A New Perspective on Spontaneous Blinks

Introduction: The normal blink rate for humans is between 12 and 15 blinks per minute (bpm). Screen use has been associated with decreased blink rate and increased percentage of incomplete blinks, however, little is known about the effects of videogaming on blink rate. The purpose of this study was to assess the blink rate of online livestream video game players. Methods: A total of 30 livestream video gamers across YouTube, Twitch, and Facebook Gaming were selected for this study. Video gamers were characterized by gender and whether or not they were wearing glasses. Blink rate was observed for 5 minutes and defined as a complete closure of the ocular surface. Descriptive statistics and linear regression were used to determine significance (p<0.05) between variables. All analyses were conducted using RStudio (version 1.3.1056; RStudio, Inc). Results: The study population comprised of 30 video game players (50% men). The mean (standard deviation [SD]) blink rate of the total study population was 14.79 (8.79) bpm. Compared to male gamers, female gamers had a higher mean blink rate, however this was not statistically significant (17.07 vs. 12.51, p=0.16). A total of 3 (10%) video game players wore glasses. The difference in blink rate between video game players wearing and not wearing glasses was not statistically significant (14.07 vs 14.87, p=0.88). Conclusions: The average blink rate of select livestream video game players was observed to be within the range of normal spontaneous blink rates. The observed blink rate between male and female gamers did not differ. More research in controlled environments would help to elucidate the blink rate and patterns of video game players

Validating and improving the correction of ocular artifacts in electro-encephalography

Clinical studies in patients with MSA document facial motor abnormalities, but no studies have objectively assessed blinking abnormalities in this condition. We enrolled patients diagnosed as having clinically probable MSA, 20 patients of the parkinsonian phenotype (MSA-P) and 10 patients of the cerebellar phenotype (MSA-C) and 20 healthy controls (HCs). Blinking was recorded with a three-dimensional optoelectronic motion system equipped with dedicated software for data analysis. During voluntary blinking, the interphase pause duration between the closing and opening phases lasted longer in MSA-P and in MSA-C patients than in HCs; the opening phase had increased duration and reduced peak velocity in MSA-P. During reflex blinking, the opening blink phase also lasted longer in MSA-P patients than in HCs. During spontaneous blinking, the rate and kinematics of the closing and opening blinking phases were lower in MSA-P and in MSA-C patients than in HCs. Blink reflex recovery was higher in patients than in HCs. No difference was found between MSA-P patients receiving or not receiving dopaminergic medication. Our objective assessment of upper facial movement documents abnormalities of voluntary, spontaneous, and reflex blinking in patients with MSA-P and MSA-C, reflecting cortical-basal ganglia and brainstem dysfunction.

Development and validation of a non-invasive imaging system to capture spontaneous blinking and characterise blink dynamics using a custom image analysis algorithm. A pilot study investigated the influence of illumination type on blink dynamics. Spontaneous blinking was recorded in eight subjects using a high-speed camera under two illumination conditions: white light and infrared. Custom semi-automated software assessed palpebral aperture height (PAH), blink rate, blink speed, blink completeness and blink duration. The main clinical study compared two different image analysis techniques. Spontaneous blinking was recorded in 20 subjects using a high-speed infrared camera. Blink speed and duration were determined using two techniques: manual tracking and semi-automated tracking. Agreement between the two techniques was assessed using Bland-Altman analysis. Coefficients of repeatability (COR) were calculated for the semi-automated technique. There were significant differences between white light and infrared illumination for PAH (p<0.0001), blink rate (p=0.04), closing speed (p=0.009), opening speed (p<0.0001) and blink duration (p=0.0003). The mean differences (95% limits of agreement) between the two techniques were 0.6mms-1 (-15.9 to 17.0) closing speed, 1.5mms-1 (-6.8 to 9.8) opening speed, 2.4ms (-6.8 to 11.5) closed phase duration and 5.0ms (-19.4 to 29.3) total blink duration. COR values were 10.1mms-1 closing speed, 3.7mms-1 opening speed, 6.7ms closed phase duration and 11.2ms total blink duration. This study has shown that spontaneous blinking can be characterised using a non-invasive imaging system. The semi-automated analysis provides a rapid characterisation of blink dynamics, allowing its application in large-scale trials in a number of clinical areas.

To evaluate physical methods for inducing death during the slaughter of American alligators (Alligator mississippiensis). 24 captive hatched-and-reared American alligators. Baseline electroencephalograms (EEGs) were obtained for awake and anesthetized alligators. Corneal reflex, spontaneous blinking, and EEGs were evaluated after severance of the spinal cord, severance of the spinal cord followed by pithing of the brain, application of a penetrating captive bolt, or application of a nonpenetrating captive bolt (6 alligators/group). Overall, alligators subjected to spinal cord severance alone differed from those subjected to the other techniques. Spinal cord severance alone resulted in postprocedure EEG power values greater than those in anesthetized alligators, whereas the postprocedure EEG power values were isoelectric for the other 3 techniques. Corneal reflex and spontaneous blinking were absent in all alligators immediately after application of a penetrating or nonpenetrating captive bolt. One of 6 alligators had a corneal reflex up to 1 minute after pithing, but all others within that group had immediate cessation of reflexes after pithing. Mean time to loss of spontaneous blinking and corneal reflex for alligators subjected to spinal cord severance alone was 18 minutes (range, 2 to 37 minutes) and 54 minutes (range, 34 to 99 minutes), respectively. Spinal cord severance followed by pithing of the brain and application of a penetrating or nonpenetrating captive bolt appeared to be humane and effective techniques for inducing death in American alligators, whereas spinal cord severance alone was not found to be an appropriate method.

Spontaneous Eyeblink Activity

In order to measure blinking, we developed a dynamic device consisting of a CCD camera connected to a videonystagmography machine. We developed an artificial pupil that allowed the camera to track movements of the upper eyelid. Blinking parameters were measured in eight healthy volunteers, studying spontaneous blinking (SB) and voluntary blinking (VB) responses. Closing time, opening time, closing speed, vertical amplitude, horizontal amplitude and frequency of spontaneous blinking were recorded. In SB, opening time (0.21 +/- 0.04 s) was significantly longer than closing time (0.10 +/- 0.02 s) (p < 0.0001). Mean closing speed was 87 +/- 26 m/s in SB and 168 +/- 59 m/s in VB. Mean vertical amplitude was 9.1 +/- 2.2 mm. Mean vertical amplitude was lower in SB (9.1 +/- 2.2 mm) than in VB (12.3 +/- 1.9 mm) (p < 0.001). Mean horizontal amplitude was also lower in SB (2.7 +/- 0.9 mm) than in VB (3.8 +/- 0.9 mm) (p < 0.05). Frequency of SB was 18.4 +/- 3.4 per minute. Computer-assisted video acquisition provides real-time measurement of eyeblink dynamics. On healthy volunteers, this method enables accurate measurement of opening and closing responses as well as associated horizontal movement, and enables differentiating spontaneous and voluntary blinking.

Parkinson's disease (PD) patients and the 6-hydroxydopamine (6-OHDA) lesioned rat model share blink abnormalities. In view of the evolutionarily conserved organization of blinking, characterization of blink reflex circuits in rodents may elucidate the neural mechanisms of PD reflex abnormalities. We examine the extent of this shared pattern of blink abnormalities by measuring blink reflex excitability, blink reflex plasticity, and spontaneous blinking in 6-OHDA lesioned rats. We also investigate whether 130-Hz subthalamic nucleus deep brain stimulation (STN DBS) affects blink abnormalities, as it does in PD patients. Like PD patients, 6-OHDA-lesioned rats exhibit reflex blink hyperexcitability, impaired blink plasticity, and a reduced spontaneous blink rate. At 130 Hz, but not 16 Hz, STN DBS eliminates reflex blink hyperexcitability and restores both short- and long-term blink plasticity. Replicating its lack of effect in PD patients, 130-Hz STN DBS does not reinstate a normal temporal pattern or rate to spontaneous blinking in 6-OHDA lesioned rats. These data show that the 6-OHDA lesioned rat is an ideal model system for investigating the neural bases of reflex abnormalities in PD and highlight the complexity of PD's effects on motor control, by showing that dopamine depletion does not affect all blink systems via the same neural mechanisms.

Objective To explore the feasibility and validity of the new photograph method for blepharoplasty, which was designed for collecting information of patients originally, such as eyelid abnormalities and poor appearance. Methods A lot of 1068 cases were collected and taken pictures pre- and post- operation, including six postures of looking straight forward, upward, downward, closing, squeezing and smiling, and then compared with photos taking in traditional way, only looking forward and closing. Results Compared with the traditional method, it contained more details of eyelids by six-position photography in front view, which was beneficial to the comparison of eyelid skin, muscle stretch, adhesion and dynamic changes before and after the operation. Conclusions More static and dynamic information about eyelid can be collected by simple six-position photography in front view. It is appropriate for photograph collection of blepharoplasty, with important clinical significance. Key words: Blepharoplasty; Photography; Clinic

A growing body of research suggests that spontaneous eye blinks have a cognitive role in addition to their biological functions. Blinking has been associated with cognitive effort and with processes related to the dynamic nature of incoming sensory information, such as the release of attention. However, there is limited evidence supporting the cognitive role of spontaneous blinks, specifically during reading. This study provides the first systematic investigation of blinking patterns in eye-tracking data of naturalistic silent text reading. We hypothesized that blinks would be more likely to occur (1) around punctuation marks signaling a breakpoint in the text and (2) following fixations on lower-frequency and less predictable words. To test these hypotheses, we utilized data from the large Ghent Eye Tracking Corpus (GECO), which contains eye movement data from 15 participants who read an entire novel in silence. The results indicate higher blinking proportions at punctuation marks compared to other positions in the text. Additionally, blink rates were modulated by word frequency and predictability, with higher word frequencies and predictabilities significantly reducing the probability of blinking. Extending previous research, our findings suggest substantial cognitive regulation of blinking during reading.

Teprotumumab, a novel IGF-1R antibody, has been shown to significantly reduce the signs of acute and chronic Thyroid Eye Disease (TED). Light sensitivity is a reported symptom in patients with TED. There is a lack of a prospective study that has explored the effects on light sensitivity in a large cohort of patients with acute and chronic TED following treatment with teprotumumab. Consecutive patients who were diagnosed with TED and reported light sensitivity at baseline were considered for study eligibility. All patients had measurements of Visual Light Sensitivity Questionnaire-8 (VLSQ-8), proptosis, clinical activity score (CAS), and MRD1 (distance between the upper eyelid margin and corneal reflex, mm) and MRD2 (distance between the lower eyelid margin and corneal reflex, mm) before and after treatment. Ninety patients (41 acute, 49 chronic) met the inclusion criteria. The mean (SD) age was 47.3 (14.3). Eighty-six (95.6%) patients completed all 8 infusions. There was a significant reduction in the total score and across all categories of the VLSQ-8 (p< 0.01 for all). Seventy-two (80%) patients had a clinically significant improvement (≥2 reduction) in at least one category. There was no significant difference in the total VLSQ-8 score between the acute and chronic group (p= 0.8). Teprotumumab improves light sensitivity in patients with acute and chronic TED. The results of this study highlight that the improvements in light sensitivity following treatment are not directly related to the mechanical changes in TED, suggesting another underlying mechanism ispotentially involved.

Vertical enlargement of the palpebral aperture by surgical modification of the lower eyelid: A new cosmetic option for Chinese patients

The current study evaluated the lid margin microbiome of keratinized lid margins of patients with chronic Stevens-Johnson syndrome (SJS) and compared it with healthy controls and historically reported lid margin microbiome of patients with meibomian gland dysfunction (MGD). Eyelid margin swabs of 20 asymptomatic adults (mean age = 29 ± 12years) and 10 patients with chronic SJS (mean age = 31.2 ± 14years) with lid margin keratinization were sequenced using next generation of 16S rDNA V3 to V4 variable region. Within SJS, the keratinized lid margin microbiome was compared with adjacent eyelid skin. All patients had obstructive MGD, and mean Schirmer I value was 2.8 ± 1.9 mm. The phyla were similar in two groups, whereas at the genera level, an increase in the relative abundance of Corynebacterium, Haemophilus, Azotobacter, and Afipia and a decrease of Acinetobacter was noted in SJS compared to healthy lid margins. SJS-associated microbiota displayed lesser diversity and more heterogeneity than healthy controls. The Principal Components Analysis (PCA) plot revealed wide separation in the SJS and the control groups. Correlational network analysis revealed Corynebacterium and Sphingomonas forming a major hub of negative interactions with other bacterial genera in the SJS group. Significant differences exist in the prevalent genera between keratinized lid margins and historically reported meibum microbiome of patients with MGD. In addition, the eyelid skin of patients with SJS had predominant Staphylococcus, whereas Corynebacterium and Pseudomonas were more in the keratinized lid margins compared to the eyelid skin microbiome. Lid margin microbiome is significantly altered in the keratinized lid margins of patients with SJS compared to the eyelid skin of patients with SJS, normal lid margins, and patients with MGD.

The kinematics and neurophysiological aspects of eyelid movements were examined during spontaneous, voluntary, air puff, and electrically induced blinking in healthy human subjects, using the direct magnetic search coil technique simultaneously with electromyographic recording of the orbicularis oculi muscles (OO-EMG). For OO-EMG recordings, surface electrodes were attached to the lower eyelids. To measure the vertical lid displacement, a search coil with a diameter of 3 mm was placed 1 mm from the rim on the upper eyelid on a marked position. Blink registrations were performed from the zero position and from 28 randomly chosen positions. Blinks elicited by electrical stimulation of the supraorbital nerve had shortest duration and were least variable. In contrast, spontaneous blinks had longer duration and greater variability. Blinks induced by air puff had a slightly longer duration and similar variability as electrically induced blinks. There was a correlation between the maximal down phase amplitude and the integrated OO-EMG. Blink duration and maximal down phase amplitude were affected by eye position. Eyes positioned 30 degrees above horizontal displayed the shortest down phase duration and the largest maximal down phase amplitude and velocity. At 30 degrees below horizontal, blinks had the longest total duration, the longest down phase duration, and the lowest maximal down phase amplitude and velocity. The simultaneously recorded integrated OO-EMG was largest in the 30 degrees downward position. In four subjects, the average blinking data showed a linear relation between eye position and OO-EMG, maximal down phase amplitude, and maximal downward velocity.

To evaluate corneal astigmatism with the combined high pretarsal and levator fixation gold weight implantation technique. Twenty-one eyelids of 21 patients with facial nerve palsy were prospectively enrolled. All patients underwent upper eyelid gold weight implantation using the combined high pretarsal and levator fixation technique. Keratometry and automated refraction were performed preoperatively and postoperatively. Five patients were excluded from final analysis because of incomplete keratometry data. The data were analyzed looking for statistically significant changes in lagophthalmos, automated refraction, and keratometry. A statistically significant improvement in lagophthalmos with spontaneous blinking (p = 0.0014), and gentle (p = 0.0016) and forced (p = 0.0027) closure was noted postoperatively. No significant differences were found when comparing preoperative and postoperative automated refraction readings (p = 0.89, p = 0.88), automated refraction axis (p = 0.71), keratometry readings (p = 0.40, p = 0.77), or keratometry axis (p = 0.63). Implantation of a gold weight in the upper eyelid with the combined high pretarsal and levator fixation technique does not appear to cause a significant change in corneal astigmatism. This is contrary to data for pretarsal gold weight implantation, which does induce significant with-the-rule corneal astigmatism.