Analysis of blink dynamics in patients with blepharoptosis

Abstract

Owing to the rapid movements of the human upper eyelid, a high-speed camera was used to record and characterize voluntary blinking and the blink dynamics of blepharoptosis patients were compared to a control group. Twenty-six blepharoptosis patients prior to surgery and 45 control subjects were studied and the vertical height of the palpebral aperture (PA) was measured manually at 2 ms intervals during each blink cycle. The PA and blinking speed were plotted with respect to time and a predictive model was generated. The blink dynamic was analysed in closing and opening phases, and revealed a reduced speed of the initial opening phase in ptotic patients, suggesting intrinsic muscle function change in ptosis pathogenesis. The PA versus time curve for each subject was reconstructed using custombuilt parameters; however, there were significant differences between the two groups. Those parameters used included the rate of closure, the delay between opening and closing, rate of initial opening, rate of slow opening (nonlinear function) and the 'switch point' between those two rates of opening. The model was tested against a new group of subjects and was able to discriminate ptosis patients from controls with 80% accuracy.

Videographic Analysis of Blink Dynamics following Upper Eyelid Blepharoplasty and Its Association with Dry Eye

“…Previous studies have shown this noninvasive videography technique to be a reliable and accurate method of measuring blink dynamics. 11 , 16 …”

Blinking characterization from high speed video records. Application to biometric authentication

“…Traditionally, the eye blink was assessed by procedures requiring the application of electrodes to monitor the OO electromyographic activity and get the EOG signal [ 20 – 26 ], or the use of direct magnetic search coil technique [ 27 – 30 ]. Nevertheless, contact-free recording procedures such as photo or video, that permit a quantitative assessment for eye movement during blinking without interfering with the subject, have also been used [ 2 , 3 , 13 , 17 , 18 , 31 – 47 ].…”

Development of a Non-Invasive Blink Reflexometer

“…The image capture rate used in this study is lower than what has been previously used [9] , [10] for eyelid tracking (600 fps). Despite the lower capture rate, the software was successfully able to locate the eyelids in each frame and track excursion.…”

“…Concurrently, processing power has increased making analysis of the thousands of image frames recorded at high frame rates feasible. High-speed image capture has been successfully employed to record and measure eyelid location during a single, voluntary blink in both healthy subjects [9] and in patients with blepharoptosis [10] . However, to the authors’ knowledge, no study has used high-speed image capture to study reflexive blinks.…”