[Upper and lower eyelid position in different degrees of downgaze and upgaze]

To quantify the relation between eye and eyelids placement in different positions during downgaze and upgaze in healthy subjects.

The position of the eye and eyelids of 10 healthy individuals was quantified by palpebral fissure image processing with NIH Image software. Upper and lower mid-pupil margin distance was measured in 7 positions: -30, -20, -10, 0, +10, +20 and +30 degrees (positive signs correspond to upgaze and negative signs to downgaze) along vertical meridian.

The upper mid-pupil margin distance decreases in upgaze and even more in downgaze. The lower mid-pupil margin distance increases in upgaze and decreases in downgaze. About the palpebral fissure height, it gets larger in upgaze until 20 degrees and smaller in downgaze.

Our data showed that the interpalpebral fissure height varies with vertical meridian gaze amplitude and that considerations about mid-pupil margin distance must consider the amount of upgaze or downgaze.