UNILATERAL CONGENITAL PTOSIS - COMPENSATORY HEAD POSTURING AND AMBLYOPIA

Patients with unilateral congenital ptosis often adopt chin elevation to maintain fusion. This compensatory head posturing has been consider ed a sign of fusion, thus indicating a low risk for amblyopia. To eval uate this sign, we reviewed the charts of 11 preverbal children with u nilateral congenital ptosis who had straight eyes and appropriate comp ensatory head posturing to maintain binocular vision. Four additional patients with unilateral ptosis and no compensatory head posturing wer e tested for comparison. All patients had undergone an examination and had been tested by pattern Visual Evoked Potential (VEP) under chlora l hydrate sedation. Five of the 11 patients with compensatory head pos turing were found to be amblyopic, three moderately so and two severel y affected. The four patients without compensatory head posturing were amblyopic. It is our hypothesis that compensatory head posturing allo ws peripheral fusion even when significant amblyopia is present. Addit ionally, the clinical sign of a compensatory head turn to maintain bin ocular vision does not rule out the presence of significant amblyopia.