patients demonstrated good upper eyelid elevation to 2.5% phenylephrine testing. Hering’s phenomenon was documented in all patients. A Putterman's mullerectomy with meticulous technique was performed on all patients. The excised tissue was examined with hematoxylin and eosin (H&E) stain, 2 cytochemical stains (Masson’s trichrome stain and Verhoeff’s elastic stain), and 2 immunohistochemical stains (desmin and smooth muscle actin).

 

Results

 

All 5 patients (100%) achieved the desired upper eyelid margin on the operated side, with an average MRD1 correction of 2.5 mm. None of the patients suffered from lagophthalmos or dry eye syndrome. The presence of conjunctiva and 2 sandwhiched layers of organized smooth muscle was confirmed in all specimens. Trichrome stain demonstrated the absence of collagen bundles anterior to Muller's muscle confirming the lack of levator aponeurosis. Our findings also showed a fibrous connective tissue network between Muller's muscle and the palpebral conjunctiva. No skeletal muscle was identified.

 

Conclusions

 

Muller’s muscle resection is an effective and predictable procedure for the correction of mild to moderate ptosis in eyelids that respond clinically to phenylephrine testing. Histologic correlation demonstrated the absence of the levator aponeurosis complex in our surgical specimens. This suggests that the mechanism of repair in our technique can be attributed to the vertical shortening of the posterior eyelid by the mere resection of muller’s muscle.

 

 

Figure 1: Gross surgical specimen from our mullerectomy procedure.

 

 

Figure 2: Masson trichrome stain. The lack of blue staining centrally confirms the absence of levator aponeurosis in our surgical specimens.

 

Keywords: 638 pathology: human • 526 eyelid