Junhee Lee, M.D., Jeffrey
Nerad, M.D., Keith Carter, M.D., and Randy Kardon, M.D.
Purpose: To evaluate
the movement parameters of the levator palpebrae superioris in cases
of involutional blepharoptosis.
Methods: An infrared
camera with a 1000 Hertz sampling rate was used to trace the time course
of pupil occlusion by the upper eyelid during blinks. This allowed calculation
of velocity and acceleration of the eyelid margin as it travelled over
the pupil. A 60 Hertz video camera was used to record the movement characteristics
of the upper eyelid during maximal excursions from downgaze to upgaze.
Eyelids with involutional blepharoptosis were compared to age-matched
control eyelids, and/or normal eyelids of opposite eyes.
Results: Data obtained
by 60 Hz video camera indicated a significant slowing of upward eyelid
excursion in patients with involutional blepharoptosis. Data obtained
by 1000 Hz infrared camera also demonstrated slowing of the up-phase
of spontaneous blinks in ptotic patients, although the data did not
show statistical significance.
Conclusions: Although
generally regarded as a disinsertion or stretching of the attachments
of the levator palpebrae superioris to the tarsus, involutional blepharoptosis
may have a significant contribution from actual muscular weakening.
