Visual field inhomogeneous in brain-computer interfaces based on rapid serial visual presentation

Objective. Visual attention is not homogeneous across the visual field, while how to mine the effective EEG characteristics that are sensitive to the inhomogeneous of visual attention and further explore applications such as the performance of brain-computer interface (BCI) are still distressing explorative scientists. Approach. Images were encoded into a rapid serial visual presentation (RSVP) paradigm, and were presented in three visuospatial patterns (central, left/right, upper/lower) at the stimulation frequencies of 10Hz, 15Hz and 20Hz. The comparisons among different visual fields were conducted in the dimensions of subjective behavioral and EEG characteristics. Furthermore, the effective features (e.g. SSVEP, N2pc and P300) that sensitive to visual-field asymmetry were also explored. Results. The visual fields had significant influences on the performance of RSVP target detection, in which the performance of central was better than that of peripheral visual field, the performance of horizontal meridian was better than that of vertical meridian, the performance of left visual field was better than that of right visual field, and the performance of upper visual field was better than that of lower visual field. Furthermore, stimuli of different visual fields had significant effects on the spatial distributions of EEG, in which N2pc and P300 showed left-right asymmetry in occipital and frontal regions, respectively. In addition, the evidences of SSVEP characteristics indicated that there was obvious overlap of visual fields on the horizontal meridian, but not on the vertical meridian. Significance. The conclusions of this study provide insights into the relationship between visual field inhomogeneous and EEG characteristics. In addition, this study has the potential to achieve precise positioning of the target's spatial orientation in RSVP-BCIs.

Risk Factors for Visual Field Progression in New-diagnosed Exfoliation Glaucoma Patients in Sweden.

Purpose: The present study aimed to identify risk factors for visual field progression in new-diagnosed exfoliation glaucoma patients. Methods: Prospective non-randomized cohort study. The study included patients with new-diagnosed exfoliation glaucoma. All patients were followed for at least three years with reliable visual fields. Both risk factors at inclusion and during the three years follow-up were considered. For inclusion, five reliable visual fields were needed. Exfoliation glaucoma was defined based on the European Glaucoma Society guidelines. Visual field evaluation was performed using the 24-2 strategy of the Humphrey Field Analysis. Outcomes: Visual field progression. Three different approaches were used: mean deviation (MD), visual field index (VFI), and guided progression analysis (GPA). Results: The results were different in the three different models used (MD, VFI and GPA). The only variable that showed a significant association in the three models was age (p= 0.004; p=0.006; p=0.04). Significant variables in two models were: IOP at diagnose (p=0.02; p=0.04), IOP reduction in absolute terms (p=0.006; p=0.003), IOP reduction in relative terms (%) (p=0.04; p=0.009) and number of medicines (p=0.02; p=0.002). Significant variables in one model were: family history (p=0.04), smoking (p=0.03), cataract surgery (p=0.04) and SLT treatment (p=<0.001). Conclusion: Exfoliation glaucoma is fast progressive glaucoma. Age at diagnosing must be considered. Significant IOP reduction must be achieved to slow down progress in exfoliation glaucoma. The use of SLT treatment should be advised in exfoliation glaucoma patients.

Pseudoexfoliation Glaucoma and its Systemic Association: A Clinical Study

Pseudoexfoliation [PXF] being a age related elastotic process is a well known entity among all ophthalmologists. PXF is most common form of secondary glaucoma. Objective: To study the clinical presentations and response to treatment of PXF glaucoma and also to throw light on its systemic associations. Methods: A total of 70 eyes of PXF glaucoma was considered for the study in duration of 6 months from june to November 2021 at a tertiary care center. All patients underwent detailed ophthalmic evaluation along with gonioscopy, optic disc assessment, visual fields and intraocular pressure. Based on all these , patients were graded as mild, moderate and advanced glaucoma and treated accordingly either with medical or surgical line of management. Patients were followed up for a duration of 6 months. ECG, echocardiography and dermatological evaluation of all the patients were done. Results: Mean age of 70 patients was 52.2 years and there was male preponderance .Powdery greyish white pseudoexfoliative material on pupillary margin was seen in 41 eyes[58.5%] and on anterior capsule was seen in 19 eyes[27.1%]. IOP in these 70 patients ranged between 14 to 40mmHg. Gonioscopy showed exfoliative material deposition in 14 eyes[20%] and increased pigmentation of trabecular meshwork in 44 eyes[62.85%]. Also, it revealed narrow angle( grade 1&2) in 6 eyes and open angle (grade 3&4) in rest .Visual filed changes were present in 57 of 70 eyes with PXF glaucoma. Optic disc changes in PXF glaucoma also showed variations with 17 eyes having CD ratio of<0.5,while 38 eyes had a cupping between 0.6-0.8. Eleven eyes showed advanced cupping of >0.8 while 4 eyes had glaucomatous optic atrophy.60 eyes were treated with medical line while 10 eyes were managed surgically. 4 patients had dermal nodules and diastolic dysfunction was noted in 31 patients. Conclusion: PXF confers a significantly higher risk of developing glaucoma in comparison with the general population and needs close monitering. PXF glaucoma and its systemic associations also has to be considered Keywords: PXF, pseudoexfoliative, ECG

Testing Visual Fields in Children

Visual fields in the pediatric population are an essential part of the eye exam that remain challenging to even the most experienced clinicians. Becoming educated in the multiple ways a child's visual field can be tested regardless of age and cognitive and physical abilities will allow the clinician to gain better insight into the child's function and in some cases, allow the clinician to identify pathological or neurological anomalies in the visual pathway. Gross visual field or functional visual field extent can be estimated by tests such as confrontation visual field testing, finger counting field testing, and white sphere kinetic perimetry. For threshold measurements of a child's visual fields, the Goldmann perimeter, or the more advanced computerized tests such as the Humphrey perimeter, Octopus perimeter, or frequency doubling technology perimeter can be used. Modifications can be made to certain tests to better suit the child's cognitive and physical abilities. The chapter covers different methods of visual field testing specific for the pediatric population.

Decompensated Superior Oblique Palsy Secondary to Bilateral Nutritional Optic Neuropathy Following Bariatric Surgery

Optic neuropathy can occur secondary to nutritional deficiencies in patients who have undergone bariatric surgery. We present a unique case of a 39-year-old man, claiming to be generally healthy, who presented with intermittent vertical diplopia and bilateral decreased vision in each eye. Visual acuity was 6/18 in the right eye and 6/12 in the left eye. Ishihara testing was defective for both eyes. Automated visual fields showed a severe generalized reduction in sensitivity in both eyes. The patient had a left head tilt and a right intermittent hypertropia of 30 prism diopters in primary position. CT of the orbits revealed a right superior oblique of small caliber. On further questioning, the patient admitted to a history of bariatric surgery 7 years prior to presentation with failure to take any nutritional supplements. Blood work demonstrated deficiencies in folate, thiamine, and copper. Within 6 months of initiating nutritional supplements, the vision in each eye was markedly improved and the diplopia resolved. There was an associated normalization of thiamine and copper, but folate levels remained low. We believe that the nutritional deficiency caused a bilateral optic neuropathy and the resulting vision loss precipitated a manifestation of a congenital superior oblique palsy that had previously just been a phoria. The case emphasizes the importance of considering occult sensory etiologies of acquired strabismus.

A Clinical Case of Two-Stage Visual-Functional Rehabilitation of a Patient with Postinfectious Central Corneal Opacity in Combination with Mixed Astigmatism Using Laser Keratorefractive Surgery

Introduction: to evaluate the clinical and functional results of two-stage treatment in a patient with post-infectious Central corneal opacity combined with mixed astigmatism.Patient and methods. Patient N., 19 years old with postinfectious (postherpetic) Central corneal opacity, mixed astigmatism was examined and operated using two-stage corneal laser treatment. To determine the possibility of surgical treatment of the patient, a complex of General ophthalmology was performed (checking visual acuity near and far in natural conditions and in conditions of drug-induced mydriasis, IOP measurement, autorefractometry, examination of visual fields, A- and Bscanning, ophthalmoscopy with examination of the Central and peripheral areas of the fundus), as well as special (keratopography and Scheimpflug camera examination, optical coherence tomography (OCT) of the anterior segment of the eye with analysis of the epithelial map, quantitative assessment (Schirmer test-1) and qualitative (tear film rupture time) lachrymal products, assessment of the epithelium state when stained with vital dyes and infrared meibography) research methods. To determine the activity of herpetic infection, PCR diagnostics were performed. The follow-up period was 2 years.Results and discussion. To achieve high visual-functional rehabilitation while preserving the native lens, a two-stage treatment algorithm was developed using technologies of laser corneal refractive surgery. At the first stage, in order to regularize the ocular surface and eliminate Central corneal opacity, an inverted topographically oriented PRK was performed; at the second stage, residual refractive errors were corrected using topographically oriented FemtoLASIK technology.Conclusion. According to the results of a literature search and analysis of Internet resources, there were no previously recorded and published works using a similar two-stage method. Therefore, the described clinical case justifies the relevance and novelty of the goal and has an evidence-based Foundation for the use of a two-stage laser keratorefractive treatment system in the ophthalmological practice of visual and functional rehabilitation of patients with Central corneal opacity in combination with mixed astigmatism or hypermetropic refraction. The two-year postoperative follow-up period showed stable and high visual-functional results with no recurrence of the inflammatory process.

Leveraging Visual Outcome Measures to Advance Therapy Development in Neuroimmunologic Disorders

The visual system offers unparalleled precision in the assessment of neuroaxonal damage. With the majority of patients with multiple sclerosis (MS) experiencing afferent and efferent visual dysfunction, outcome measures capturing these deficits provide insight into neuroaxonal injury, even in those with minimal disability. Ideal for use in clinical trials, visual measures are generally inexpensive, accessible, and reproducible. Quantification of visual acuity, visual fields, visual quality of life, and electrophysiologic parameters allows assessment of function, whereas optical coherence tomography (OCT) provides reliable measures of the structural integrity of the anterior afferent visual pathway. The technology of oculomotor biometrics continues to advance, and discrete measures of fixation, smooth pursuit, and saccadic eye movement abnormalities are ready for inclusion in future trials of MS progression. Visual outcomes allow tracking of neuroaxonal injury and aid in distinguishing MS from diseases such as neuromyelitis optica spectrum disorder (NMOSD) or myelin oligodendrocyte glycoprotein antibody–associated diseases (MOGAD). OCT has also provided unique insights into pathophysiology, including the identification of foveal pitting in NMOSD, possibly from damage to Müller cells, which carry an abundance of aquaporin-4 channels. For some study designs, the cost-benefit ratio favors visual outcomes over more expensive MRI outcomes. With the next frontier of therapeutics focused on remyelination and neuroprotection, visual outcomes are likely to take center stage. As an international community of collaborative, committed, vision scientists, this review by the International MS Visual System Consortium (IMSVISUAL) outlines the quality standards, informatics, and framework needed to routinely incorporate vision outcomes into MS and NMOSD trials.

Rasio Penutupan Luka pada Tikus Diabetes Diinduksi Streptozotocin dengan Perlakuan Dressing Tipe Pasif dan Interaktif (Penelitian Pendahuluan)

Deparaffinization is a stage before the staining process to remove/dissolve paraffin so that the absorption of color in tissue preparations is maximized. Deparaffinization is usually carried out using xylol and toluol. Xylol has toxic effects including acute neurotoxicity, heart and kidney damage, hepatotoxicity, fatal blood dyscrasias, skin erythema, dry skin, peeling skin, and also has a carcinogenic effect. The toxicity effect of olive oil is lower than that of xylol. Oils that have non-polar properties can remove the remaining paraffin contained in the tissue. The purpose of this study was to determine the microscopic appearance of the kidney tissue preparations of mice deparaffinized with olive oil on hematoxylin eosin (HE) staining. The type of research used is experimental research which is analyzed with a descriptive approach. The results of the assessment of preparations deparaffinized with xylol in 80 visual fields obtained 100% good preparations and preparations deparaffinized with olive oil in 80 visual fields obtained 0% poor preparations, 11.3% poor preparations, and 88.7% good preparation. So it can be said that better results are found in the microscopic picture of the kidney preparations of mice (Mus musculus) deparaffinized with xylol.

Visual field differences in temporal synchrony processing for audio-visual stimuli

Audio-visual integration relies on temporal synchrony between visual and auditory inputs. However, differences in traveling and transmitting speeds between visual and auditory stimuli exist; therefore, audio-visual synchrony perception exhibits flexible functions. The processing speed of visual stimuli affects the perception of audio-visual synchrony. The present study examined the effects of visual fields, in which visual stimuli are presented, for the processing of audio-visual temporal synchrony. The point of subjective simultaneity, the temporal binding window, and the rapid recalibration effect were measured using temporal order judgment, simultaneity judgment, and stream/bounce perception, because different mechanisms of temporal processing have been suggested among these three paradigms. The results indicate that auditory stimuli should be presented earlier for visual stimuli in the central visual field than in the peripheral visual field condition in order to perceive subjective simultaneity in the temporal order judgment task conducted in this study. Meanwhile, the subjective simultaneity bandwidth was broader in the central visual field than in the peripheral visual field during the simultaneity judgment task. In the stream/bounce perception task, neither the point of subjective simultaneity nor the temporal binding window differed between the two types of visual fields. Moreover, rapid recalibration occurred in both visual fields during the simultaneity judgment tasks. However, during the temporal order judgment task and stream/bounce perception, rapid recalibration occurred only in the central visual field. These results suggest that differences in visual processing speed based on the visual field modulate the temporal processing of audio-visual stimuli. Furthermore, these three tasks, temporal order judgment, simultaneity judgment, and stream/bounce perception, each have distinct functional characteristics for audio-visual synchrony perception. Future studies are necessary to confirm the effects of compensation regarding differences in the temporal resolution of the visual field in later cortical visual pathways on visual field differences in audio-visual temporal synchrony.