Downgaze ptosis.

In involutional blepharoptosis, an abnormally low lid position in primary gaze is accompanied by increased lid excursion in downgaze. Described here are four patients with little or no ptosis in primary position but significant and symptomatic obstruction of the visual axis in downgaze only. All responded well to minimal aponeurotic advancement with sufficient elevation of the lids in downgaze to allow reading but with little or no discernible change of the lids in primary position. This "downgaze ptosis," not previously described, may be an early stage of typical involutional ptosis.