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Eye fatigue (Asthenopia) relief by astaxanthin
Abstract
Astaxanthin is a naturally occurring carotenoid in a wide variety of living organisms such as salmon, shrimp, crab, and red snapper. Approximately 90% of the astaxanthin in krill is found in the eye. Asthenopia, or eye fatigue, is an ophthalmological condition with nonspecific symptoms such as eye pain, eye strain, blurred vision, headache, and shoulder stiffness. Symptoms often occur after reading, computer work, or other activities that involve visual display terminals (VDT). More recently, the advances of information technology (IT), software, and electronics have led to the widespread and habitual use of VDT resulting in higher visual fatigue complains and more sufferers. There is, however, no effective therapeutic approach to date. Eye fatigue is usually caused by straining the ciliary body, the eye muscle responsible for accommodation. We previously reported a randomized double-blind placebo controlled study using VDT workers (n=25 treated vs. 23 placebo). 6mg/day astaxanthin supplementation for 4-weeks significantly improved eye fatigue measuring ocular accommodation by the objective instrument and subjective individual assessment. Here we report further 4 clinical studies with the different measurements and an animal study. The same source of astaxanthin, extract derived from the microalgae Haematococcus pluvialis, was used for all of the studies. The first clinical study was performed under randomized double-blind placebo controlled cross-over conditions using 10 healthy subjects. After a 20-minute near visual task, accommodation contraction and relaxation times were extended in both the astaxanthin and placebo groups. However, accommodation relaxation time in the placebo was significantly longer than in the astaxanthin group, and accommodative contraction and relaxation times after a 10-minute rest in the placebo were also significantly longer those in the astaxanthin group. In the second study, the effects of astaxanthin on accommodative recovery derived from a rest after VDT work were studied using 10 healthy volunteers. 6mg/day astaxanthin supplementation for 2-weeks led to a significant relief in accommodative fatigue induced by 30-minutes of IT work (Nintendo Game Boy). In the third study, 22 middle-aged and elder subjects (mean age: 53.9 years) with complaints of eye strain received 6mg/day astaxanthin. Results showed that the pupillary constriction ratio at week 4 was significantly increased compared to that at week 0. The forth clinical study, using 10 healthy subjects, was performed to investigate the effects of visual fatigue on reaction times. Visual fatigue significantly increases reaction time; however 6 mg/day astaxanthin supplementation for 4-weeks was shown to significantly decrease reaction time. We also investigated the intraocular pharmacokinetics of astaxanthin in an albino rabbit. After 100mg/kg astaxanthin administration in a single dose, astaxanthin was detected in the ciliary body as well as the serum at Tmax of 24h and 9h and Cmax of 79.3ng/g and 61.3ng/ml, respectively. Based on the studies it is suggested that astaxanthin supplementation might be a practical and beneficial approach for eye fatigue relief.
... The main benefits for human health. "Eye fatigue relieve" (Yamashita, 2009), "skin aging defence" (anti-photoaging) (Tominaga et al., 2012) and "muscle resilience" (sports performance enhancement) (Yamashita, 2011;Earnest et al., 2011) have been most clinically substantiated. ...
The effect of Astaxanthin powders on biological, health and growth parameter of common carp Cyprinus carpio L. Fish weight varied between (59.2-66.4 g) were studied for 10 weeks. Four treatments (triplicate) were employed as follows: T1: Diet without any addition, T2: adding 2.5 g Astaxanthin powders /kg diet, T3: adding 5 g Astaxanthin powders /kg diet, T4: adding 7.5 g Astaxanthin powders /kg diet. Twice daily feeding at 9:00 a.m. and 2:00 p.m. Blood samples were taken from the caudal vein of fish. The results showed no significant difference between treatments in terms of biological parameter (p>0.05). The results showed a significant difference between treatments in terms of Health indices, including gonadosomatic, but no significant difference (p>0.05) hepatosomatic, spleenosomatic index and Gill index. The results showed a significant difference between treatments in terms of growth performance (p<0.05), including weight gain, Relative growth rate and Specific growth rate. Group results of blood factors showed that between Granulocytes, Lymphocytes and Monocytes there was no significant difference between treatments (p>0.05). Lastly, we found that diets containing higher levels of astaxanthin powders improve the growth performance, biological and GSI in common carp Cyprinus carpio L. Keywords: common carp Cyprinus carpio L., Astaxanthin powders, Biological and Health parameter and growth performance. ABSTRAK Efek Astaxanthin bubuk pada biologis, kesehatan dan pertumbuhan parameter Ikan Mas Cyprinus carpio L. Berat ikan variasi antara (59.2-66.4 GM) dipelajari selama 10 minggu. Empat perlakuan (tiga replikasi) yang digunakan sebagai berikut: T1: diet tanpa penambahan, T2: ditambahkan 2.5 gr bubuk Astaxanthin /kg diet, T3: ditambahkan 5 g bubuk Astaxanthin /kg diet, T4: ditambahkan 7.5 g bubuk Astaxanthin /kg diet. Pemberian pakan dilakukan pada 9:00 a.m dan 2:00 p.m. Sampel darah diambil dari vena caudal ikan. Hasilnya menunjukkan tidak ada perbedaan yang signifikan antar perlakuan dalam hal parameter biologis (p>0.05). Hasilnya menunjukkan perbedaan yang signifikan antara perawatan dalam hal Indeks Kesehatan, termasuk gonadosomatik, tetapi tidak ada perbedaan yang signifikan (p>0.05) hepatosomatic, indeks spleenosomatic dan indeks Gill. Hasilnya menunjukkan perbedaan yang signifikan antara perawatan dalam hal kinerja pertumbuhan (p<0.05), termasuk penambahan berat badan, tingkat pertumbuhan relatif dan tingkat pertumbuhan spesifik. Hasil pengelompokan faktor darah menunjukkan bahwa antara Granulosit, Limfosit dan Monosit tidak memiliki perbedaan yang signifikan antar perlakuan (p>0.05). Terakhir, kami menemukan bahwa diet yang mengandung tingkat yang lebih tinggi dari bubuk Astaxanthin Omni-Akuatika, 15 (2): 52-59, 2019 ISSN: 1858-3873 print / 2476-9347 online Research Article journal homepage: http://ojs.omniakuatika.net 53 Saraddin et al., Biological and Health impact of Astaxanthin powders meningkatkan kinerja pertumbuhan, biologis dan Gonadosomatic index % (GSI) yang umumnya digunaan untuk Cyprinus carpio L. Kata Kunci: ikan mas Cyprinus carpio L., serbuk Astaxanthin, parameter biologis, kesehatan dan kinerja pertumbuhan.
... The main benefits for human health. "Eye fatigue relieve" (Yamashita, 2009), "skin aging defence" (anti-photoaging) (Tominaga et al., 2012) and "muscle resilience" (sports performance enhancement) (Yamashita, 2011;Earnest et al., 2011) have been most clinically substantiated. ...
The effect of Astaxanthin powders on biological, health and growth parameter of common carp Cyprinus carpio L. Fish weight varied between (59.2-66.4 g) were studied for 10 weeks. Four treatments (triplicate) were employed as follows: T1: Diet without any addition, T2: adding 2.5 g Astaxanthin powders /kg diet, T3: adding 5 g Astaxanthin powders /kg diet, T4: adding 7.5 g Astaxanthin powders /kg diet. Twice daily feeding at 9:00 a.m. and 2:00 p.m. Blood samples were taken from the caudal vein of fish. The results showed no significant difference between treatments in terms of biological parameter (p>0.05). The results showed a significant difference between treatments in terms of Health indices, including gonadosomatic, but no significant difference (p>0.05) hepatosomatic, spleenosomatic index and Gill index. The results showed a significant difference between treatments in terms of growth performance (p<0.05), including weight gain, Relative growth rate and Specific growth rate. Group results of blood factors showed that between Granulocytes, Lymphocytes and Monocytes there was no significant difference between treatments (p>0.05). Lastly, we found that diets containing higher levels of astaxanthin powders improve the growth performance, biological and GSI in common carp Cyprinus carpio L. Keywords: common carp Cyprinus carpio L., Astaxanthin powders, Biological and Health parameter and growth performance. ABSTRAK Efek Astaxanthin bubuk pada biologis, kesehatan dan pertumbuhan parameter Ikan Mas Cyprinus carpio L. Berat ikan variasi antara (59.2-66.4 GM) dipelajari selama 10 minggu. Empat perlakuan (tiga replikasi) yang digunakan sebagai berikut: T1: diet tanpa penambahan, T2: ditambahkan 2.5 gr bubuk Astaxanthin /kg diet, T3: ditambahkan 5 g bubuk Astaxanthin /kg diet, T4: ditambahkan 7.5 g bubuk Astaxanthin /kg diet. Pemberian pakan dilakukan pada 9:00 a.m dan 2:00 p.m. Sampel darah diambil dari vena caudal ikan. Hasilnya menunjukkan tidak ada perbedaan yang signifikan antar perlakuan dalam hal parameter biologis (p>0.05). Hasilnya menunjukkan perbedaan yang signifikan antara perawatan dalam hal Indeks Kesehatan, termasuk gonadosomatik, tetapi tidak ada perbedaan yang signifikan (p>0.05) hepatosomatic, indeks spleenosomatic dan indeks Gill. Hasilnya menunjukkan perbedaan yang signifikan antara perawatan dalam hal kinerja pertumbuhan (p<0.05), termasuk penambahan berat badan, tingkat pertumbuhan relatif dan tingkat pertumbuhan spesifik. Hasil pengelompokan faktor darah menunjukkan bahwa antara Granulosit, Limfosit dan Monosit tidak memiliki perbedaan yang signifikan antar perlakuan (p>0.05). Terakhir, kami menemukan bahwa diet yang mengandung tingkat yang lebih tinggi dari bubuk Astaxanthin Omni-Akuatika, 15 (2): 52-59, 2019 ISSN: 1858-3873 print / 2476-9347 online Research Article journal homepage: http://ojs.omniakuatika.net 53 Saraddin et al., Biological and Health impact of Astaxanthin powders meningkatkan kinerja pertumbuhan, biologis dan Gonadosomatic index % (GSI) yang umumnya digunaan untuk Cyprinus carpio L. Kata Kunci: ikan mas Cyprinus carpio L., serbuk Astaxanthin, parameter biologis, kesehatan dan kinerja pertumbuhan.
... The main benefits for human health. "Eye fatigue relieve" (Yamashita, 2009), "skin aging defence" (anti-photoaging) (Tominaga et al., 2012) and "muscle resilience" (sports performance enhancement) (Yamashita, 2011;Earnest et al., 2011) have been most clinically substantiated. ...
The effect of astaxanthin powders on biological, health and growth parameter of common carp Cyprinus carpio L. Fish weight varied between (59.2 –66.4gm)were studied for 10 weeks. four treatments(three replicates/treatment) were employed as follows: T1: Diet without any addition, T2: adding 2.5 gm astaxanthin powders / kg diet, T3: adding 5 gm astaxanthin powders / kg diet, T4: adding 7.5gm astaxanthin powders / kg diet. Twice daily feeding at 9:00 a.m. and 2:00 p.m. should be considered that the feeding rate of biomass weight after each took biometrics. Finally, blood samples were taken from the caudal vein of fish. The results showed no significant difference between treatments in terms of biological parameter (p>0.05). The results showed significant difference between treatments in terms of body indices, including Gonadosomatic, but no significant difference (p>0.05) Hepatosomatic, Spleenosomaticindex and Gill index. The results showed a significant difference between treatments in terms of growth performance (p<0.05), including weight gain, Relative growth rate and Specific growth rate. Group results of blood factors showed that between Granulocytes, Lymphocytes and Monocytes there was no significant difference between treatments (p>0.05). Lastly, we found that diets containing higher levels of Astaxanthin powders improve the growth performance, biological and GSI in common carp Cyprinus carpio L.
... Figure 2 shows the main benefits for human health. "Eye fatigue relieve" [10], "skin aging defense" (anti-photoaging) [11] and "muscle resilience" (sports performance enhancement) [12,13] have been most clinically substantiated. There were the cases that the administration improved the cardiac function in the heart failure patients who is difficult to control with drug therapy and in the patients whose activity levels were reduced because of chronic heart failure resulting in enhancing their daily activity levels and QOL. ...
Astaxanthin is a red pigment that belongs to the carotenoid family like β-carotene. And it’s found in seafood such as crustaceans: shrimp and crabs and fish: salmon and sea bream. Recently, astaxanthin has been reported to have antioxidant activity up to 100 times more potent than that of vitamin E against lipid peroxidation and about 40 times more potent than that of β-carotene on singlet oxygen quenching. Astaxanthin does not show any pro-oxidant activity and its main sight of action is on/in the cell membrane. Various important benefits to date have suggested for human health such as immunomodulation, anti-stress, anti-inflammation, LDL cholesterol oxidation suppression, enhanced skin health, improved semen quality, attenuating eye fatigue, sport performance and endurance, limiting exercised induced muscle damage, suppressing the development of life-style related diseases such as obesity, atherosclerosis, diabetes, hyperlipidemia and hypertension. Nowadays, the research and demand for natural astaxanthin in human health application are explosively growing worldwide. Especially, the clinicians use the astaxanthin extracted from the microalgae, Haematotoccus pluvialis as an add-on supplementation for the patients who are unsatisfied with the current medications or who can’t receive any medications because of their serious symptom. For example, the treatment enhances their daily activity levels or QOL in heart failure or benign prostatic hypertrophy/lower urinary tract symptom patients Other studies and trials are under way on chronic diseases such as non-alcoholic steatohepatitis, diabetes and CVD. We may call astaxanthin “a medical food” in the near future.Keywords: astaxanthin, medical food, Haematococcus, add-on supplementation
Xanthophylls such as canthaxanthin, astaxanthin, zeaxanthin, lutein and tunaxanthin that are widely distributed in Nature have been found to be precursors of retinoids not only in freshwater fish and marine fish (yellowtail) but also in mammals (rat). Reductive metabolic pathways from 3-dehydroretinol to retinol and from 3-dehydroretinal to retinal have been newly discovered by feeding experiments with rat and yellowtail, respectively.
The collaboration of Fergus Campbell, Gerald Westheimer and John Robson in the 1950s produced insight into the nature of accommodation microfluctuations and instigated work which has led to the current view that the nominally steady-state accommodation response exhibits temporal variations which can be characterized by two dominant regions of activity: a low-frequency component (LFC less than 0.6 Hz) and a high-frequency component (HFC greater than or equal to 1.0 less than or equal to 2.3 Hz). A functional role has been attributed to these microfluctuations as they offer a means by which a directional cue could be derived from an even-error stimulus. However, there is no consensus regarding the respective contribution made by each of the dominant components in the accommodation control process. Using a newly-designed measurement and recording system we have conducted a series of experiments to investigate the nature and aetiology of the microfluctuations. The incidence and magnitude of microfluctuations in LFCs and HFCs for central and peripheral lens zones were investigated while five young emmetropic subjects viewed a near target. The form of the power spectra of the fluctuations was found to be similar for central and peripheral zones although an overall reduction in magnitude was observed in the periphery. The HFCs are thus a consistent feature of microfluctuations in central zones and not, as previously suggested, merely a spurious feature of peripheral zones. A significant between-subject variation in the location of HFCs was found and led us to consider the relationship between HFCs and other physiological systems which provide intraocular rhythmic variation.(ABSTRACT TRUNCATED AT 250 WORDS)
A questionnaire was used to evaluate asthenopia in 30 normal subjects (Ss). Then, each S experienced 3 min of continuous alternating convergent and divergent fusional vergence or a control condition which was identical to the experimental condition, but without any vergence demand, i.e., version. The stimulus was a computer-generated flat fusion red-blue anaglyph picture of a horse. The order of vergence and version conditions were randomized. Asthenopia measures and maximal fusional vergence ranges measures were repeated immediately after each condition. Results indicated a significantly higher rating of asthenopia after induced vergence than version. There were no differences in maximal fusional vergence ranges or recovery values after the two conditions. Correlations between pretreatment asthenopia scores and asthenopia scores after either induced vergence or version were also not significant. Post hoc analyses of Ss grouped as having either high or low asthenopia, according to baseline ratings, revealed no significant differences in vergence or version conditions. Alternative hypotheses for these results are presented.
Some standards for work at visual display units (VDU) recommend viewing distances of about 50 cm. The present study investigated whether or not visual strain is lower at viewing distances greater than 50 cm. Specifically, the question of whether the optimal viewing distance is determined by the individual's accommodation in a condition without fixational stimulus, the so-called dark focus, was studied. Two groups of subjects with mean dark focus of about 1 dioptre (D) and 2 D, respectively, performed a search and comparison task for 2 hours at a VDU at viewing distances of 50 cm and 100 cm. The characters on the VDU subtended the same visual angle in both conditions. Visual strain was evaluated by recording the subjects' performance during VDU work, their judgements of the comfort of the viewing distances, and their subjective estimates of visual strain; further, several oculomotor functions were measured throughout the sessions. In both groups, visual strain was higher in the 50 cm condition, and the longer distance of 100 cm was preferred. Thus, irrespective of the individual's dark focus, visual strain can be reduced by using viewing distances greater than those recommended in some standards.When the VDU was near, visual strain in near-dark-focus subjects (2D) was lower than in far-dark-focus subjects (1 D) thus, the strain of the accommodative system alone seems to be minimal when the viewing distance is made to agree with the dark focus. However, since both groups had a far dark convergence and both showed less visual strain at 100 cm, the stress on the convergence system may be the crucial factor for visual strain.
A newly developed "Near Triad Meter" is a useful tool to record the dynamics of pupils and horizontal eye movements in both eyes simultaneously with the accommodative stimuli. The responses show insufficiency or strain for accommodation. In this study the objective accommodative power (in diopters, D) is calculated by the measurement of pupillary constriction-ratio(CR) and compared in 4 age groups to find the age-related decrement of diopter values.
A clearly visible accommodative target was moved back-and-forth from 50 cm to [near point + 1 D] (maximum accommodative stimulus; MAS). The speed was regulated constant for diopter movement. Pupillometry and eye tracker were recorded simultaneously with MAS in both eyes together. Three trials were done on 42 volunteers in each age group from 20-year-olds to 50-year-olds and the most reliable recording was used to measure the CR. Eighteen well-responding volunteers were selected to make the standard curves of CR by step-by-step accommodative stimuli. The mean CRs of initial tests with MAS were applied to the age-matched standard curves to calculate the maximum accommodative diopter value.
The mean CRs versus MAS in each age group were 48%/7.2 D in the 20-year group, 46%/6.9 D in the 30-year group, 35%/3.6 D in the 40-year group, and 33%/3.1 D in the 50-year group. The mean values of CR were applied to age-matched standard curves to obtain the maximum accommodative power, which was 8.0 D in the 20-year group, 9.1 D in the 30-year group, 3.4 D in the 40-year group, and 4.1 D in the 50-year group. The 20- and 30-year olds showed equal power statistically, The remarkable age-dependent difference was calculated quantitatively.
The dynamics of near response revealed the individual summation of accommodative power including depth of focus, and accommodative vergence objectively and quantitatively. This method is useful for understanding the quality of accommodative insufficiency and also the quantity of accommodative width, including presbyopia.
We measured the accommodative response in order to investigate the influence of a visual function when gazing at stereoscopic images presented on a three dimensional display.
Accommodative step responses were measured using an infrared optometer, setting the far target at the distance of 1 m and the near target at the distance of 50 cm. The step response of the right eye was examined 6 times at 10-second intervals. The far target was a starburst as a real image and the near target was a white circle on a random dot background on a parallax barrier system three-dimensional display as a stereoscopic image generated with a 90-min arc binocular crossed disparity(+1.5 degrees) and a 90-min arc binocular uncrossed disparity (-1.5 degrees), and a 0-min disparity (0 degree). The near target was presented in 4 ways: 1. -1.5 degrees disparity alone, 2. 0-min disparity alone, 3. +1.5 degrees disparity alone, and 4. +1.5 degrees and -1.5 degrees disparity alternately.
In conditions 1 to 3, the mean +/- standard deviation values of the accommodative response were 0.59 +/- 0.16 D, 0.72 +/- 0.11 D, and 1.03 +/- 0.21 D, respectively. The accommodative response was very large at the disparity of +1.5 degrees compared with the disparity of 0 degree (p = 0.0300). It was not significant although there was a tendency to become small at the disparity of -1.5 degrees (p = 0.0707). In condition 4, the mean +/- standard deviation values of the accommodative response were 0.62 +/- 0.12 D in the condition of -1.5 degrees and 1.03 +/- 0.26 D in condition +1.5 degrees with significant difference (p = 0.0122).
The over accommodation response is induced when gazing at a stereoscopic image under the condition of binocular crossed disparity. This indicates that gazing at stereoscopic images has ill effects on the accommodative system.
To conduct an experimental investigation of the effect of accommodative relaxation using far point shift stimuli for the reduction of asthenopia.
Twenty-two female students accommodated to a far point shift stimuli during a 2-min period immediately after a 15-min sustained task on a three-dimensional display. Before and after the trial, their accommodative step response and symptoms were assessed. The far point shift stimuli in the optical system, which were presented on a refractometer, were created by moving the target scenery images from far to near, lineally centred about the far point position of each eye. During 2 min of fixating on the far point shift stimuli, changes in refraction were recorded in the same eye.
While looking at the far point shift stimuli, 10 of 22 subjects had changes in refraction that showed a hypermetropic shift, and the other 12 subjects had changes in refraction that showed a myopic shift. The time taken for the accommodative step response from far to near post-trial in the myopic shift group was markedly prolonged, and the accommodative lag at the far target in the optometer was significantly increased. In the myopic shift group, the symptoms of "eye fatigue", "eye pain", "eye heaviness", and "eye dryness" also increased after the trial. In the hyperopic shift group, however, only the symptom of "eye dryness" increased, with no reduction of accommodation function.
We suggest that accommodative relaxation by accommodative far point shift stimuli is effective in the reduction of asthenopia.