Level Of Eye Research Articles

ТРАНСПУПИЛЛЯРНАЯ ТЕРМОТЕРАПИЯ ДИСКА ЗРИТЕЛЬНОГО НЕРВА В ЛЕЧЕНИИ ОККЛЮЗИИ ЦЕНТРАЛЬНОЙ ВЕНЫ СЕТЧАТКИ

Purpose: to make a pathogenetic basis and assessment of the clinical efficacy of transpupillary thermotherapy (TTT)
 of the optic nerve disc in central retinal vein occlusion (CRVO).
 Materials and methods: ophthalmological examination with in-depth study of regional hemodynamics, layered structure
 of the retina, its electrical sensitivity and neural conductivity in 15 patients with CRVO before and after TTT of
 the optic nerve disc.
 Results. After TTT of the optic nerve in patients with CRVO, immediately after treatment visual acuity increased twofold,
 the thickness of the retina significantly decreased in central and peripapillary regions and indices of high-speed
 blood flow of central retinal vein improved. In 3-6 months, retinal thickness, ERG indices and visual evoked potentials
 recovered practically to the level of the fellow eye.
 It was established that after the TTT of the optic nerve the perfusion in the blood vessels of the retina and optic nerve
 has improved, which was accompanied by a decrease in the height and the area of ischemic edema in the peripapillary
 area, improved conduction of impulses along nerve fibers. In contrast to conservative therapy and laser coagulation,
 after a single session of TTT of the optic nerve, visual function improvement occurred in 89 % of cases.
 Conclusions. TTT of the optic disc is a highly effective, pathogenetically proved and safe method of treatment purposefully
 influencing the regional hemodynamics, making possible to achieve positive structural and functional changes
 of the visual system in CRVO.

Bimanual Coordination Development Is Enhanced in Young Females and Experienced Athletes

We characterize bimanual coordination development for the first time in a large sample of children (n = 303) in relation to age, sex, and athletic experience. A further aim is to document the effect of these factors on development to indirectly gain insight into the neural processes that underlie this advanced level of eye–hand coordination. This was a cross-sectional design involving three age groups (range: 9–15 years) that were further separated by sex and level of athletic experience. Participants completed two bimanual tasks and a unimanual control task. While there was no significant change in unimanual movement speed, we observed that females performed the bimanual tasks faster, compared with males. Further, we found that select-level athletes had superior bimanual abilities. Lastly, we found an interaction of sex and skill across age. All groups achieved significant improvement in bimanual coordination with the exception of nonselect males. These data provide a description of normal bimanual coordination development in children during the developmentally crucial ages of 9–15 years, taking account of sex- and experience-related differences.

A Study to Assess the Effectiveness of Warm Compress on level of Dry Eye among Elderly Adults in a selected Old Age Home, Mangalore

Dry eye syndrome is a common disorder of the tear film among elderly adults. Dry eye is caused by decreased tear production, excessive tear evaporation, and an abnormality in the production of mucus or lipids normally found in the tear layer, or a combination of these. Poor production of tears by the lacrimal gland may be a result of age, hormonal changes, or various autoimmune diseases, such as rheumatoid arthritis. Evaporative loss of the watery tear layer is usually a result of an insufficient overlying lipid layer. Dry eyes can usually be diagnosed by the symptoms alone. A slit lamp examination can be performed to diagnose dry eyes and to document any damage to the eye. A Schimer's test can measure the amount of moisture bathing the eye. Health care professionals have the responsibilities to minimise the level of dry eye among elderly adults by various measures such as warm compression, hygienic care, and dietary modification. Moreover, it minimizes the risk of infection and integrated treatment for any associated dry eye syndrome.

검사방법에 따른 우세안의 방향 및 강도의 비교

Purpose: In this study, dominant eye is monitoring and level of dominant was measured in subjective and objective test. Methods: The average age of 21.08 years old of 129 adult (69 male, 60 female) who was no underlying ocular disease were participated in this study. dominant eye was determined by monocular instrument in subjecttive test and using a thin ring () in objective test and level of dominant was measured direction of movement of the thin rim. Results: In the subjective test, there are 100 (77.52%) subjects whose dominant eye was right eye, and 29 (22.48%) subjects whose dominant eye was left eye. In the objective test, 90 (69.77%) subjects had right eye d and 33 (25.58%) subjects had left eye, as dominant eye, and 6 (4.65%) subjects had no dominant eye. Comparison of subjective test and objective test by dominant eye were equal in the 104 (80.62%) subjects, unequal in the 19 (14.73%) and center 6 (4.65%) subjects. The level of dominant eye in objective dominant eye test, there were middle 52 (57.78%) subjects, high 38 (42.22%) subjects in the right eye, and middle 25 (75.76%) subjects, high 8 (24.24%) subjects in the left eye. Conclusions: In this study O - Ring Test hasadvantage of direction and level of dominant eye, and middle or center dominant eye was shown in unequal. From this results, testing of dominant eye should be relationship equal and unequal, also required to be study in dominant eye level in binocular vision.

Effects of mop handle height on shoulder muscle activity and perceived exertion during floor mopping using a figure eight method.

The aim of this study was to investigate effects of mop handle height on electromyographic (EMG) activities of the shoulder muscles and perceived exertion for the shoulder area during floor mopping using a figure eight method. An experimental study with 13 cleaners was conducted using surface EMG and category ratio (CR-10) scale. EMG activity was recorded unilaterally from the upper trapezius, infraspinatus, anterior and middle deltoid muscles. Each subject performed four trials of mopping and each trial consisted of using a different mop handle height (mop adjustment at the level of shoulder, chin, nose and eye) in randomized order. EMG data were normalized to a percentage of maximal voluntary contraction (%MVC). The muscle activities were assessed by estimating the 10th, 50th and 90th percentiles of the amplitude probability distribution function (APDF) of the EMG signals and analysed by linear mixed model analysis. Results showed that shoulder muscle activity was significantly lower when the mop handle height was adjusted to shoulder level or chin level as compared to eye level. These findings were supported by subjective ratings of exertion. It seems that mop handle height adjustment between shoulder and chin level may be recommended as a basis for figure eight mopping.

A revised generic arrangement for the eagle ray family Myliobatidae, with definitions for the valid genera.

The generic arrangement of the eagle rays (Family Myliobatidae) is revised and the genus Pteromylaeus Garman, 1913 is placed into the synonymy of Aetomylaeus Garman, 1908. Definitions are provided for the three valid genera, Aetobatus, Aetomylaeus and Myliobatis, and nomenclatural issues are discussed. Aetobatus differs from the latter two genera in having: a deeply notched nasal curtain, both jaws with a single row of chevron-shaped teeth, broadly rounded pectoral-fin free rear tips, pectoral fins separate from rostral lobe and joining head at level of eye. Aetomylaeus differs from the other two genera in having: pectoral fins separate from rostral lobe and joining head below level of eye, and stinging spine absent or present (usually not well developed when present). Myliobatis differs from the other two genera in having the pectoral fins joined to the rostral lobe by a subocular ridge. A list of valid species is provided, including a list of junior synonyms. Myliobatis australis Macleay, 1881 from southern Australia is placed into the synonymy of the previously considered endemic New Zealand species, M.tenuicaudatus Hector, 1877.

Dual‐axis rotational coronary angiography can reduce peak skin dose and scattered dose: a phantom study

The purpose of this study was to evaluate peak skin dose received by the patient and scattered dose to the operator during dual‐axis rotational coronary angiography (DARCA), and to compare with those of standard coronary angiography (SA). An anthropomorphic phantom was used to simulate a patient undergoing diagnostic coronary angiography. Cine imaging was applied on the phantom for 2 s, 3 s, and 5 s in SA projections to mimic clinical situations with normal vessels, and uncomplicated and complicated coronary lesions. DARCA was performed in two curved trajectories around the phantom. During both SA and DARCA, peak skin dose was measured with thermoluminescent dosimeter arrays and scattered dose with a dosimeter at predefined height (approximately at the level of left eye) at the operator's location. Compared to SA, DARCA was found lower in both peak skin dose (range: 44%–82%, p < 0.001) and scattered dose (range: 40%–70%, p < 0.001). The maximal reductions were observed in the set mimicking complicated lesion examinations (82% reduction for peak skin dose, p < 0.001; 70% reduction for scattered dose, p < 0.001). DARCA reduces both peak skin dose and scattered dose in comparison to SA. The benefit of radiation dose reduction could be especially significant in complicated lesion examinations due to large reduction in X‐ray exposure time. The use of DARCA could, therefore, be recommended in clinical practice to minimize radiation dose.PACS numbers: 87.53.‐j, 87.53.Bn, 87.59.‐e, 87.59.C‐, 87.59.cf, 87.59.Dj

Topical cyclosporine a treatment in corneal refractive surgery and patients with dry eye.

To evaluate preoperative and postoperative dry eye and the effect of cyclosporine A treatment in patients screened for corneal refractive surgery and treated with photorefractive keratectomy (PRK) or LASIK. A consecutive case series of 1,056 patients screened for corneal refractive surgery from 2007 to 2012 was retrospectively analyzed. The level of preoperative and postoperative dry eye and the responsiveness to topical cyclosporine A treatment were assessed. One eye of each patient was randomly selected. A total of 642 eyes progressed to surgery: 524 (81.6%) and 118 (18.4%) underwent LASIK and PRK, respectively. Of 81 (7.7%) diagnosed as having dry eye, 55 were deemed potential candidates and optimized for refractive surgery. Thirty-seven patients with moderate dry eye were treated with topical cyclosporine A prior to surgery (mean duration: 3.2 ± 2.1 months; range: 1 to 12 months). After cyclosporine A treatment, 28 (75.7%) eyes underwent LASIK, 4 (10.8%) eyes underwent PRK, and 5 (13.5%) eyes were not operated on due to failed treatment of dry eye. Postoperative refractive surgery-induced neurotrophic epitheliopathy (LINE in LASIK) was noted in 132 (27.3%) and 12 (11.1%) eyes that underwent LASIK and PRK, respectively. Topical cyclosporine A was prescribed in 79 LASIK-induced and 3 PRK-induced dry eyes. After 12 months or more of cyclosporine A treatment, 5 (6.1%) eyes continued to have dry eye symptoms or signs. Topical cyclosporine A treatment is effective therapy for optimizing patients for refractive surgery and treatment of new onset or worsened dry eye after surgery.

Inter Channel Correlation based Demosaicking Algorithm for Enhanced Bayer Color Filter Array

Demosaicking is a process of obtaining a full color image by interpolating the missing colors of an image captured from a digital still and video cameras that use a single-sensor array. In this study a new Color Filter Array (CFA) is proposed. Which is based on the actual weight of the Human Visual System. It is developed based on the sensitivity level of the human eye to red as 29.9%, green as 58.7% and blue as 11.4%. This study also provides an effective iterative demosaicing algorithm applying a weighted-edge interpolation to handle green pixels followed by a series of color difference interpolation to update red, blue and green pixels. Before applying demosaicking algorithm Gaussian filter is applied to remove noise of the sensor applied image and also enhance the image quality. Experimental results show that the proposed method performs much better than other latest demosaicing techniques in terms of image quality and PSNR value.

Adaptation to vergent and averted eye gaze

Previous adaptation studies have revealed the tuning properties of mechanisms coding left-right averted gaze. Here, Experiment 1 used an adaptation procedure to investigate the mechanisms that encode vergent eye gaze. Following prolonged exposure to convergent or divergent gaze, observers were more likely to categorize smaller gaze deviations in the adapted direction as parallel (i.e., nonvergent). We then examined whether adaptation was occurring to the eyes independently (monocular gaze direction) as opposed to the two eyes as a unitary stimulus (binocular gaze direction). In Experiment 2, we interleaved presentations of convergent and divergent adaptors and tested with either congruent (vergent) or incongruent (left-right) stimuli. Similarly, we interleaved presentations of leftward- and rightward-averted adaptors and tested with congruent (left-right) and incongruent (vergent) stimuli. If adaptation were driven solely by monocular gaze direction, congruent and incongruent adaptation would be similar because, at the level of an individual eye, the stimuli are identical. We find considerable adaptation in the incongruent conditions, consistent with adaptation to individual eye directions. However, we also find greater adaptation in congruent conditions, implicating the involvement of mechanisms that encode binocular gaze direction.

Seeing you through London 2012: eye care at the Olympics

BackgroundProvision of eye care services for competitors and their support teams has become an integral part of the modern Olympic Games.AimTo describe the organisation of the eye clinic at London...

Computation of motion direction in the vertebrate retina

Abstract How direction of image motion is detected as early as at the level of the vertebrate eye has been intensively studied in retina research. Although the first direction-selective (DS) ret­inal ganglion cells were already described in the 1960s and have since then been in the fo­cus of many studies, scientists are still puz­zled by the intricacy of the neuronal circuits and computational mechanisms underlying retinal direction selectivity. The fact that the retina can be easily isolated and studied in a Petri dish-by presenting light stimuli while recording from the various cell types in the retinal circuits-in combination with the ex­tensive anatomical, molecular and physiolog­ical knowledge about this part of the brain presents a unique opportunity for studying this intriguing visual circuit in detail. This ar­ticle provides a brief overview of the histo­ry of research on retinal direction selectivi­ty, but then focuses on the past decade and the progress achieved, in particular driven by methodological advances in optical record­ing techniques, molecular genetics approach­es and large-scale ultrastructural reconstruc­tions. As it turns out, retinal direction selec­tivity is a complex, multi-tiered computation, involving dendrite-intrinsic mechanisms as well as several types of network interactions on the basis of highly selective, likely genet­ically predetermined synaptic connectivi­ty. Moreover, DS ganglion cell types appear to be more diverse than previously thought, differing not only in their preferred direction and response polarity, but also in physiology, DS mechanism, dendritic morphology and, importantly, the target area of their projec­tions in the brain.

Silicone Intubation for the Treatment of Epiphora in Adults With Presumed Functional Nasolacrimal Duct Obstruction

To evaluate the long-term efficacy of silicone intubation in adults with presumed functional nasolacrimal duct obstruction. This retrospective cohort study reviewed adults with unilateral or bilateral epiphora and presumed functional nasolacrimal duct obstruction treated with silicone intubation and followed for signs of treatment failure (defined as persistent epiphora or need for a secondary procedure). Median time to event (failure) after silicone intubation was calculated using Kaplan-Meier survival analysis. Analysis was conducted at the level of the individual eye, with clustering by person taken in account. Cox proportional hazards models were used and adjusted for within-subject variance using a robust sandwich estimator. Forty-four eyes from 30 patients with isolated functional nasolacrimal duct obstruction underwent silicone intubation for epiphora. Mean time to stent removal in 40 of 44 eyes was 4.0 (±4.1) months. Mean duration from the time of stent placement to last follow-up was 2.6 (±2.0) years. Overall success after silicone intubation for resolution of symptoms was 77%. Kaplan-Meier survival analysis for time to event after silicone intubation yielded a median time of 5.7 years. Extrapolated data demonstrated a 96% success rate at 2 years and 85% success rate at 3 years and predicted approximately 50% of patients to have relief of epiphora between 5 and 6 years after silicone intubation. In this study, silicone intubation has good long-term success for relief of epiphora in patients with presumed functional nasolacrimal duct obstruction. This study provides important clinical information to guide management of epiphora in adults with functional nasolacrimal duct obstruction.

Characterization of one time‐sequential stereoscopic 3d display ‐ Part I: Temporal analysis ‐

A method of characterizing time‐sequential stereoscopic 3D displays based on the measurement of the temporal behavior of the systems vs. the grey levels is proposed. An Nvidia 3D vision kit with a 3D‐ready SAMSUNG 2233RZ LCD display is characterized in the paper. OPTISCOPE SA especially designed for the precise measurements of the luminance and temporal behavior of LCD displays was used. The transmittance and response time of the shutter glasses was first evaluated. Then the grey‐to‐grey response times of the display were measured. The 2D and 3D behaviors of the display were then compared. Finally, the temporal behavior of the complete system was modeled, and the grey‐level variations on one view were deduced as a function of the synchronization and level of the other eye. The main sources of imperfection were identified and quantified, and a full computation of the system performances was done.

Accidental fracture of the tip of the Coopdech bronchial blocker during insertion for one lung ventilation

The distal tip of a Coopdech bronchial blocker has a preformed angulation to aid placement in the desired bronchus. We report two cases wherein this design may have resulted in distal tip fracture due to entanglement at the level of the Murphy's eye of the endotracheal tube or at the carina. A 49-yr-old female had a Coopdech bronchial blocker inserted into her right main bronchus for video-assisted thoracoscopic (VAT) lung biopsy. Resistance was encountered on its insertion, followed by confirmation of its position by fibreoptic bronchoscopy. As lung isolation was inadequate, bronchoscopy was repeated during surgery. This showed fracture of the blocker tip that required patient repositioning and insertion of another blocker. In a second incident, a bronchial blocker was inserted into the right main bronchus of a 19-yr-old male for VAT bullectomy. This procedure was performed under continuous fibreoptic guidance. Nevertheless, it was difficult to pass the blocker tip beyond the Murphy's eye of the endotracheal tube, as repeated attempts resulted in its entanglement and fracture. Another blocker was inserted by maneuvering the tip beyond the Murphy's eye. The preformed tip of the Coopdech bronchial blocker can be damaged at the Murphy's eye of the endotracheal tube or at the carina. This can result in tip fracture, especially during insertion into the right main bronchus. Maneuvering the tip away from the Murphy's eye can circumvent this problem. Continuous bronchoscopic guidance should be used as recommended by the manufacturer.

The Weighted Generalized Estimating Equations Approach for the Evaluation of Medical Diagnostic Test at Subunit Level

Sensitivity and specificity are common measures used to evaluate the performance of a diagnostic test. A diagnostic test is often administrated at a subunit level, e.g. at the level of vessel, ear or eye of a patient so that the treatment can be targeted at the specific subunit. Therefore, it is essential to evaluate the diagnostic test at the subunit level. Often patients with more negative subunit test results are less likely to receive the gold standard tests than patients with more positive subunit test results. To account for this type of missing data and correlation between subunit test results, we proposed a weighted generalized estimating equations (WGEE) approach to evaluate subunit sensitivities and specificities. A simulation study was conducted to evaluate the performance of the WGEE estimators and the weighted least squares (WLS) estimators (Barnhart and Kosinski, 2003) under a missing at random assumption. The results suggested that WGEE estimator is consistent under various scenarios of percentage of missing data and sample size, while the WLS approach could yield biased estimators due to a misspecified missing data mechanism. We illustrate the methodology with a cardiology example.

Asymmetries in ocular and cervical responses to sagittal vestibular stimulations.

In rabbits and cats vestibulo-ocular reflex (VOR) and vestibulo-ocular reflex (VCR) were tested in frontal and sagittal planes. The VOR evoked by pitching the animals in side down position showed asymmetric responses with peak eye velocity higher in upward direction than in downward one. This asymmetry was abolished when pitching the animal in upright position. This indicate that the otolithic coactivation, occurring in upright position, symmetrizes canal-induced vertical responses. Vestibulo-ocular reflex evoked by rolling the animals was also symmetric, no matter the animal position was. The electromyographic response of neck muscles to sagittal VCR showed an asymmetric behaviour as far as the timing of extensor and flexor activation was concerning. In fact, the increase of extensor muscle activity was steeper than the decrease and the activation peak was more leading than the inhibition peak. The flexor muscles showed an opposite behaviour. This flexion-extension asymmetry was present either with or without otolithic coactivation. On the contrary, the EMG responses to frontal VCR were much more symmetric. It can be suggested that the upward preponderance is present in the sagittal vestibular circuitry to enhance the upward VCR against a gravity load which opposes head stability during downward head displacements. On the contrary, at level of the eye, in which the gravity does not oppose the responses, the canal-induced vertical asymmetry is cancelled by the otolithic coactivation.

Constructing an Old Extreme Viewpoint

This note records an easy construction of the solution which yields the extremum sought. (For examples of treatments, see [1] and [2], where each treatment contains helpful elements not contained in the other.) We first restrict our attention to the situation shown in FIGURE 1, where the picture extends from B to C on a wall which is perpendicular at F to the horizontal line X which indicates the level of the observer's eye. We let b and c be the distances from F to B and F to C, respectively, and we seek the point P on X at which the angle BPC is a maximum. Our easily constructed solution viewpoint is shown as point A in FIGURE 2. We first show how to locate A, and then show that it is indeed the solution point.

Effects of intraocular irrigation with melatonin on the c-wave of the direct current electroretinogram and on the standing potential of the eye in albino rabbits

The direct current electroretinogram (ERG) and the standing potential (SP) were recorded from both eyes of 14 albino rabbits during intraocular perfusion of one of the eyes, which was vitrectomized, with a recently developed eye irrigation solution (PHS) produced by Pharmacia Ophthalmics. PHS was then replaced by a test solution containing melatonin dissolved in PHS (0.002 microM-200 microM). The fluids were subsequently alternated (PHS - melatonin - PHS). During uniocular irrigation with melatonin the mean c-wave amplitude and SP level of the intact control eye were increased (c-wave +24%, p less than 0.01; SP +0.65 mV, p less than 0.05) compared with the values during the initial perfusion with PHS. In contrast, the c-wave amplitude of the irrigated eye was markedly decreased in many rabbits during perfusion with melatonin compared with the initial PHS, but the mean reduction was small and not statistically significant. The mean SP level was reduced (-1.54 mV, p less than 0.001). This difference between the eyes probably depends on the route by which melatonin reaches the retinal pigment epithelium and thus whether it primarily affects the apical (as in the irrigated eye) or the basal (as in the control eye) pigment epithelial membrane. A peak in the b-wave amplitude was observed in both eyes during uniocular irrigation with melatonin when compared with the amplitude measured during the initial perfusion with PHS (irrigated eye: +27%, p less than 0.001; control eye +18%, p less than 0.002).

Fine structure of the eyes of the interstitial gastropod Fartulum orcutti (Gastropoda, Prosobranchia)

The structure of the ocelli of the interstitial gastropod Fartulum orcutti was studied using light and electron microscopy. Each eye is composed of pigmented, rhabdomeric, and ciliated cells. The pigmented cells contain many electron-dense granules and form a cup that shades the sensory cells from all light except that entering from a dorsal-anterior direction. The rhabdomeric cells are similar to the photosensory cells described for other gastropods. They contain photic vesicles and are characterized by an array of microvilli that project into the interior of the eyecup. In the ciliated cells, the ciliary membranes are greatly expanded and form whorls that lie at the front of the eye, opposite the pigment cup. Axons from the bases of rhabdomeric cells have been traced into the optic ganglion, whereas nerve connections from the ciliated cells have not been observed. We suggest that both the rhabdomeric and ciliated cells are photosensory based on their morphological similarities to eyes in other invertebrates. The significance of ocelli with two types of sensory cells is discussed with regard to 1) phylogenetic schemes based on photoreceptor morphology, and 2) the function of such eyes in the interstitial habitat. In addition, the structure of the eye in Fartulum is compared with the description at the light microscopical level of the eye of a related interstitial gastropod.