Ultrasound biomicroscopy of the levator aponeurosis in congenital and aponeurotic blepharoptosis.

Purpose: To evaluate and measure the thickness of the levator aponeurosis by ultrasound biomicroscopy in congenital dysmyogenic and aponeurotic blepharoptosis.
Methods: Forty-four upper eyelids of 22 patients who had unilateral blepharoptosis were evaluated by ultrasound biomicroscopy. The patients ranged in age from 13 to 69 years (mean, 35.4 +/- 20.2 years). Fourteen patients were male and 8 patients were female. Seven patients had congenital dysmyogenic blepharoptosis and 15 patients had aponeurotic blepharoptosis. Imaging was performed with a 50-MHz transducer. The thickness of the levator aponeurosis was measured centrally at the upper border of the tarsus.
Results: The levator aponeurosis was imaged in all eyelids except for one eyelid with aponeurotic blepharoptosis. The mean thickness of the levator aponeurosis was 0.39 +/- 0.10 mm in the ptotic eyelid and 0.42 +/- 0.09 mm in the control eyelid of the patients with congenital dysmyogenic blepharoptosis (p = 0.043). The mean thickness of the levator aponeurosis was 0.26 +/- 0.05 mm in the ptotic eyelid and 0.36 +/- 0.04 mm in the control eyelid of the patients with aponeurotic blepharoptosis (p = 0.001). The thickness of the levator aponeurosis was correlated with the palpebral fissure height (p = 0.013, r = 0.644) in aponeurotic blepharoptosis. The thickness of the levator aponeurosis was correlated with the levator function (p = 0.033, r = 0.795) in congenital dysmyogenic blepharoptosis.
Conclusions: The thickness of the levator aponeurosis can be measured with ultrasound biomicroscopy. The most common pathology in aponeurotic blepharoptosis is thinned-out aponeurosis. The levator aponeurosis of the ptotic eyelid is thinner than the normal eyelid in congenital ptosis.