Abstract ID: 26-615
Is there actually a Müller muscle included in a Mullerectomy? A histology result from MMCR.
Author: Martina Paradzik Simunovic Base Hospital / Institution: University Hospital Centre Split, Croatia
Presentation Type: ePoster Presentation
Purpose
Müller muscle–conjunctival resection (MMCR) is an effective surgical technique for selected cases of blepharoptosis with good levator function and a positive phenylephrine test. Since its introduction by Putterman in 1975, the procedure has gained widespread acceptance, although its exact mechanism of action remains debatable. The purpose of this study was to evaluate the clinical and histological findings in a series of patients with blepharoptosis.
Methods
This single-center case series included 16 patients with a positive phenylephrine test, comprising six cases of unilateral ptosis and ten cases of bilateral ptosis. Excised specimens were histopathologically analyzed to identify the presence of muscle and/or conjunctival tissue. Preoperative and postoperative marginal reflex distance 1 (MRD1) measurements were compared to evaluate functional improvement and to assess any correlation with tissue composition.
Results
Among the 26 analyzed specimens, 16 (62%) contained smooth muscle, whereas no samples demonstrated striated muscle. The remaining 10 specimens (38%) consisted solely of conjunctival tissue. The mean preoperative MRD1 was 1.22 ± 0.78 mm, which improved to a mean postoperative MRD1 of 2.48 ± 0.90 mm, indicating significant functional improvement.
Conclusion
Our findings support MMCR as a highly effective procedure with a short learning curve for selected cases of blepharoptosis characterized by good levator function and a positive phenylephrine test, complemented by histological evaluation. Particulary, functional improvement was also observed in the 38% of patients whose specimens contained conjunctival tissue alone following MMCR. This outcome may be explained by the mechanical effect of posterior lamellar shortening, either through plication or anterior advancement of the levator aponeurosis. Further prospective studies involving larger patient cohorts are required to better elucidate the relationship between histological findings and the precise mechanism of action underlying MMCR.