Small Visual Field Research Articles

A New Diagnosis of Intestinal Metaplasia in Gastric Mucosa: Convolutional Neural Network Based on Visual Auxiliary Method

Abstract Introduction/Objective Intestinal metaplasia (IM) is a common lesion observed in chronic gastric disease and is thought to be associated with the development of gastric cancer. One of the characteristics of IM is the presence of goblet cells. However, differentiating these inconspicuous goblet cells from glandular cavities and gastric mucus cells using traditional algorithms is inefficient. This paper proposes an interpretable auxiliary diagnosis method for gastric mucosal intestinal metaplasia based on a convolutional neural network(CNN). Methods/Case Report The overall flow chart of the algorithm is shown in Figure 1A. The self-constructed gastric mucosa dataset is utilized in this paper for IM. To improve performance, some modifications are applied to the U-Net. The auxiliary diagnosis process incorporates R34W and R34U for segmenting the glands and IM regions. The R34W represents a dual-resolution input network structure (Figure 1B). For the initial stage of the auxiliary diagnosis, the convolutional neural network calculates patches with both large and small fields for gland region segmentation. Then, the IM glands segmentation network is used to classify regions with and without IM lesions. Results (if a Case Study enter NA) The result of the WSI level mask generated after post-processing is shown in Figure 2A. R34W Net offers significant advantages in differentiating open epithelial structures and proper glands. This network effectively differentiates between proper glands and epithelial regions while maintaining precise segmentation, leveraging high-resolution features in a small visual field. The quantitative indexes of gland segmentation networks are shown in Figure 2B. As part of auxiliary diagnosis, the classification of proper glands with intestinal metaplasia achieves the highest accuracy of 0.95 and AUC of 0.975 in the test datasets (Figure 2C). The area proportion of IM regions generated by CNN is shown in Figure 2D. Conclusion This paper provides a visual auxiliary method based on a CNN for the pathological diagnosis of intestinal metaplasia. The goal is to enhance the speed and accuracy of pathologists in performing this diagnosis. Additionally, we propose a CNN with a dual-resolution input structure, which is utilized for segmenting gastric proper glands.

Invited Session IV: Extended reality--applications in vision science and beyond: Improving augmented reality through perceptual science.

Augmented reality (AR) systems make it possible to present visual stimuli that intermix and interact with people's view of the natural world. But building an AR system that merges stimuli with our natural visual experience is hard. AR systems often suffer from technical and visual limitations, such as small eyeboxes, limited brightness, and narrow visual field coverage. An integral part of AR system development, therefore, is perceptual research that improves our understanding of when and why these limitations matter. I will describe a suite of perceptual studies designed to provide guidance for engineers on the visibility and appearance of wearable optical see-through AR displays. Our results highlight the idiosyncrasies of how our visual system integrates information from the two eyes, the multifaceted nature of perceptual phenomena in AR, and the trade-offs that are currently necessary to create an AR system that is both wearable and compelling.

A new computational model illuminates the extraordinary eyes of Phronima.

Vision in the midwater of the open ocean requires animals to perform visual tasks quite unlike those of any other environment. These tasks consist of detecting small, low contrast objects and point sources against a relatively dim and uniform background. Deep-sea animals have evolved many extraordinary visual adaptations to perform these tasks. Linking eye anatomy to specific selective pressures, however, is challenging, not least because of the many difficulties of studying deep-sea animals. Computational modelling of vision, based on detailed morphological reconstructions of animal eyes, along with underwater optics, offers a chance to understand the specific visual capabilities of individual visual systems. Prior to the work presented here, comprehensive models for apposition compound eyes in the mesopelagic, the dominant eye form of crustaceans, were lacking. We adapted a model developed for single-lens eyes and used it to examine how different parameters affect the model's ability to detect point sources and extended objects. This new model also allowed us to examine spatial summation as a means to improve visual performance. Our results identify a trade-off between increased depth range over which eyes function effectively and increased distance at which extended objects can be detected. This trade-off is driven by the size of the ommatidial acceptance angle. We also show that if neighbouring ommatidia have overlapping receptive fields, spatial summation helps with all detection tasks, including the detection of bioluminescent point sources. By applying our model to the apposition compound eyes of Phronima, a mesopelagic hyperiid amphipod, we show that the specialisations of the large medial eyes of Phronima improve both the detection of point sources and of extended objects. The medial eyes outperformed the lateral eyes at every modelled detection task. We suggest that the small visual field size of Phronima's medial eyes and the strong asymmetry between the medial and lateral eyes reflect Phronima's need for effective vision across a large depth range and its habit of living inside a barrel. The barrel's narrow aperture limits the usefulness of a large visual field and has allowed a strong asymmetry between the medial and lateral eyes. The model provides a useful tool for future investigations into the visual abilities of apposition compound eyes in the deep sea.

Transvaginal single-port laparoscopic-assisted vaginal sacral fixation

: It is estimated that the incidence of pelvic floor dysfunction disease in women over 50 years old is 50%. The aim of treatment for pelvic floor dysfunction is to alleviate symptoms and reconstruct the normal pelvic anatomy in order to improve the quality of life. The surgical methods are various and can be divided into traditional surgery and reconstruction surgery. Reconstruction surgery includes sacral fixation, sacrospinal ligament fixation, high uterosacral ligament suspension, and pelvic floor reconstruction with synthetic mesh. In addition to these, sacrocolpopexy has been widely used in clinical treatment for apical compartment prolapse as one of the classic methods. At present, it is usually completed using an abdominal or laparoscopic method with mesh, but the mesh is a foreign body, which may lead to many complications arising from mesh exposure and erosion. We have been performing transvaginal vaginal sacral fixation with 2 absorbable sliding lines instead of the patch to suspend the vaginal stump on the anterior longitudinal ligament in front of the sacrum. However, due to the need to establish a special surgical position, the use of special lengthening instruments, and the high requirements of teamwork, a limited number of these operations have been completed over the past few years. Recently, different surgical approaches have emerged, especially single-port laparoscopy. With the popularity of the minimally invasive concept and the continuous development of single-port laparoscopic technology, minimal invasiveness, good aesthetic appearance, rapid recovery, and maintaining treatment effectiveness, are the new requirements for our operations. Therefore, we aimed to complete the operation with the aid of transvaginal single-port laparoscopy. The combination of vaginal surgery and laparoscopic surgery avoids the drawbacks in vaginal surgery of a small visual field and exposure difficulties and allows for laparoscopy to be performed under direct vision, which improves the safety of the operation. Furthermore, no scar is left on the body surface, operation-related pain is reduced, the appearance of the body is improved, and rapid recovery is promoted. Here, we describe transvaginal single-port laparoscopic-assisted vaginal sacral fixation.

Genetically-Caused Blindness Reversed with Single Injection of Antisense Therapeutic

Clinical OMICsVol. 8, No. 3 NewsFree AccessGenetically-Caused Blindness Reversed with Single Injection of Antisense TherapeuticPublished Online:18 Jun 2021https://doi.org/10.1089/clinomi.08.03.04AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail A patient with a genetic form of childhood blindness gained vision for more than a year after receiving a single injection of an experimental antisense oligonucleotide, sepofarsen, into the eye.The clinical trial was conducted by researchers at the University of Pennsylvania. According to their study, which appeared in Nature Medicine, the treatment led to marked changes at the fovea, the most important locus of human central vision.Almost a dozen antisense treatments have been approved by the FDA to date. Almost all of these are for orphan diseases, including the drug used in this study. It targets Leber congenital amaurosis (LCA), but is specifically designed for LCA patients with the CEP290 mutation – one of the more commonly implicated gene variants. Patients with this form of LCA suffer from severe visual impairment, typically beginning in infancy.In an international clinical trial led by Penn Medicine researchers Artur Cideciyan, Ph.D., and Samuel Jacobson, M.D., Ph.D., participants received an intraocular injection of sepofarsen. This oligonucleotide works by increasing normal CEP290 protein levels in the eye's photoreceptors.In a previous study, Cideciyan, Jacobson, and collaborators found that injections of sepofarsen every three months resulted in continued vision gains in ten patients.The eleventh patient, whose results are reported in this study, had only one injection and was examined over a 15-month period. Prior to treatment, the patient had reduced visual acuity, small visual fields, and no night vision.After a single injection, more than a dozen measurements of visual function and retinal structure showed large improvements supporting a biological effect from the treatment, which were retained at month 15. The patient's vision reached a peak effect after month two.FiguresReferencesRelatedDetails Volume 8Issue 3May 2021 InformationCopyright © GEN PublishingTo cite this article:Clinical OMICs.May 2021.5-5.http://doi.org/10.1089/clinomi.08.03.04Published in Volume: 8 Issue 3: June 18, 2021PDF download

Clinical Manifestations and Visual Prognosis of Cilioretinal Artery Sparing Central Retinal Artery Occlusion.

PurposeTo investigate the clinical manifestations and prognosis of eyes with cilioretinal artery sparing central retinal artery occlusion (CRAO).MethodsA retrospective study was conducted on 90 eyes diagnosed with complete CRAO, including 16 cases of cilioretinal artery sparing CRAO. Clinical features, visual outcome, papillomacular bundle involvement, and remnant visual field were analyzed according to cilioretinal artery sparing.ResultsAmong eyes with complete CRAO, the proportion of cilioretinal artery sparing CRAO was 17.8% (16 / 90). Mean initial best-corrected visual acuities (BCVAs) (2.04 ± 0.69 vs. 2.34 ± 0.47, p = 0.039) and final BCVAs (1.65 ± 0.87 vs. 2.22 ± 0.84, p = 0.001) were significantly better in eyes of the cilioretinal artery sparing group than the non-sparing group. The proportion with poor visual outcome (final BCVA <20 / 200) was 81.3% in the cilioretinal artery sparing group and 97.3% in the non-sparing group (p = 0.01). In sub-group analysis within cilioretinal artery sparing CRAO eyes, ischemic involvement of the papillomacular bundle at disease onset was significantly more frequent in the poor vision group (BCVA <20 / 200, 12 / 13 [92.3%]) than in the good vision group (BCVA ≥20 / 200, 1 / 3 [33.3%], p = 0.016) and it was associated with preserved central visual field.ConclusionsAlthough cilioretinal artery sparing is common in CRAO and has a better prognosis than complete CRAO, the visual outcome is generally poor and only a small proportion of eyes has preserved small central visual field. Ischemic injury of the papillomacular bundle at the acute stage of CRAO correlates with poor visual outcome and could be a prognostic sign.

Gaze direction as equilibrium: more evidence from spatial and temporal aspects of small-saccade triggering in the rhesus macaque monkey.

Rigorous behavioral studies made in human subjects have shown that small-eccentricity target displacements are associated with increased saccadic reaction times, but the reasons for this remain unclear. Before characterizing the neurophysiological foundations underlying this relationship between the spatial and temporal aspects of saccades, we tested the triggering of small saccades in the male rhesus macaque monkey. We also compared our results to those obtained in human subjects, both from the existing literature and through our own additional measurements. Using a variety of behavioral tasks exercising visual and nonvisual guidance of small saccades, we found that small saccades consistently require more time than larger saccades to be triggered in the nonhuman primate, even in the absence of any visual guidance and when valid advance information about the saccade landing position is available. We also found a strong asymmetry in the reaction times of small upper versus lower visual field visually guided saccades, a phenomenon that has not been described before for small saccades, even in humans. Following the suggestion that an eye movement is not initiated as long as the visuo-oculomotor system is within a state of balance, in which opposing commands counterbalance each other, we propose that the longer reaction times are a signature of enhanced times needed to create the symmetry-breaking condition that puts downstream premotor neurons into a push-pull regime necessary for rotating the eyeballs. Our results provide an important catalog of nonhuman primate oculomotor capabilities on the miniature scale, allowing concrete predictions on underlying neurophysiological mechanisms.NEW & NOTEWORTHY Leveraging a multitude of neurophysiological investigations in the rhesus macaque monkey, we generated and tested hypotheses about small-saccade latencies in this animal model. We found that small saccades always take longer, on average, than larger saccades to trigger, regardless of visual and cognitive context. Moreover, small downward saccades have the longest latencies overall. Our results provide an important documentation of oculomotor capabilities of an indispensable animal model for neuroscientific research in vision, cognition, and action.

Modern Technologies in the Examination of Patients with Optic Nerve Atrophy Due to Multiple Sclerosis

Purpose: to develop an algorithm for testing patients with optic nerve atrophy due to MS using microperimetry with the different functional disorders.Patients and Methods. There were 20 patients (40 eyes) with the correct diagnosis of MS at the age of 33 ± 1.88 years in the study. The BCVA was from 0.1 to 1.0. Microperimetry was done on MP-1 (Nidek technologies, Vigonza, Italy) with the definition of mean sensitivity, stability and type of fixation. We chose the parameters of microperimetry: the research program, the size of the stimulus, the fixation mark and the test mode.Results. The best program for diagnosing central visual field defects was the program macula 12° 10 dB, for paracentral visual field defects – retina 40° 20 dB. The testing was conducted by using a standard stimulus Goldmann III, mark and survey mode is selected individually, according at the various types of functional disorders. The visual acuity was from 0.1 to 0.4 in 11 eyes with optic nerve atrophy. There were revealed absolute or relative defects of the central field of vision and the decreasing of mean sensitivity to 8.21 ± 2.3 dB, unstable central fixation — 71.18 ± 10, 3%. In 29 eyes with optic nerve atrophy and visual acuity 0.5–1.0 have been identified relative small central visual field defects and paracentral visual field defects in the inferior side with a decrease in sensitivity to 15,32 ± 0,84 dB in the area of 6° from the fixing point, stable central fixation 88,96 ± 2,9%.Conclusion. The authors developed an algorithm for testing patients with optic nerve atrophy due to MS. Using the algorithm identified the central and paracentral visual field defects with the decrease in the mean sensitivity.

Effects of Unaugmented Periphery and Vibrotactile Feedback on Proxemics with Virtual Humans in AR.

In this paper, we investigate factors and issues related to human locomotion behavior and proxemics in the presence of a real or virtual human in augmented reality (AR). First, we discuss a unique issue with current-state optical see-through head-mounted displays, namely the mismatch between a small augmented visual field and a large unaugmented periphery, and its potential impact on locomotion behavior in close proximity of virtual content. We discuss a potential simple solution based on restricting the field of view to the central region, and we present the results of a controlled human-subject study. The study results show objective benefits for this approach in producing behaviors that more closely match those that occur when seeing a real human, but also some drawbacks in overall acceptance of the restricted field of view. Second, we discuss the limited multimodal feedback provided by virtual humans in AR, present a potential improvement based on vibrotactile feedback induced via the floor to compensate for the limited augmented visual field, and report results showing that benefits of such vibrations are less visible in objective locomotion behavior than in subjective estimates of co-presence. Third, we investigate and document significant differences in the effects that real and virtual humans have on locomotion behavior in AR with respect to clearance distances, walking speed, and head motions. We discuss potential explanations for these effects related to social expectations, and analyze effects of different types of behaviors including idle standing, jumping, and walking that such real or virtual humans may exhibit in the presence of an observer.

An optimized content-aware image retargeting method: toward expanding the perceived visual field of the high-density retinal prosthesis recipients

Objective. Retinal prosthesis devices have shown great value in restoring some sight for individuals with profoundly impaired vision, but the visual acuity and visual field provided by prostheses greatly limit recipients’ visual experience. In this paper, we employ computer vision approaches to seek to expand the perceptible visual field in patients implanted potentially with a high-density retinal prosthesis while maintaining visual acuity as much as possible. Approach. We propose an optimized content-aware image retargeting method, by introducing salient object detection based on color and intensity-difference contrast, aiming to remap important information of a scene into a small visual field and preserve their original scale as much as possible. It may improve prosthetic recipients’ perceived visual field and aid in performing some visual tasks (e.g. object detection and object recognition). To verify our method, psychophysical experiments, detecting object number and recognizing objects, are conducted under simulated prosthetic vision. As control, we use three other image retargeting techniques, including Cropping, Scaling, and seam-assisted shrinkability. Main results. Results show that our method outperforms in preserving more key features and has significantly higher recognition accuracy in comparison with other three image retargeting methods under the condition of small visual field and low-resolution. Significance. The proposed method is beneficial to expand the perceived visual field of prosthesis recipients and improve their object detection and recognition performance. It suggests that our method may provide an effective option for image processing module in future high-density retinal implants.

A Model Explaining Infantile Esotropia: Dissociated Strabismus as a Result of Sensory Interhemispheric Dissociation and Crossed Dominance in the Brainstem

Over 150 million years, modern reptiles, birds and mammals evolved. Predatory birds and mammals have eyes on the front of their heads. In these animals, binocular correspondence, voluntary eye movements, eye-hand coordination, partial decussation at the optic chiasm and cortical interhemispheric pathways could develop at the cost of a smaller visual field. The subsequent enlargement of the cerebral neocortex and the hemispheric pathways are of central importance in binocular vision, sensory fusion and infantile strabismus. To investigate visual interhemispheric fibers, tractography was used in subjects with infantile esotropia (IE), callosal agenesis and control subjects with normal binocularity. In human callosal agenesis, normal binocularity could be explained by a different interhemispheric connection. In subjects with infantile esotropia, the analyses starting from the primary visual area on one side appeared different from the analysis from the other side. The distribution areas are asymmetrical between sides. Binocularity and alignment not only rely on correspondence between crossed and uncrossed hemi-representations but, in addition the corpus callosum, the most important interhemispheric pathway in placental mammals, seems important in the development of human binocularity. When correspondence is possible between the hemi-representations of the crossed and the uncrossed pathway on both sides of the cortex, the uncrossed pathway finds its way via the corpus callosum toward the contralateral hemi-representation of the same eye. A vertical midline must come out of this process. Meanwhile, however, the other uncrossed pathway strives to find the vertical midline of the other eye. Likely, the corpus callosum is important during the tuning of the pathways involved in sensory fusion. The anterior commissure might be an alternative in callosal agenesis. A failure in the offset will result in strabismus and crossed dominance after V1. Consequently, the normal binocular development of the brainstem (i.e., the superior colliculus), will not take place and latent nystagmus, as well as dissociated divergence, may ensue.

Rat superior colliculus neurons respond to large visual stimuli flashed outside the classical receptive field.

Spatial integration of visual stimuli is a crucial step in visual information processing yet it is often unclear where this integration takes place in the visual system. In the superficial layers of the superior colliculus that form an early stage in visual information processing, neurons are known to have relatively small visual receptive fields, suggesting limited spatial integration. Here it is shown that at least for rats this conclusion may be wrong. Extracellular recordings in urethane-anaesthetized young adult rats (1.5–2 months old) showed that large stimuli of over 10° could evoke detectable responses well outside the borders of ‘classical’ receptive fields determined by employing 2° – 3.5° stimuli. The presence of responses to large stimuli well outside these ‘classical’ receptive fields could not be explained neither by partial overlap between the visual stimulus and the receptive field, nor by reflections or light dispersion from the stimulation site. However, very low frequency (<0.1 Hz) residual responses to small stimuli presented outside the receptive field may explain the obtained results if we assume that the frequency of action potentials during a response to a stimulus outside RF is proportional to the stimulus area. Thus, responses to large stimuli outside RF may be predicted by scaling according to the stimulus area of the responses to small stimuli. These data demonstrate that neurons in the superficial layers of the superior colliculus are capable of integrating visual stimuli over much larger area than it can be deduced from the classical receptive field.

Investigation of aberration characteristics of eyes at a peripheral visual field by individual eye model.

We propose a method of constructing an individual eye model with a large visual field, and then investigate aberration characteristics of eyes in peripheral fields with constructed models. Twelve eyes of different aberrations are selected from 89 myopic eyes. It is shown that astigmatism increases as visual field in a quadratic manner. The variation tendency of defocus can be expressed by the cubic curve for 50% of eyes. For most of the eyes, the variation of spherical aberration shows a quadratic rule within ±24° visual field. Coma exhibits obvious individual differences. The impact of high-order aberrations on vision is mainly at a smaller visual field, and it becomes negligible beyond 24° visual field.

Intersection Recognition and Guide-Path Selection for a Vision-Based AGV in a Bidirectional Flow Network

Vision recognition and RFID perception are used to develop a smart AGV travelling on fixed paths while retaining low-cost, simplicity and reliability. Visible landmarks can describe features of shapes and geometric dimensions of lines and intersections, and RFID tags can directly record global locations on pathways and the local topological relations of crossroads. A topological map is convenient for building and editing without the need for accurate poses when establishing a priori knowledge of a workplace. To obtain the flexibility of bidirectional movement along guide-paths, a camera placed in the centre of the AGV looks downward vertically at landmarks on the floor. A small visual field presents many difficulties for vision guidance, especially for real-time, correct and reliable recognition of multi-branch crossroads. First, the region projection and contour scanning methods are both used to extract the features of shapes. Then LDA is used to reduce the number of the features' dimensions. Third, a hierarchical SVM classifier is proposed to classify their multi-branch patterns once the features of the shapes are complete. Our experiments in landmark recognition and navigation show that low-cost vision systems are insusceptible to visual noises, image breakages and floor changes, and a vision-based AGV can locate itself precisely on its paths, recognize different crossroads intelligently by verifying the conformance of vision and RFID information, and select its next pathway efficiently in a bidirectional flow network.

P 118. A two-center sham-controlled clinical trial of non-invasive alternating current stimulation in optic neuropathy: Sinus pulses are less effective than square

Question Patients with optic nerve damage may achieve improvements of their visual fields and vision-related quality of life after 10-days repetitive transorbital alternating current stimulation (rtACS) with square pulses (Sabel et al., 2011; Gall et al., 2011). Sinus-rtACS resulted in increased alpha power in resting EEG but less pronounced visual field change in optic neuropathy (Schmidt et al., 2012). The present study was carried out to find optimized parameters for rtACS. A double-blinded, randomized, two-center trial (Magdeburg, Berlin) was conducted to compare sinus-rtACS vs. sham stimulation. Sinus-rtACS effect sizes were determined for comparison to square-rtACS that was used in a previous study (Sabel et al., 2011). Methods The present sample consisted of 36 subjects with visual field loss due to optic nerve damage. RtACS was applied between 5 and 30Hz with amplitudes below 800μA. Four stimulation electrodes were placed near closed eyes with return electrode at the occipital pole. Daily session duration was 25–40min. Both groups were subjected to the same electrode montage set-up except that sham-patients received no current stimulation. Main therapeutic outcome was visual field change above baseline. Results Primary analyses revealed an increase of detection ability in defective visual field of 26.3% ( p The within-groups effect size of HRP visual field change after sinus-rtACS was considerably smaller ( d ′ =0.31) than in the previous square-trial ( d ′ =0.63). Additionally, between groups comparisons showed a small effect of d ′ =0.44 after sinus-rtACS while there was a medium effect after square-rtACS ( d ′ =0.67). Resting EEG recorded before and after 10-days stimulation revealed increased power density above occipital cortex (O1,O2) in the alpha and theta band only after rtACS (Fig. 2). Further, a dose–response relation between the applied current strength and HRP visual field change was observed. Conclusions Compared to the previous study with square-rtACS we found smaller visual field improvements after sinus-rtACS. With respect to parameter optimization we therefore chose above-threshold square-rtACS to be used in a subsequent multicenter clinical trial. Band-specific alpha-and theta-entrainment indicated recovery processes within the retinofugal projection. Funding The study was funded by the Otto-von-Guericke University, Magdeburg and EBS Technologies GmbH.

Extraction of Structured Light Stripe in Outdoor Environment for Unmanned System

Structured light extraction is an important problem in 3-D measurement of structured light. Due to traditional structured light extraction methods are mostly applied in small visual field and simple environment. Therefore, a novel method is proposed based on the feature of structured light aiming at the large field and complex surroundings. Firstly, a region of interest (ROI) is obtained through a third sensor in order to reduce calculations and process conveniently. And then, structured light is extracted according to its feature of brightness distribution module and geometrical morphology trait. Experiment shows that this new method not only extracts structured light in such large field with strong background noise well but also reduces the computation to meet real-time requirement.

Ocular outcome and frequency of neurological manifestations in patients with acute posterior multifocal placoid pigment epitheliopathy (APMPPE)

PurposeThe purpose of this study was to describe the visual prognosis as well as the frequency and clinical severity of central nervous system involvement in all acute posterior multifocal placoid pigment epitheliopathy (APMPPE) patients of one centre.MethodsA retrospective database review of all patients and a prospective clinical, ophthalmological and neurological follow-up, if possible, were conducted.ResultsEighteen patients with APMPPE were included with a mean follow-up of 17.1 months. Thirteen patients participated in a follow-up exam. Visual acuity improved in 9 of 18 patients to a mean of 0.17 log minimum angle of resolution (MAR) in the worse eye and remained stable in eight patients (mean, 0.03 logMAR). In the majority of patients, the 30° static perimetry improved at follow-up compared to the initial exams. Still, in up to 50 to 60 %, small visual field defects persisted. Overall, 11 patients (61 %) showed neurologic symptoms of varying severity. The most common neurological symptom was headache in nine (50 %) patients. Other symptoms included paraesthesias, psychosis, vertigo, and, as the most severe complication, stroke due to cerebral vasculitis. Fifteen patients were treated with systemic corticosteroids.ConclusionsVisual prognosis is good in patients with APMPPE, but visual field defects may remain. Neurological signs and symptoms, especially headaches, are frequent in APMPPE and should be taken seriously. Adequate investigations including MRI and CSF examination should be initiated in these patients.

Funktionsdiagnostische Möglichkeiten bei fortgeschrittenem oder präterminalem Glaukom

The visual functional diagnostics for patients with advanced glaucomatous optic neuropathy are subject to challenge. Reduced visual acuity, instable fixation and extensive scotomata frequently lead to incorrect results within the central 30° or 24° field. Static automatic perimetry (SAP) in particular is often hampered by extended examination time and fatigue especially in older patients. Focusing of the examination towards the central 10° field using a dense test grid (2° distance between stimulus locations) allows a more exact assessment of the small remaining central island. Tailoring the examination area towards the central 10° field may be useful even in cases with a mean deviation (MD) of 15dB. In cases of advanced visual field loss kinetic perimetry is superior to static perimetry for various reasons: sharply demarcated visual field defects can be comparatively easily delineated (edge detection); the results are more reliable because fixation can be easily controlled and fatigue is much less pronounced in this interactive examination procedure. However, manual kinetic visual field testing within the central 5° using the conventional Goldmann perimeter is almost impossible due to technical reasons. Semi-automated kinetic perimetry, presenting moving stimuli along interactively defined vectors is a useful tool under these circumstances. The standardized presentation of kinetic stimuli is also feasible within the pericentral region and has particular advantages also with regard to follow-up examinations. On the other hand, detection and delineation of small visual field remnants are comparatively difficult to handle with this kind of vector-based kinetic perimetry.

Local robot navigation based on an active visual short-term memory

Vision devices are today one of the most often used sensory elements in autonomous robots. Some of their hindrances are the difficulty in extracting useful information from the captured images and the small visual field of regular cameras. Visual attention systems and active vision may help to overcome them. This work proposes a dynamic visual memory to store the information gathered from a continuously moving camera onboard the robot and an attention system to choose where to look at with such mobile camera. The visual memory is a collection of relevant task-oriented objects and 3D segments, and its scope is wider than instantaneous field of view of the camera. The attention system takes into account the need to reobserve objects in the visual memory, explore new areas and test hypothesis about object existence in the robot surroundings. The system has been programmed and validated in a real Pioneer robot that uses the information in the visual memory for navigation tasks.

Human locomotion through a multiple obstacle environment: strategy changes as a result of visual field limitation

This study investigated how human locomotion through an obstacle environment is influenced by visual field limitation. Participants were asked to walk at a comfortable pace to a target location while avoiding multiple vertical objects. During this task, they wore goggles restricting their visual field to small (S: 40° × 25°), medium (M: 80° × 60°), large (L: 115° × 90°), or unlimited (U) visual field sizes. Full-body motion capture was used to extract for each trial the mean speed, pathlength, mean step width, magnitude of head rotation and head mean angular speed. The results show that compared with the U condition, the M and L conditions caused participants to select a wider path around the obstacles without slowing down or altering step width. However, the S condition did slow down the participants, and increased both their step width and path length. We conclude that only for the S condition, balancing problems were substantial enough to spend more energy associated with increased step width. In all cases, participants choose to optimize safety (collision avoidance) at the cost of spending more energy.