INTRODUCTION: To evaluate striated skeletal muscle fibers (upper eyelid levator muscle) in specimens taken from conjunctivo-mullerectomy surgery and correlate the surgical response of elevation greater than 2 mm in this surgery.
CASE PRESENTATION: Histopathological analysis of 20 excised conjunctivo-mullerectomy fragments for treating involutional ptosis of any magnitude with a 10% positive and satisfactory phenylephrine test to check for skeletal muscle fibers.
RESULTS: All analyzed tissue samples only had conjunctiva and smooth muscle tissue. We attest to the absence of striated muscle fibers in these samples.
CONCLUSION: There are no upper eyelid levator muscle fibers in the excised tissue in conjunctivo-mullerectomy surgery. The surgical response of elevation greater than 2 mm in this surgery may only be due to the closeness of the upper eyelid levator muscle to the superior border of the tarsal plate.
