Benefits and Safety of Astaxanthin in the Treatment of Mild-To-Moderate Dry Eye Disease

Objectives: To evaluate the effect of astaxanthin in the treatment of mild-to-moderate dry eye disease (DED) in middle-aged and elderly patients.Methods: 120 eyes of 60 middle-aged and elderly patients with mild-to-moderate DED were enrolled in this prospective, one-group, quasi-experimental study. Six milligram Astaxanthin tablets (Weihong Haematococcus Pluvialis Astaxanthin, Hangzhou Xinwei Low Carbon Technology R&D Co., Ltd., China) were administered orally, twice daily for 30 ± 2 days. History of eye diseases, treatment, systemic disease, and medication before the test were recorded. In addition, the ocular surface disease index (OSDI) questionnaire, non-invasive tear break-up time (NIBUT), fluorescein break-up time (FBUT), corneal fluorescein staining (CFS) score, eyelid margin signs, meibomian gland (MG) expressibility, meibum quality, meibomian gland dropout (MGDR), Schirmer I test (SIt), tear meniscus height (TMH), bulbar conjunctiva congestion degree, blink frequency, incomplete blink rate, and thickness of tear film lipid layer were collected before treatment, 2 weeks after the initiation of treatment, and at the end of treatment. Visual acuity (VA), intraocular pressure (IOP), anterior segment, fundus, discomfort symptoms and other adverse reactions were also monitored throughout the study to assess the safety.Results: OSDI score, NIBUT, BUT, CFS score, eyelid margin signs, MG expressibility, meibum quality, and blink frequency improved significantly to varying degrees after treatment compared with those before the treatment (P < 0.05), while TMH, SIt, conjunctival congestion, the thickness of tear film lipid layer, MGDR, incomplete blink rate, VA and IOP did not differ (P > 0.05).Conclusions: Oral administration of astaxanthin improves the symptoms and signs of middle-aged and elderly patients with mild-to-moderate DED.

Detecting Soldiers’ Fatigue Using Eye-Tracking Glasses: Practical Field Applications and Research Opportunities

ABSTRACT Introduction Objectively determining soldiers’ fatigue levels could help prevent injuries or accidents resulting from inattention or decreased alertness. Eye-tracking technologies, such as optical eye tracking (OET) and electrooculography (EOG), are often used to monitor fatigue. Eyeblinks—especially blink frequency and blink duration—are known as easily observable and valid biomarkers of fatigue. Currently, various eye trackers (i.e., eye-tracking glasses) are available on the market using either OET or EOG technologies. These wearable eye trackers offer several advantages, including unobtrusive functionality, practicality, and low costs. However, several challenges and limitations must be considered when implementing these technologies in the field to monitor fatigue levels. This review investigates the feasibility of eye tracking in the field focusing on the practical applications in military operational environments. Materials and Method This paper summarizes the existing literature about eyeblink dynamics and available wearable eye-tracking technologies, exposing challenges and limitations, as well as discussing practical recommendations on how to improve the feasibility of eye tracking in the field. Results So far, no eye-tracking glasses can be recommended for use in a demanding work environment. First, eyeblink dynamics are influenced by multiple factors; therefore, environments, situations, and individual behavior must be taken into account. Second, the glasses’ placement, sunlight, facial or body movements, vibrations, and sweat can drastically decrease measurement accuracy. The placement of the eye cameras for the OET and the placement of the electrodes for the EOG must be chosen consciously, the sampling rate must be minimal 200 Hz, and software and hardware must be robust to resist any factors influencing eye tracking. Conclusion Monitoring physiological and psychological readiness of soldiers, as well as other civil professionals that face higher risks when their attention is impaired or reduced, is necessary. However, improvements to eye-tracking devices’ hardware, calibration method, sampling rate, and algorithm are needed in order to accurately monitor fatigue levels in the field.

Mental fatigue prediction during eye-typing

Mental fatigue is a common problem associated with neurological disorders. Until now, there has not been a method to assess mental fatigue on a continuous scale. Camera-based eye-typing is commonly used for communication by people with severe neurological disorders. We designed a working memory-based eye-typing experiment with 18 healthy participants, and obtained eye-tracking and typing performance data in addition to their subjective scores on perceived effort for every sentence typed and mental fatigue, to create a model of mental fatigue for eye-typing. The features of the model were the eye-based blink frequency, eye height and baseline-related pupil diameter. We predicted subjective ratings of mental fatigue on a six-point Likert scale, using random forest regression, with 22% lower mean absolute error than using simulations. When additionally including task difficulty (i.e. the difficulty of the sentences typed) as a feature, the variance explained by the model increased by 9%. This indicates that task difficulty plays an important role in modelling mental fatigue. The results demonstrate the feasibility of objective and non-intrusive measurement of fatigue on a continuous scale.

Eyeblink Detection in the Field: A Proof of Concept Study of Two Mobile Optical Eye-Trackers

ABSTRACT Introduction High physical and cognitive strain, high pressure, and sleep deficit are part of daily life for military professionals and civilians working in physiologically demanding environments. As a result, cognitive and physical capacities decline and the risk of illness, injury, or accidents increases. Such unfortunate outcomes could be prevented by tracking real-time physiological information, revealing individuals’ objective fatigue levels. Oculometrics, and especially eyeblinks, have been shown to be promising biomarkers that reflect fatigue development. Head-mounted optical eye-trackers are a common method to monitor these oculometrics. However, studies measuring eyeblink detection in real-life settings have been lacking in the literature. Therefore, this study aims to validate two current mobile optical eye-trackers in an unrestrained military training environment. Materials and Method Three male participants (age 20.0 ± 1.0) of the Swiss Armed Forces participated in this study by wearing three optical eye-trackers, two VPS16s (Viewpointsystem GmbH, Vienna, Austria) and one Pupil Core (Pupil Labs GmbH, Berlin, Germany), during four military training events: Healthcare education, orienteering, shooting, and military marching. Software outputs were analyzed against a visual inspection (VI) of the video recordings of participants’ eyes via the respective software. Absolute and relative blink numbers were provided. Each blink detected by the software was classified as a “true blink” (TB) when it occurred in the software output and the VI at the same time, as a “false blink” (FB) when it occurred in the software but not in the VI, and as a “missed blink” (MB) when the software failed to detect a blink that occurred in the VI. The FBs were further examined for causes of the incorrect recordings, and they were divided into four categories: “sunlight,” “movements,” “lost pupil,” and “double-counted”. Blink frequency (i.e., blinks per minute) was also analyzed. Results Overall, 49.3% and 72.5% of registered eyeblinks were classified as TBs for the VPS16 and Pupil Core, respectively. The VPS16 recorded 50.7% of FBs and accounted for 8.5% of MBs, while the Pupil Core recorded 27.5% of FBs and accounted for 55.5% of MBs. The majority of FBs—45.5% and 73.9% for the VPS16 and Pupil Core, respectively—were erroneously recorded due to participants’ eye movements while looking up, down, or to one side. For blink frequency analysis, systematic biases (±limits of agreement) stood at 23.3 (±43.5) and −4.87 (±14.1) blinks per minute for the VPS16 and Pupil Core, respectively. Significant differences in systematic bias between devices and the respective VIs were found for nearly all activities (P < .05). Conclusion An objective physiological monitoring of fatigue is necessary for soldiers as well as civil professionals who are exposed to higher risks when their cognitive or physical capacities weaken. However, optical eye-trackers’ accuracy has not been specified under field conditions—especially not in monitoring fatigue. The significant overestimation and underestimation of the VPS16 and Pupil Core, respectively, demonstrate the general difficulty of blink detection in the field.

Facial expressions of emotional stress in horses

Horses have the ability to generate a remarkable repertoire of facial expressions, some which have been linked to certain emotional states, for example pain. Studies suggest that facial expressions may be a more ‘honest’ expression of emotional state in horses than behavioral or physiological parameters. This study sought to describe the facial expressions during stress of healthy horses free of pain, using a standardized method of recording facial expressions in video. Stress was induced in 28 horses by subjecting them to road transport and 10 of these horses were also subjected to social isolation. The horses served as their own control. A body-mounted, remote controlled heart rate monitor provided continuous heart rate measurements during the interventions. The horses’ facial expressions were video-recorded during the interventions. Frequency and duration of each facial expression were then determined, according to the Equine Facial Action Coding System. Heart rate increased during the stressful interventions (p=0.01), confirming that the interventions were stressful. Using both the human investigation- and the co-occurrence methods, the following facial traits could be observed during stress: eye white increase (p<0.001), nostril dilator (p<0.001), upper eyelid raiser (p<0.001), inner brow raiser (p=0.042), tongue show (p<0.001) along with an increase in ‘ear flicker’ (p<0.001) and blink frequency (p<0.001). The facial actions were successfully used to train a machine-learning classifier to discriminate between stressed and calm horses, with an accuracy of 74.2 %. Most of the facial features identified correspond well with previous research on the subject, for example flared nostrils, repetitive mouth behaviors, increased eye white, tongue show and ear movements. Some features selected as indicative of emotional pain-free stress are used in face-based pain assessment tools, such as dilated nostrils, eye white increase or inner brow raiser. The relation between facial expressions of stress and pain should therefore further be studied.

Evaluation of Subjective and Objective Levels of Drowsiness, it’s Rating and its Relation with Facial Dynamics

Objective: To determine the subjective and observed levels of lethargy and changes in facial dynamics. Materials and Methods: This study was conducted at Department of community medicine, Services Institute of Medical Sciences Lahore for one-year duration from January 2017 to December 2018. The changes in facial dynamics, such as changes in eyes, lips and eyebrows, were tested in KKS (Karolinska Sleepiness Scale) in twenty-five drivers. And ORD (drowsiness observer rating). Repeated ANOVA measurements and repeated MANOVA measurements were used to analyze the data. In addition, a neural network and Viola-Jones were used to detect facial features. PERCLOS (percentage of eye closure), blink frequency and blink time were examined to see eye parameters. The size of the open mouth during sleep was examined for oral parameters. When examining the eyebrows, the number 50 indicates that the eyebrow is in the normal position. For eyebrows above the normal position, a range of 50 to 55 was specified; In addition, 45-50 was found to be a defined range for normal eyebrows. Results: Descriptive statistics of dynamic changes in the mouth and eyes showed increased drowsiness while driving, as well as changes in the eyes and mouth. However, statistical findings made while driving showed that dynamic eyebrow changes had a clear expression with a continuous trend. Similar studies on data obtained from CSR and ORD showed that both parameters increased at the same time and lethargy level. There was also a significant relationship between facial expressions and lethargy. Conclusion: This study will be an effective and efficient tool for alerting and detecting sleep in a timely and accurate manner.

Social signaling via bioluminescent blinks drives schooling behavior in the flashlight fish Anomalops katoptron

The bioluminescent flashlight fish Anomalops katoptron live in schools of several hundred specimens. To understand how flashlight fish, integrate bioluminescent signaling into their schooling behavior, we analyzed movement profiles and blink frequencies. Isolated specimen of A. katoptron show a high motivation to align with fixed or moving artificial light organs. Depending on presented frequencies A. katoptron responds with a reduction in swimming speed and its own blink frequency. Higher presented blink frequencies reduce the nearest neighbor distance. In the natural environment A. katoptron is changing its blink frequencies and nearest neighbor distance in a context specific manner. Blink frequencies are increased from day to night and during avoidance behavior, while nearest neighbor distance is decreased with increasing blink frequencies. A. katoptron changes its blink frequencies by modifying light organ occlusion. Our results suggest that visually transmitted information via specific blink patterns determine intraspecific communication and group cohesion in schooling A. katoptron.

36 Too Scared to Blink: Pseudoparkinsonism due to Nyctophobia

IntroductionA hallmark of Parkinson’s disease is facial akinesia with decrease in blink frequency (Karson, 1984). A markedly decreased blink frequency from nyctophobia, a fear of the dark, has not heretofore been reported.MethodCase Study: A 26-year-old right handed male presented with a 20-year history of phantasmagoria. Visual hallucinations of strangers appeared several to a hundred times a day, seconds to minutes in duration. These morbid images were horrific, of dead people or ghosts, suddenly appearing in his visual space, actively attacking real people. Examples included a little girl, decapitated, cradling her head in her arm or Freddy Krueger like apparitions, shooting, stabbing, strangling or maiming actual people who were within the patient’s visual field. He was able to differentiate between the hallucinations and real people, either from the context (a non hallucination would not be murdering someone else), or he would wait for the hallucinations to vanish, allowing him to then interact with the person who is actually there. The images were so disturbing to him that he fled his home state to run away from the hallucinations, but to his chagrin, they persisted. There were diurnal variations to his hallucinations, which were more frequent at night, or when he closed his eyes, and the fear of these has induced nyctophobia. In order to avoid these, he attempted to curtail closing his eyes or blinking. He had been treated with 9 different psychotropic medications, which had no effect on his hallucinations. Phenytoin was begun, and once therapeutic levels were achieved, all of his hallucinations resolved, as did his nyctophobia, with return to normal blink frequency.ResultsPhysical examination: Bilateral palmar erythema. Facial expression with decreased blink frequency, approximately 1/per minute, but not otherwise hypomimetic. Neurological examination: Cranial Nerve (CN) Examination: CN III, IV and VI: bilateral ptosis. Motor Examination: Normal tone without cogwheel rigidity. No bradykinesia. Drift Testing: Right upward-outward drift, right cerebellar spooning, and Abductor Digiti Minimi sign. Gait: Normal without instability or retropulsion. Reflexes: 1+ throughout. Hoffman Reflex: positive bilaterally. Other: Magnetic Resonance Imaging of brain with/without infusion: Normal. Five-day Electroencephalogram: Temporal Lobe Status Epilepticus with bilateral foci.DiscussionIn this individual, the sheer terror of phantasmagoria with his eyes closed, forced him to maintain them in the open position as long as possible, reducing his blink frequency to once a minute or less. The return to a normal rate of blink frequency with treatment using phenytoin, with resolution of his horrific hallucinations, further validates this as the origin for his infrequent blinking. In those with low nictation, without other manifestations of Parkinson’s disease, query as to volitional inhibition of blink frequency and nyctophobia is warranted.