Quantitating the change in upper eyelid position during downgaze.

Objective: To derive normative data on eyelid position in primary gaze, upgaze, and downgaze in subjects of various ages.

Methods: Upper eyelid margin to corneal light reflex distance (uMRD), lower eyelid to corneal light reflex distance (IMRD), and vertical interpalpebral fissure (IPF) measurements were obtained on 50 healthy subjects.

Results: In downgaze, a mean decrease of 1.0 mm uMRD (P < 0.001) and 2.3 mm IPF (P < 0.001) was noted. Linear regression analysis demonstrated that older subjects tended to have a greater decrease in uMRD on downgaze (P = 0.012).

Conclusions: Decrease in upper eyelid position on downgaze is a common phenomenon. Increased blepharoptosis on downgaze noted in patients with acquired blepharoptosis may largely reflect normal physiologic processes.