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Chapter 15 116 Table 15-1 Classification of Ptosis Levator maldevelopment (dysmyogenic) ptosis • Simple (defect isolated to levator muscle) Aponeurotic ptosis (dehisced or disinserted aponeurosis secondary to the following) • Age • With superior rectus muscle weakness • Cataract or other ocular surgery • Blepharophimosis syndrome • Congenital fibrosis of the extraocular muscles Myogenic (myopathic) ptosis • Oculopharyngeal dystrophy • Chronic progressive external ophthalmoplegia • Muscular dystrophy • Myasthenia gravis • Trauma to the muscular levator Neurogenic ptosis • Local blunt trauma • Blepharochalasis • Chronic edema (Graves’ disease, allergy, etc) Mechanical ptosis • Excess lid weight (lid or orbital mass) • Scarring Pseudoptosis • Due to lack of posterior eyelid support • Due to hypotropia • Oculomotor nerve palsy (third nerve) • Due to dermatochalasis • Misdirected oculomotor nerve regeneration • Due to globe malposition • Marcus-Gunn jaw-winking ptosis • Horner’s syndrome • Ophthalmoplegic migraine Adapted from Rathbun JE. Eyelid Surgery. Boston, MA: Little, Brown; 1990:203. Table 15-2 Table 15-3 Amount of Ptosis Amount of Ptosis (mm) <2 Levator Muscle Function Classification Levator Muscle Function (mm) Classification Mild 15 Normal 3 Moderate >8 Good >4 Severe 5 to 7 Fair <4 Poor Surgical Procedure Step 1 Step 4 After sterile skin preparation and sterile draping, upper eyelid just above the lash line, and the lid is placed on traction. This is done after the eyelid incision is carried to the tarsus so as to not distort the various layers of the anterior lamella. the upper eyelid crease is marked at the desired height so as to be symmetric with the opposite upper eyelid crease. Step 5 Step 2 Local anesthesia is injected subcutaneously along Step 3 Step 6 The skin is incised along the marked eyelid crease with a blade. The incision is made deeper through the orbicularis muscle to expose the superior border of the tarsus from medial to lateral with scissors (Figure 15-1). The orbicularis muscle is dissected inferiorly 3 to 4 mm to expose the superior tarsus and approximately 10 mm superiorly to expose the levator aponeurosis and the orbital septum. the eyelid crease and subconjunctivally along the superior border of the tarsus. A 4-0 silk traction suture is placed centrally in the At the medial and lateral ends of the tarsus, scissor incisions are made through the remaining eyelid at the edge of the tarsal border (Figure 15-2).