ABSTRACT
Sleep spindle generation classically relies on an interplay between the thalamic reticular nucleus (TRN), thalamo-cortical (TC) relay cells and cortico-thalamic (CT) feedback during non-rapid eye movement (NREM) sleep. Spindles are hypothesized to stabilize sleep, gate sensory processing and consolidate memory. However, the contribution of non-sensory thalamic nuclei in spindle generation and the role of spindles in sleep-state regulation remain unclear. Using multisite thalamic and cortical LFP/unit recordings in freely behaving mice, we show that spike-field coupling within centromedial and anterodorsal (AD) thalamic nuclei is as strong as for TRN during detected spindles. We found that spindle rate significantly increases before the onset of rapid eye movement (REM) sleep, but not wakefulness. The latter observation is consistent with our finding that enhancing spontaneous activity of TRN cells or TRN-AD projections using optogenetics increase spindle rate and transitions to REM sleep. Together, our results extend the classical TRN-TC-CT spindle pathway to include non-sensory thalamic nuclei and implicate spindles in the onset of REM sleep.
Subject(s)
Ocular Physiological Phenomena , Sleep, REM , Thalamic Nuclei/physiology , Animals , Electroencephalography , Eye/chemistry , Female , Male , Memory , Mice, Inbred C57BL , Optogenetics , Thalamic Nuclei/chemistry , Thalamus/chemistry , Thalamus/physiology , WakefulnessABSTRACT
Perfluorobutanesulfonate (PFBS), an aquatic pollutant of emerging concern, is found to disturb gut microbiota, retinoid metabolism and visual signaling in teleosts, while probiotic supplementation can shape gut microbial community to improve retinoid absorption. However, it remains unknown whether probiotic bacteria can modulate the toxicities of PFBS on retinoid metabolism and visual physiology. In the present study, adult zebrafish were exposed for 28 days to 0, 10 and 100 µg/L PFBS, with or without dietary administration of probiotic Lactobacillus rhamnosus. Interaction between PFBS and probiotic was examined regarding retinoid dynamics (intestine, liver and eye) and visual stimuli transmission. PFBS single exposures remarkably inhibited the absorption of retinyl ester in female intestines, which were, however, restored by probiotic to normal status. Although coexposure scenarios markedly increased the hepatic storage of retinyl ester in females, mobilization of retinol was reduced in livers by single or combined exposures regardless of sex. In the eyes, transport and catalytic conversion of retinol to retinal and retinoic acid were interrupted by PFBS alone, which were efficiently antagonized by probiotic presumably through an indirect action. In response to the availability of retinal chromophore, transcriptions of opsins and arrestin genes were altered adaptively to control visual perception and termination. Neurotransmission across retina circuitry was changed accordingly, centering on epinephrine and norepinephrine. In summary, the present study found the efficient modulation of probiotic on retinoid metabolic disorders of PFBS pollution, which subsequently impacted visual signaling. A future work is warranted to provide mechanistic clues in retinoid interaction.
Subject(s)
Fluorocarbons/toxicity , Ocular Physiological Phenomena/drug effects , Probiotics/pharmacology , Retinoids/metabolism , Sulfonic Acids/toxicity , Water Pollutants, Chemical/toxicity , Zebrafish/metabolism , Animals , Eye/drug effects , Eye/metabolism , Female , Lipid Metabolism/drug effects , Opsins/genetics , Signal Transduction , Transcription, Genetic/drug effectsABSTRACT
The goal of the study was to assess whether tonic immobility (TI)-induced stress reactions in laying hens can be reduced by probiotic supplementation and if the changes in body surface temperature, as a stress indicator, are genetically dependent and can be detected using infrared thermography (IRT). Seventy-one white and 70 brown hens were used. Hens were randomly assigned to three treatments at 1-day-old: beak trimmed and fed a regular diet; non-beak trimmed and fed a regular diet; and non-beak trimmed and fed a diet supplemented with probiotics, Bacillus subtilis. At 40 weeks of age, hens were tested for TI reactions. Eye and face temperatures were measured with IRT immediately before and after TI testing. Results revealed that the probiotic supplementation did not affect hens' stress responses to TI testing; the left and right eye temperatures increased by 0.26s°C and 0.15°C, respectively, while right face temperature tended to increase following TI testing. However, the right eye (32.60°C for white, and 32.35°C for brown) and face (39.51°C for white, and 39.36°C for brown) temperatures differed significantly among genetic lines. There was a positive correlation between TI duration and the changes of the left and right eye temperatures after TI testing in white hens. Based on these results, hens experienced TI-induced surface temperature changes that were detectable using IRT. White hens experienced greater stress reactions in response to TI than brown hens. However, supplementation with Bacillus subtilis did not attenuate hens' reaction to TI testing.
Subject(s)
Bacillus subtilis/physiology , Probiotics/administration & dosage , Stress, Physiological , Thermography/methods , Animals , Body Temperature , Chickens , Dietary Supplements , Infrared Rays , Ocular Physiological PhenomenaABSTRACT
Polycyclic aromatic hydrocarbons (PAHs) present in crude oil have been shown to cause the dysregulation of genes important in eye development and function, as well as morphological abnormalities of the eye. However, it is not currently understood how these changes in gene expression are manifested as deficits in visual function. Embryonic red drum (Sciaenops ocellatus) and sheepshead minnow (Cyprinodon variegatus) were exposed to water accommodated fractions (WAFs) of weathered crude oil and assessed for visual function using an optomotor response assay in early life-stage larvae, with subsequent samples taken for histological analysis of the eyes. Larvae of both species exposed to increasing concentrations of oil exhibited a reduced optomotor response. The mean diameters of retinal layers, which play an important role in visual function and image processing, were significantly reduced in oil-exposed sheepshead larvae, though not in red drum larvae. The present study provides evidence that weathered crude oil has a significant effect on visual function in early life-stage fishes.
Subject(s)
Eye/drug effects , Killifishes/growth & development , Perciformes/growth & development , Petroleum/toxicity , Water Pollutants, Chemical/toxicity , Animals , Eye/anatomy & histology , Eye/growth & development , Killifishes/anatomy & histology , Killifishes/embryology , Killifishes/physiology , Larva/anatomy & histology , Larva/drug effects , Ocular Physiological Phenomena/drug effects , Perciformes/anatomy & histology , Perciformes/embryology , Perciformes/physiologyABSTRACT
Chinese eye exercises have been implemented in China as an intervention for controlling children's myopia for over 50 years. This nested case-control study investigated Chinese eye exercises and their association with myopia development in junior middle school children. Outcome measures were the onset and progression of myopia over a two-year period. Cases were defined as 1. Myopia onset (cycloplegic spherical equivalent ≤ -0.5 diopter in non-myopic children). 2. Myopia progression (myopia shift of ≥1.0 diopter in those who were myopic at baseline). Two independent investigators assessed the quality of Chinese eye exercises performance at the end of the follow-up period. Of 260 children at baseline (mean age was 12.7 ± 0.5 years), 201 were eligible for this study. There was no association between eye exercises and the risk of myopia-onset (OR = 0.73, 95%CI: 0.24-2.21), nor myopia progression (OR = 0.79, 95%CI: 0.41-1.53). The group who performed high quality exercises had a slightly lower myopia progression of 0.15 D than the children who did not perform the exercise over a period of 2 years. However, the limited sample size, low dosage and performance quality of Chinese eye exercises in children did not result in statistical significance and require further studies.
Subject(s)
Exercise Therapy/methods , Myopia/prevention & control , Acupuncture Points , Adolescent , Case-Control Studies , Child , China/epidemiology , Disease Progression , Female , Follow-Up Studies , Humans , Male , Massage/methods , Medicine, Chinese Traditional/methods , Myopia/epidemiology , Myopia/etiology , Ocular Physiological Phenomena , Refraction, Ocular , Risk FactorsABSTRACT
BACKGROUND: Ocular blood flow alterations and blindness are uncommon and less-known adverse effects of nasal local anesthetic infiltrations. Our aim was to investigate ocular blood flow alterations during radiofrequency (RF) tissue reduction of inferior turbinates with the patient under local anesthesia by using a noninvasive method with optical coherence tomography. METHODS: A total of 120 patients with inferior turbinate hypertrophy were prospectively randomized into two groups. In group 1, a total of 61 patients underwent RF tissue reduction while under local anesthesia with epinephrine. In group 2, a total of 59 patients underwent RF tissue reduction of inferior turbinates while under local anesthesia without epinephrine. Optical coherence tomography measurements were performed before surgery and at 5, 15, 30, 45, and 60 minutes after local anesthetic infiltration. RESULTS: Choroid thickness measurements decreased gradually after local anesthetic infiltration until 30 minutes and increased to the same plane with the baseline at 60 minutes in group 1 (p < 0.05). In group 2, the choroid thickness measurement was significantly decreased after local anesthetic infiltration at 15 and 45 minutes (p < 0.05). When the choroid thickness measurements were compared between the groups, in group 1 blood flow was significantly lower than in group 2 at 30 minutes (p < 0.05). CONCLUSION: We observed a statistically significant reduction in choroid circulation after local anesthetic with epinephrine infiltration into inferior turbinates. Otolaryngologists should be careful after local anesthetic infiltration, and monitor the vision. Further studies with larger series would be needed to discuss safety of local anesthetics.
Subject(s)
Analgesics/therapeutic use , Choroid/anatomy & histology , Epinephrine/therapeutic use , Eye/pathology , Nasal Obstruction/surgery , Regional Blood Flow , Turbinates/pathology , Adolescent , Adult , Anesthesia, Local , Female , Humans , Hypertrophy , Male , Ocular Physiological Phenomena , Prospective Studies , Pulsed Radiofrequency Treatment , Tomography, Optical Coherence/methods , Treatment Outcome , Turbinates/surgery , Young AdultABSTRACT
Generally, eye closure (EC) and eye opening (EO)-based alpha blocking has widely recognized advantages, such as being easy to use, requiring little user training, while motor imagery (MI) is difficult for some users to have concrete feelings. This study presents a hybrid brain-computer interface (BCI) combining MI and EC strategies - such an approach aims to overcome some disadvantages of MI-based BCI, improve the performance and universality of the BCI. The EC/EO is employed to control the machine to switch in different states including forward, stop, changing direction motions, while the MI is used to control the machine to turn left or right for 90° by imagining the hands grasp motions when the system is switched into "changing direction" state. Additionally, a wearable two-channel EEG device is utilized in order to increase the efficiency of EEG processing and improving the practical utility. Results show that proposed hybrid system can generate four control commands with the average accuracy of 87.72%, which is higher than only using MI. Besides, it is possible to reach the same good accuracy using two-channel EEG as with usual multi-channel EEG.
Subject(s)
Brain-Computer Interfaces , Ocular Physiological Phenomena , Adult , Algorithms , Electroencephalography , Evoked Potentials/physiology , Humans , Imagery, Psychotherapy , Male , Signal Processing, Computer-Assisted , Wireless Technology , Young AdultABSTRACT
This study presents first evidence that reliable EEG data can be recorded with a new cEEGrid electrode array, which consists of ten electrodes printed on flexible sheet and arranged in a c-shape to fit around the ear. Ten participants wore two cEEGrid systems for at least seven hours. Using a smartphone for stimulus delivery and signal acquisition, resting EEG and auditory oddball data were collected in the morning and in the afternoon six to seven hours apart. Analysis of resting EEG data confirmed well-known spectral differences between eyes open and eyes closed conditions. The ERP results confirmed the predicted condition effects with significantly larger P300 amplitudes for target compared to standard tones, and a high test-retest reliability of the P300 amplitude (r > = .74). Moreover, a linear classifier trained on data from the morning session revealed similar performance in classification accuracy for the morning and the afternoon sessions (both > 70%). These findings demonstrate the feasibility of concealed and comfortable brain activity acquisition over many hours.
Subject(s)
Electroencephalography , Ocular Physiological Phenomena , Smartphone , Acoustic Stimulation , Adult , Brain/physiology , Electrodes , Evoked Potentials/physiology , Female , Humans , Male , Middle Aged , Young AdultABSTRACT
BACKGROUND: Oxidative stress (OS) and its biomarkers are the biochemical end point of the imbalance between reactive oxygen species (ROS) production and the ability of the antioxidant (AOX) biological systems to fight against oxidative injury. OBJECTIVE: We reviewed the role of OS and its downstream signaling in aging eyes. METHODS: A search of the literature and current knowledge on the physiological and pathological mechanisms of OS were revisited in relation to the eyes and the aging process. Most prevalent ocular diseases have been analyzed herein in relation to OS and nutraceutic supplements, such as dry-eye disorders, glaucoma, age-related macular degeneration, and diabetic retinopathy. RESULTS: Clinical, biochemical, and molecular data from anterior and posterior eye segment diseases point to OS as the common pathogenic mechanism in the majority of these ocular disorders, many of which are pathologies causing visual impairment, blindness, and subsequent loss of life quality. Studies with nutraceutic supplements in aging eye-related pathologies have also been reviewed. CONCLUSION: OS, nutritional status, and nutraceutic supplements have to be considered within the standards of care of older ophthalmologic patients. OS biomarkers and surrogate end points may help in managing the aging population with ocular diseases.
Subject(s)
Aging/metabolism , Eye/metabolism , Oxidative Stress/physiology , Aged , Aging/physiology , Dietary Supplements , Dry Eye Syndromes/metabolism , Dry Eye Syndromes/physiopathology , Glaucoma/metabolism , Glaucoma/physiopathology , Humans , Ocular Physiological Phenomena , Retinal Diseases/metabolism , Retinal Diseases/physiopathologyABSTRACT
BACKGROUND: Air-conducted (ACS) cervical VEMP (cVEMP) reflect both saccular and inferior vestibular nerve function. Ocular VEMP (oVEMP) to air and bone-conducted vibration (BCV) are critically discussed, whether they reflect predominantly utricular and superior vestibular nerve function. The video head impulse test (vHIT) accurately detects changes in the high frequency range (5-7 Hz) of the vestibular ocular reflex (VOR) in all 3 planes and can be used to assess semicircular canals (SCC) impairment. OBJECTIVES: To evaluate oVEMP and cVEMP in response to 500 Hz ACS stimulation and to compare these with vHIT results in acute unilateral vestibular neuritis (VN) to classify the probable involvement of SCC and otolith organs. MATERIALS AND METHODS: Patients with VN were studied. ACS oVEMP and ACS cVEMP (100 dB nHL 500 Hz tone burst stimulation) were recorded. The vHIT for the 3 SCC were performed simultaneously. RESULTS: ACS oVEMP and ACS cVEMP in combination with vHIT allows the differentiation of 4 types of VN: entire VN (EVN), superior VN (SVN), inferior VN (IVN), and ampullary VN (AVN). Lesions of EVN, SVN, and IVN may be either complete or partial. CONCLUSION: ACS oVEMP and ACS cVEMP to 500 Hz stimulation together with the vHIT allows a better differentiation of receptor involvement in VN. Results suggest a different origin of AC oVEMP and AC cVEMP to 500 Hz in complete SVN and IVN. Partial SVN and IVN may indicate a role of saccular fibers in oVEMP.
Subject(s)
Head Impulse Test/methods , Neurologic Examination/methods , Vestibular Evoked Myogenic Potentials/physiology , Vestibular Neuronitis/diagnosis , Acoustic Stimulation , Acute Disease , Adult , Aged, 80 and over , Air , Dizziness/etiology , Electroencephalography , Female , Functional Laterality/physiology , Humans , Male , Middle Aged , Ocular Physiological Phenomena , Physical Stimulation , Postural Balance/physiology , Vestibular Neuronitis/physiopathology , Young AdultABSTRACT
Tics in Tourette Syndrome (TS) are often preceded by 'premonitory urges': annoying feelings or bodily sensations. We hypothesized that, by reducing annoyance of premonitory urges, tic behaviour may be reinforced. In a 2X2 experimental design in healthy participants, we studied the effects of premonitory urges (operationalized as air puffs on the eye) and tic behaviour (deliberate eye blinking after a puff or a sound) on changes in subjective evaluation of air puffs, and EMG responses on the m. orbicularis oculi. The experimental group with air puffs+ blinking experienced a decrease in subjective annoyance of the air puff, but habituation of the EMG response was blocked and length of EMG response increased. In the control groups (air puffs without instruction to blink, no air puffs), these effects were absent. When extrapolating to the situation in TS patients, these findings suggest that performance of tics is reinforced by reducing the subjective annoyance of premonitory urges, while simultaneously preventing habituation or even inducing sensitisation of the physiological motor response.
Subject(s)
Blinking/physiology , Electromyography/methods , Facial Muscles/physiology , Tics/physiopathology , Tics/psychology , Acoustic Stimulation/methods , Adult , Female , Humans , Male , Neuropsychological Tests , Ocular Physiological Phenomena , Reinforcement, Psychology , Tourette Syndrome/physiopathology , Young AdultABSTRACT
OBJECTIVE: To measure the frequency dynamics of cervical and ocular vestibular evoked myogenic potentials in healthy subjects and patients with Ménière's disease. STUDY DESIGN: A prospective cohort study. SETTING: A university teaching hospital. SUBJECTS: Eight healthy volunteers (16 ears) and 12 adult patients with unilateral Ménière's disease (8 with definite disease and 4 with probable disease) by American Academy of Otolaryngology - Head and Neck Surgery diagnostic criteria. INTERVENTIONS: Cervical and ocular vestibular evoked myogenic potentials generated by tone bursts at 250, 500, 750, 1,000, 1,500, 2,000, 3,000, and 4,000 Hz were measured in both groups. MAIN OUTCOME MEASURES: The frequency sensitivity of both the cervical and ocular vestibular evoked myogenic potentials, as evaluated by p13-n23 and n10 amplitudes in healthy ears and in ears affected and not affected by Ménière's disease. RESULTS: Cervical and ocular vestibular evoked myogenic potentials were present in all ears tested. In the healthy volunteers, the acoustic stimulus frequency at which the response amplitudes were largest was 500 Hz. This shifted to higher frequencies in patients with definite Ménière's disease for both measurements, with the effect being more pronounced for ocular vestibular evoked myogenic potentials. The shift was less marked in the probable Ménière's group and was absent in the unaffected ears of the Ménière's patients. CONCLUSION: Ménière's ears display alterations in cervical and ocular vestibular evoked myogenic potentials tuning responses with changes in the latter being more prominent. These findings indicate that the disease process affects both the otolith organs but may have an enhanced effect on the utricle. We propose that this more dominant affect may relate to the anatomical configuration of the utricle.
Subject(s)
Cervical Vertebrae/physiopathology , Meniere Disease/physiopathology , Ocular Physiological Phenomena , Vestibular Evoked Myogenic Potentials/physiology , Acoustic Stimulation , Adult , Aged , Calibration , Cohort Studies , Female , Humans , Male , Middle Aged , Prospective Studies , Reference ValuesABSTRACT
In the present study, we tested the hypothesis that compared with non-athletes, elite athletes are characterized by a reduction of reactivity of electroencephalographic (EEG) alpha rhythms (about 8-12 Hz) to eyes opening in the condition of resting state, as a possible index of spatially selective cortical activation (i.e. "neural efficiency"). EEG data (56 channels; Eb-Neuro©) were recorded in 18 elite karate athletes and 28 non-athletes during resting state eyes-closed and eyes-open conditions. The EEG data were spatially enhanced by surface Laplacian estimation. Cortical activity was indexed by task-related power decrease (TRPD), namely the alpha power during the eyes-open referenced to the eyes-closed resting condition. Low-frequency alpha TRPD (about 8-10 Hz) was lower in the elite karate athletes than in the non-athletes in frontal (p<0.00002), central (p<0.008) and right occipital (p<0.02) areas. Similarly, high-frequency alpha TRPD (about 10-12 Hz) was lower in the elite karate athletes than in the non-athletes in frontal (p<0.00009) and central (p<0.01) areas. These results suggest that athletes' brain is characterized by reduced cortical reactivity to eyes opening in the condition of resting state, in line with the "neural efficiency" hypothesis. The present study motivates future research evaluating the extent to which this general functional brain feature is related to heritable trait or intensive visuo-motor training of elite athletes.
Subject(s)
Alpha Rhythm/physiology , Electroencephalography , Ocular Physiological Phenomena , Sports/psychology , Adolescent , Adult , Algorithms , Brain Mapping , Data Interpretation, Statistical , Female , Humans , Male , Martial Arts/physiology , Martial Arts/psychology , Photic Stimulation , Psychomotor Performance/physiology , Young AdultABSTRACT
PURPOSE: To determine whether corneal biomechanical properties and intraocular pressure (IOP) are affected by eye rubbing and breath holding. METHODS: Corneal hysteresis, corneal resistance factor, corneal compensated IOP (IOPcc), and Goldmann equivalent IOP (IOPg) were measured on both eyes of 40 subjects. Measurements were taken at baseline before eye rubbing (ER(0)) and before breath holding (BH(0)), immediately after 2 episodes of eye rubbing (ER(1) and ER(2)), and during 2 episodes of breath holding (BH(1) and BH(2)). RESULTS: Corneal hysteresis, corneal resistance factor, and IOPg were significantly lower after ER(1) compared with ER(0) and were significantly lower after ER(2) compared with ER(1). In contrast, IOPcc did not decrease significantly. There were no significant differences among BH(0), BH(1), and BH(2) in any of the 4 outcomes. CONCLUSIONS: Eye rubbing should be avoided before measurements of corneal biomechanical properties and IOPg. In contrast, breath holding during measurements is not likely to cause a significant change in IOPg and IOPcc or corneal biomechanical properties.
Subject(s)
Biomechanical Phenomena/physiology , Cornea/physiology , Intraocular Pressure/physiology , Massage , Ocular Physiological Phenomena , Respiratory Mechanics/physiology , Adolescent , Adult , Female , Humans , Male , Middle Aged , Tonometry, Ocular , Young AdultABSTRACT
Piloerection is known as an indicator of strong emotional experiences. However, little is known about the physiological and emotional specificity of this psychophysiological response. In the presented study, piloerection was elicited by audio stimuli taken from music and film episodes. The physiological response accompanying the incidence of piloerection was recorded with respect to electrodermal, cardiovascular and respiratory measures and compared to a matched control condition. The employment of an optical recording system allowed for a direct and objective assessment of visible piloerection. The occurrence of piloerection was primarily accompanied by an increase of phasic electrodermal activity and increased respiration depth as compared to a matched control condition. This physiological response pattern is discussed in the context of dominant theories of human piloerection. Consideration of all available evidence suggests that emotional piloerection represents a valuable indicator of the state of being moved or touched.
Subject(s)
Emotions/physiology , Ocular Physiological Phenomena , Piloerection/physiology , Statistics as Topic , Acoustic Stimulation , Adolescent , Adult , Chi-Square Distribution , Female , Galvanic Skin Response/physiology , Heart Rate/physiology , Humans , Male , Music , Psychophysiology , Reaction Time/physiology , Respiration , Time Factors , Young AdultABSTRACT
OBJECTIVE: To establish reference values for the Schirmer tear test I (STT I), the phenol red thread tear test (PRTT), the intraocular pressure (IOP) with rebound tonometry, to determine the corneal sensitivity for healthy chinchillas, and to describe clinical aspects of normal chinchilla eyes. ANIMALS: One hundred and twenty-two eyes of 61 healthy pet chinchillas of different age and gender were investigated. PROCEDURES: A full ophthalmic exam including slit lamp biomicroscopy, ophthalmoscopy, measurement of STT I, PRTT, determination of the corneal touch threshold (CTT), and the measurement of the IOP (TonoVet) was performed. The normal appearance of the lid, the iris, the lens, the fundus, and the optic nerve disc was evaluated. Results The results of the STT I were very low and not reliable, and the measurement was discontinued. The median value of PRTT was 14.0 mm wetting/15 s (mean 14.6 ± 3.5 mm wetting/15 s). The median CTT was 32.5 mm (mean 31.2 ± 7.0 mm) respectively 1.2 g/mm(2) (mean 1.5 ± 0.9 g/mm(2)). The median IOP was 3.0 mmHg (mean 2.9 ± 1.8 mmHg). The predominating iris color was brown. The fundus pigmentation varied. Few lens alteration were seen in otherwise healthy chinchilla eyes. Most chinchillas had myelinated discs. Optic nerve cupping was present in 62% of the animals. CONCLUSION: Because of the small amount of tears, the PRT test is recommended for tear measurements in chinchillas. The IOP in chinchillas seems to be quiet is low in comparison to other rodents.
Subject(s)
Chinchilla/anatomy & histology , Diagnostic Techniques, Ophthalmological/veterinary , Eye/anatomy & histology , Ocular Physiological Phenomena , Animals , Female , Male , Pigments, Biological , Reference ValuesABSTRACT
OBJECTIVE: To determine the test-retest reliability and age-related trends of the cervical and ocular vestibular evoked myogenic potential (cVEMP and oVEMP, respectively) responses to air-conducted sound and bone-conducted vibration stimulation. STUDY DESIGN: Prospective study. SETTING: Tertiary referral center. PATIENTS: Fifty-three healthy adults with no hearing or vestibular deficits. INTERVENTION(S): All subjects underwent cVEMP and oVEMP testing in response to sounds (0.1-ms clicks and 500-Hz tone bursts) and vibration (midline forehead taps at the hairline, Fz, with a reflex hammer and a Brüel & Kjaer Mini-Shaker Type 4810). Twelve subjects underwent an additional testing session that was conducted at a mean of 10 weeks after the first one. MAIN OUTCOME MEASURE(S): Test-retest reliability for VEMP response parameters (latency, peak-to-peak amplitude, and asymmetry ratio) were assessed using the intraclass correlation coefficient (ICC). RESULTS: : oVEMP amplitudes had excellent test-retest reliability (ICC > 0.75) for all 4 stimuli; cVEMP amplitudes had excellent reliability for hammer taps and fair-to-good reliability for other stimuli. oVEMP asymmetry ratios had excellent reliability for clicks and fair-to-good reliability (ICC = 0.4-0.75) for other stimuli; cVEMP asymmetry ratios had fair-to-good reliability for clicks and hammer taps. Older subjects (>50 years old) were found to have significantly decreased cVEMP amplitudes in response to clicks, tones, and taps with a Mini-Shaker and significantly decreased oVEMP amplitudes in response to clicks, tones, and taps with a reflex hammer. No age-related changes were found for latencies or asymmetry ratios. CONCLUSION: Overall, oVEMP response parameters demonstrated better test-retest reliability than cVEMP response parameters, but oVEMPs and cVEMPs had similar age-related changes.
Subject(s)
Aging/physiology , Cervical Vertebrae/physiology , Evoked Potentials, Auditory/physiology , Vestibule, Labyrinth/physiology , Acoustic Stimulation , Adult , Aged , Bone Conduction/physiology , Electromyography , Female , Functional Laterality/physiology , Humans , Male , Middle Aged , Ocular Physiological Phenomena , Reproducibility of Results , Vibration , Young AdultABSTRACT
Lutein and zeaxanthin are the only carotenoids present in the eye. They cannot be synthesized de novo and are specifically concentrated in the macula. They appear to have at least two major functions: to filter out blue light and thus prevent ensuing damages to the eye and to act as antioxidants. Infants are particularly at risk from both blue light and oxidative damage to eye tissues. Lutein is present in human milk but is not currently added to infant formulas. Fortifying formulae with lutein in order to match more closely human milk might help protect the infant's sensitive eyes. In adults, the exact pathogenesis of age-related maculopathy remains unknown. Light damage, inflammation, and the disruption of cellular processes by oxidative stress may play an important role in the degenerative process. Manipulation of intake of xanthophylls has been shown to augment macular pigment, therefore it is thought that carotenoid dietary supplements could prevent, delay, or modify the course of age-related maculopathy. However, definite evidence of the effect of carotenoids, the optimal doses to use, and the supplementation duration are still under investigation.
Subject(s)
Eye/physiopathology , Macular Degeneration/prevention & control , Ocular Physiological Phenomena , Xanthophylls/physiology , Carotenoids/administration & dosage , Eye/chemistry , Eye/metabolism , Health Status , Humans , Infant , Infant Formula/chemistry , Infant, Newborn , Inflammation/prevention & control , Lutein/administration & dosage , Lutein/physiology , Macular Degeneration/etiology , Milk, Human/chemistry , Oxidative Stress , Risk Factors , Xanthophylls/administration & dosage , ZeaxanthinsABSTRACT
Less than 20 of the hundreds of carotenoids found in nature are found in the human body. These carotenoids are present in the body from the foods or dietary supplements that humans consume. The body does not synthesize them. Among the carotenoids present in the body, only lutein and its coexistent isomer, zeaxanthin, are found in that portion of the eye where light is focused by the lens, namely, the macula lutea. Numerous studies have shown that lutein and zeaxanthin may provide significant protection against the potential damage caused by light striking this portion of the retina. In the eye, lutein and zeaxanthin have been shown to filter high-energy wavelengths of visible light and act as antioxidants to protect against the formation of reactive oxygen species and subsequent free radicals. Human studies have demonstrated that lutein and zeaxanthin are present in the skin, and animal studies have provided evidence of significant efficacy against light-induced skin damage, especially the ultraviolet wavelengths. Little was known about the protective effects of these carotenoids in human skin until recently. This article reviews the scientific literature pertaining to the effects that lutein and zeaxanthin exhibit in the human eye and skin.
Subject(s)
Lutein/physiology , Ocular Physiological Phenomena , Skin Physiological Phenomena , Xanthophylls/physiology , Humans , Sunlight/adverse effects , ZeaxanthinsABSTRACT
BACKGROUND: Ocular massage is a common technique employed after trabeculectomy to aid filtration. This pilot study compares a novel ocular massage device (MD) with finger massage (FM) after trabeculectomy. The device provides the patient with audio feedback about correctly applied force, and the force applied can be customized for each patient. METHODS: A prospective, randomized study was performed comparing the effects of FM versus MD on intraocular pressure (IOP) and complication rates. All patients were given a standardized tutorial in ocular massage. The efficiency of their massage technique was evaluated at 1 week by having the patient perform the massage in front of the ophthalmologist, with IOP measurements taken before and after massage. Information on bleb morphology, IOP, ocular medications, and complications were recorded on a weekly basis. The patient perspective was recorded by questionnaire at 1 week, 1 month, and 3 months after initiation of the massage. RESULTS: Twenty-five patients were enrolled in the study, 12 randomly assigned to the FM and 13 to the MD groups. Patients in the MD group were much more confident that they were doing the massage correctly (p = 0.009) and reported a greater ease of use and lower pain scores. The mean difference in IOP in the 2 groups was not statistically significant in the first 3 weeks, and IOP after 3 months was statistically similar in both groups. Laser suture lysis was performed in 8 patients (66%) in the FM versus 6 (46%) in the MD group (p = 0.42). Wound leaks developed in 4 patients (3 in the FM group vs. 1 in the MD group, p = 0.32). INTERPRETATION: The massage device shows promise as an adjunctive tool in the postoperative management of trabeculectomies.