Dataset Information

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 custom-built 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.

SUBMITTER: Mak FH

PROVIDER: S-EPMC4843668 | biostudies-literature | 2016 Mar

REPOSITORIES: biostudies-literature

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Analysis of blink dynamics in patients with blepharoptosis.

Mak Felix H W FH Harker Anthony A Kwon Kyung-Ah KA Edirisinghe Mohan M Rose Geoffrey E GE Murta Fabiola F Ezra Daniel G DG

Journal of the Royal Society, Interface 20160301 116

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 ...[more]

PMID: 26962027

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Project description:IMPORTANCE Facial paralysis remains one of the most challenging conditions to effectively manage, often causing life-altering deficits in both function and appearance. Facial rehabilitation via pacing and robotic technology has great yet unmet potential. A critical first step toward reanimating symmetrical facial movement in cases of unilateral paralysis is the detection of healthy movement to use as a trigger for stimulated movement. OBJECTIVE To test a blink detection system that can be attached to standard eyeglasses and used as part of a closed-loop facial pacing system. DESIGN, SETTING, AND PARTICIPANTS Standard safety glasses were equipped with an infrared (IR) emitter-detector unit, oriented horizontally across the palpebral fissure, creating a monitored IR beam that became interrupted when the eyelids closed, and were tested in 24 healthy volunteers from a tertiary care facial nerve center community. MAIN OUTCOMES AND MEASURES Video-quantified blinking was compared with both IR sensor signal magnitude and rate of change in healthy participants with their gaze in repose, while they shifted their gaze from central to far-peripheral positions, and during the production of particular facial expressions. RESULTS Blink detection based on signal magnitude achieved 100% sensitivity in forward gaze but generated false detections on downward gaze. Calculations of peak rate of signal change (first derivative) typically distinguished blinks from gaze-related eyelid movements. During forward gaze, 87% of detected blink events were true positives, 11% were false positives, and 2% were false negatives. Of the 11% false positives, 6% were associated with partial eyelid closures. During gaze changes, false blink detection occurred 6% of the time during lateral eye movements, 10% of the time during upward movements, 47% of the time during downward movements, and 6% of the time for movements from an upward or downward gaze back to the primary gaze. Facial expressions disrupted sensor output if they caused substantial squinting or shifted the glasses. CONCLUSIONS AND RELEVANCE Our blink detection system provides a reliable, noninvasive indication of eyelid closure using an invisible light beam passing in front of the eye. Future versions will aim to mitigate detection errors by using multiple IR emitter-detector units mounted on glasses, and alternative frame designs may reduce shifting of the sensors relative to the eye during facial movements.

Project description:BackgroundIn Asian patients with severe ptosis,the use of conjoint fascia sheath (CFS) suspension or levator aponeurosis fascia complex shortening surgery can correct the ptosis. During these surgery, a significant amount of levator aponeurosis fascia shortening is performed, which often leads to serious complications such as conjunctival prolapse.This study compares two surgical approaches for correcting severe blepharoptosis:Conjoint fascial sheath (CFS) + levator aponeurosis and muller's muscle complex (LM complex) suspension and conjoint fascial sheath (CFS) + LM complex+conjunctival suspension.The postoperative efficacy and the incidence of complications such as conjunctival prolapse are investigated for both procedures.MethodsThis study retrospectively analyzed 70 patients (77eyes) with severe blepharoptosis from January 2019 to December 2021. The patients were divided into the experimental group (34 cases, 38 eyes) and the control group (36 cases, 39 eyes). The experimental group was treated with CFS+LM complex + conjunctival suspension, and the control group was treated with CFS+LM complex suspension.The curative effect of blepharoptosis, the incidence of complications such as conjunctival prolapse and patient satisfaction were compared between the two different surgical methods.ResultsThere was no significant difference in the correction effective rate between the experimental group (84.21%) and the control group (82.05%) (P > 0.05). There was no significant difference in the total incidence of complications between the experimental group (23.68%) and the control group (38.46%) (P > 0.05), but in the complication of conjunctival prolapse, the incidence of conjunctival prolapse in the experimental group was significantly lower than that in the control group. The difference was statistically significant (P < 0.05). In the survey of patient satisfaction rate, the satisfaction rate of the experimental group was significantly higher than that of the control group,which was statistically significant (P < 0.05).ConclusionsCompared to CFS+LM complex suspension surgery, the CFS+LM complex + conjunctival suspension has a definite effect in preventing postoperative conjunctival prolapse .The procedure has a high feasibility, good corrective effect, and improves patient satisfaction after surgery.

Dataset Information

Analysis of blink dynamics in patients with blepharoptosis.

Publications

Analysis of blink dynamics in patients with blepharoptosis.

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