Modeling upper eyelid kinematics during spontaneous and reflex blinks.

To test a mathematical model for measuring blinking kinematics. Spontaneous and reflex blinks of 23 healthy subjects were recorded with two different temporal resolutions. A magnetic search coil was used to record 77 blinks sampled at 200 Hz and 2 kHz in 13 subjects.

The relationship between two types of upper eyelid movements: saccades and pursuit.

Purpose: To establish the relationship between upper eyelid saccades and upper eyelid pursuit movements.

Methods: Upper eyelid saccades and periodic sinusoidal upper eyelid pursuit movements were recorded in a sample of controls and patients with Graves upper eyelid retraction. A video-computerized system was used to register both types of movements that accompanied 60 degrees of eye rotation across the upper and lower hemifields.

Effect of age on upper and lower eyelid saccades.

To study the effect of age on the metrics of upper and lower eyelid saccades, eyelid movement of two groups of 30 subjects each were measured using computed image analysis. The patients were divided on the basis of age into a younger group (20-30 years) and an older group (60-91 years). Eyelid saccade functions were fitted by the damped harmonic oscillator model.

Upper and lower eyelid saccades describe a harmonic oscillator function.

Purpose: To determine whether experimentally measured upper and lower eyelid saccades can be fitted to a mathematical function.

Methods: A charge-coupled device video camera connected to a personal computer was used to record upper and lower eyelid saccades accompanying 20 degrees and 40 degrees of vertical eye rotation in 19 normal adult subjects. Movement analysis was performed with software that calculated the center of a blue spot in each frame.

The geometrical basis of the eyelid contour.

Purpose: To derive a two-dimensional, frontal-view model of eyelid contour.

Methods: Observational study. Palpebral fissure images of 110 normal subjects were acquired with a charge-coupled device camera and processed with National Institutes of Health Image software on a Macintosh computer.

Quantitative study of the effect of dacryocystorhinostomy on lacrimal drainage.

Using scintigraphy, we have studied the lacrimal drainage from the conjunctival sac of normal subjects and patients who have undergone dacryocystorhinostomy. A mathematical model of drainage was constructed that accurately described the complete activity curves for both groups. The initial rate of drainage was shown to be a relevant parameter to characterize drainage, and it was found to be different from normals to patients, indicating that the lacrimal pump mechanism is affected by dacryocystorhinostomy.