Implantable Imaging System for Visual Prosthesis

In order to propose a method of intraocular imaging system for the visual prosthesis, an implantable microcamera was developed and evaluated in vivo. The microcamera was specially developed and shaped to fit the rabbit's lens capsule and encapsulated with the biocompatible silicone. To evaluate the feasibility of this novel approach, the custom‐built device was implanted following the surgical extraction of rabbit's lens. And clinical examinations were performed 1 day, 3 days, 1 week, 2 week, and 1 month postoperatively, including slit‐lamp examination, intraocular pressure, wound status, anterior chamber depth, the presence of the iris fibrosi of neovascularization, and the position of the implant. Real‐time imaging was performed in vivo 1 month after the operation, and the acquired images were processed with the software and hardware that were specially developed for generating the stimulating pulses. Short‐term results showed the novel approach is promising.     

Visual field deficit due to downward displacement of optic chiasm

Visual disturbance in hydrocephalus is typically due to raised intracranial pressure. We describe a patient who presented with marked loss of peripheral visual fields, but without features suggestive of raised intracranial pressure. MR scan showed an enlarged third ventricle and a downward displacement of the optic chiasm, Chiari II malformation. These radiological changes and the visual field deficits reversed after endoscopic third ventriculostomy and foramen magnum decompression. These observations support the view that the treatment of the hydrocephalus in such patients can help to reverse the change in the position of the optic chiasm and the visual field deficits.     

Visual outcome and ocular survival in open-globe injuries

AIM: To detect the risk factors that predicts final visual acuity, retinal detachment, and ocular survival after penetrating trauma. METHODS: In a prospective case series study, 116 eyes with open-globe injuries were evaluated between 2001 and 2004. All data were filled in the questionnaire chart. Sex, age, involved eye, best-corrected visual acuity (BCVA), afferent pupillary defect (APD), location and wound length, cataract, iris prolapse, vitreous prolapse, retinal detachment (RD), intraocular foreign body (IOFB), vitrectomy procedure, and type of injury were evaluated as predisposing factors by logistic regression models for final visual acuity, RD, and ocular survival. RESULTS: Low BCVA, RD, and vitrectomy procedure were detected significant in the final visual acuity of 20/200 or less. APD and vitrectomy procedure were statistically significant in the final RD. BCVA 20/250 or less, wound length >10mm, scleral and corneoscleral lacerations, vitreous prolapse, vitreous hemorrhage, RD, and sharp injury were correlated with decreased globe survival. CONCLUSION: Low BCVA, APD, and vitrectomy procedure were effective in the visual outcome. RD and vitrectomy procedure were detected significant in the anatomic result. Establishment of predictors of visual outcome and ocular survival may assist clinicians in salvageable eyes for surgical repair.     

Visual recovery following optic nerve decompression for chronic compressive neuropathy

Purpose  Visual failure due to optic nerve compression is a common indication for decompressive surgery. Most data only refer to the odds of improvement, deterioration or remaining the same. However, patients frequently wish to know more detail about the outcomes of surgery. Our aim was to assess the visual outcome from optic nerve decompression for visual failure in detail in order to help counsel patients pre-operatively. Methods  Sixty-eight patients undergoing 71 operations to decompress 87 optic nerves between 1991 and 2007 were identified. Thirty-four decompressions were performed via a transzygomatic and 37 via a transbasal approach. Fifty-two patients had meningiomas, 3 pituitary adenomas, 3 craniopharyngiomas, 3 chordomas, 2 adenocarcinomas, 2 fibrous dysplasia, 1 schwannoma, 1 granular pituitary tumour and 1 olfactory neuroblastoma. Visual acuity and fields were recorded pre-operatively, immediately post-operatively, at first follow-up and at most recent follow-up. Results  Forty-three eyes (49.4%) experienced an improvement in either acuity or fields. Twenty-four (27.5%) were unchanged and 20 (22.9%) deteriorated. Average improvement was 0.88 Snellen lines (logMAR 0.13). Improvement was seen between immediate post-operative acuity and first follow-up in 52%, but 22% suffered a late deterioration after 1 year. There was no relationship between age, duration of symptoms, pathology, approach or redo surgery and visual outcome. There was a complex relationship between pre-operative visual acuity and post-operative improvement and outcome. Better pre-operative acuity predicted better outcome and greater odds of improvement, although patients with poor pre-operative vision had a greater average magnitude of improvement. Conclusions  Patients experience significant benefit from optic nerve decompression irrespective of pre-operative visual status. Although early decompression is desirable, good results can still be obtained in patients with severe visual failure. Detailed data on visual outcome can help counsel patients pre-operatively to aid decision-making and set expectations.     

Visual spatial perception and surgical competence

BACKGROUND: Proficiency in visual spatial perception (VSP) is a hypothetical component of surgical competence. METHODS: Four tests of VSP, taken from the Cognitive Laterality Battery (CLB), were administered to 301 surgeons and surgical residents. Mean scores on each test were compared by Student t tests to those of the normative sample (n = 251) on which the test was originally standardized. RESULTS: Mean scores on two of the tests (Orientation, Touching Blocks) were significantly greater (P <0.01) for the study sample than for the normative sample, while mean scores on the other two subtests (Form Completion, Localization) were not. CONCLUSIONS: Surgeons tend to outperform the general population on tests of high-level VSP abilities (ie, envisioning depth and mentally manipulating two-dimensional representations of three-dimensional structures) identified previously as correlates of surgical skill acquisition. VSP proficiency is a valid component of surgical competence that should perhaps be included in career selection discussions with medical students and in assessment of the competence of surgeons.     

Phosphene Object Perception Employs Holistic Processing During Early Visual Processing Stage

Psychophysical studies have verified the possibility of recovering the visual ability by the form of low‐resolution format of images, that is, phosphene‐based representations. Our previous study has found that early visual processing for phosphene patterns is configuration based. This study further investigated the configural processing mechanisms of prosthetic vision by analyzing the event‐related potential components (P1 and N170) in response to phosphene face and non‐face stimuli. The results reveal that the coarse processing of phosphenes involves phosphene‐specific holistic processing that recovers separated phosphenes into a gestalt; low‐level feature processing of phosphenes is also enhanced compared with that of normal stimuli due to increased contrast borders introduced by phosphenes; while fine processing of phosphene stimuli is impaired reflected by reduced N170 amplitude because of the degraded detailed features in the low‐resolution format representations. Therefore, we suggest that strategies that can facilitate the specific holistic processing stages of prosthetic vision should be considered in order to improve the performance when designing the visual prosthesis system.     

Evaluating postherniorrhaphy groin pain: Visual Analogue or Verbal Rating Scale?

Introduction Several tools for pain measurement including a Visual Analogue Scale (VAS) and a Verbal Rating Scale (VRS) are currently used in patients with chronic pain. The aim of the present study was to determine which of these two pain tests performs optimally in patients following groin hernia repair. Patients and methods A questionnaire identified pain level in a cohort of patients that had previously undergone corrective groin hernia surgery. Current pain intensity was graded on a four-point VRS scale (no pain, mild, moderate or severe pain) and on a 100-mm VAS scale (0 = no pain, 100 = unbearable). “Scale failure” (one or both tests not completed correctly) was determined, and cut-off points for the VAS test were calculated by creating the optimum kappa coefficient between both tools. Results The response rate was 78.2% (706/903). Scale failure was present in VAS tests more than VRS (VAS: 12.5%, 88/706 vs. VRS: 2.8%, 20/706; P < 0.001). Advanced age was a risk factor for scale failure (P < 0.001). The four categories of VRS corresponded to mean VAS scores of 1, 20, 42, and 78 mm, respectively. VAS categories associated with the highest kappa coefficient (k = 0.78) were as follows: 0–8 = no pain, 9–32 = mild, 33–71 = moderate, >71 = severe pain. VAS scores grouped per VRS category showed considerable overlap. Age and sex did not significantly influence cut-off points. Conclusions Because of lower scale failure rates and overlapping VAS scores per VRS category, the VRS should be favored over the VAS in future postherniorrhaphy pain assessment. If VAS is preferred, the presented cut-off points should be utilized. This study was unfunded.     

Simplification of Visual Rendering in Simulated Prosthetic Vision Facilitates Navigation

Visual neuroprostheses are still limited and simulated prosthetic vision (SPV) is used to evaluate potential and forthcoming functionality of these implants. SPV has been used to evaluate the minimum requirement on visual neuroprosthetic characteristics to restore various functions such as reading, objects and face recognition, object grasping, etc. Some of these studies focused on obstacle avoidance but only a few investigated orientation or navigation abilities with prosthetic vision. The resolution of current arrays of electrodes is not sufficient to allow navigation tasks without additional processing of the visual input. In this study, we simulated a low resolution array (15 × 18 electrodes, similar to a forthcoming generation of arrays) and evaluated the navigation abilities restored when visual information was processed with various computer vision algorithms to enhance the visual rendering. Three main visual rendering strategies were compared to a control rendering in a wayfinding task within an unknown environment. The control rendering corresponded to a resizing of the original image onto the electrode array size, according to the average brightness of the pixels. In the first rendering strategy, vision distance was limited to 3, 6, or 9 m, respectively. In the second strategy, the rendering was not based on the brightness of the image pixels, but on the distance between the user and the elements in the field of view. In the last rendering strategy, only the edges of the environments were displayed, similar to a wireframe rendering. All the tested renderings, except the 3 m limitation of the viewing distance, improved navigation performance and decreased cognitive load. Interestingly, the distance‐based and wireframe renderings also improved the cognitive mapping of the unknown environment. These results show that low resolution implants are usable for wayfinding if specific computer vision algorithms are used to select and display appropriate information regarding the environment.     

基于CNKI和Web of Science核心合集数据库的人工智能脊柱领域可视化分析

目的：利用CiteSpace软件对国内外人工智能脊柱领域研究进行可视化分析并创建知识图谱,通过分析人工智能脊柱领域在国内外的发展,对比国内外人工智能脊柱领域的研究热点,为相关研究提供参考。方法：中文数据检索以最新版本中国知网（CNKI）数据库,使用“人工智能”和“脊柱”为主题词进行高级检索;英文文献数据检索以Web of Science核心合集为数据来源,检索式为“TI=(Artificial Intelligence*)And TI=(Spine*)”,从检索结果中排除会议、报纸、重复等不符合研究对象的文献,最终得到人工智能脊柱领域的57篇中文文献和124篇英文文献,导入CiteSpace信息可视化软件进行统计分析,对文献进行热点分析、国家机构分析、文献计量学可视化分析。结果：人工智能脊柱领域发文最多的国家是美国,中国位列第三名。我国人工智能脊柱领域出现频率最多的关键词是机器人、人工智能、深度学习。国际出现次数最多的关键词是classification、diagnosis、model。我国在人工智能脊柱领域发表中文文献最多的机构是海军军医大学第二附属医院,国外发表人工智能脊柱领域文献...     

Using Visual Trepan to Treat Single Segment Ossification of the Ligamentum Flavum Under Endoscopy

This article describes the trepan technique for treating single segment ossification of the ligamentum flavum (OLF) using an endoscope. OLF is the most common cause of thoracic spinal stenosis. The most common surgical procedures involve semi‐lamina or full‐lamina resection and decompression. However, considering the anatomical structure of the thoracic spinal canal and the combination of OLF, traditional surgery has higher risks, more complications, and greater technical requirements. In the past ten years, with the development of endoscopic technology, spinal endoscopy has been increasingly applied for the treatment of intervertebral disc herniation and spinal canal stenosis. The present study demonstrated the effectiveness of visual trepan decompression under spinal endoscopy used for patients with single segment OLF. This surgical procedure had many advantages, including a shorter operation time, minimal trauma, less expenditure, and better functional recovery over the conventional open surgery.     

基于 CiteSpace 可视化分析中医药治疗特应性皮炎的研究热点

目的 对中医药治疗特应性皮炎的相关文献进行计量与可视化分析,探讨其研究热点和发展趋 势,为其治疗提供一定参考。方法 以中国知网数据库（CNKI）为数据源检索2010年6月-2022年6月中医 药治疗特应性皮炎相关文献,利用CiteSpace 6.1.R2软件对关键词进行共现分析、聚类分析和突现分析,并 绘制相关图谱。结果 共纳入文献361篇,涉及的关键词有中药、儿童、龙牡汤、临床观察、辨证论治、临 床研究、针刺、生活质量、中医药、中医证型、中药药浴、中医。热点关键词为儿童、辨证论治、生活质 量、龙牡汤。聚类分析所产生的主要聚类有儿童、血虚风燥、龙牡汤、辨证分型、心火、生活质量等。突 现强度位于前3位的关键词为龙牡汤、针刺、中医药,其次分别为用药规律、辨证论治、中药、湿疮、血 虚风燥、健脾化湿等。结论 中医药治疗特应性皮炎的研究热点集中在儿童、血虚风燥、龙牡汤、辨证分 型、心火、生活质量等方面。     

Image Processing Strategies Based on a Visual Saliency Model for Object Recognition Under Simulated Prosthetic Vision

Retinal prostheses have the potential to restore partial vision. Object recognition in scenes of daily life is one of the essential tasks for implant wearers. Still limited by the low‐resolution visual percepts provided by retinal prostheses, it is important to investigate and apply image processing methods to convey more useful visual information to the wearers. We proposed two image processing strategies based on Itti's visual saliency map, region of interest (ROI) extraction, and image segmentation. Itti's saliency model generated a saliency map from the original image, in which salient regions were grouped into ROI by the fuzzy c‐means clustering. Then Grabcut generated a proto‐object from the ROI labeled image which was recombined with background and enhanced in two ways—8‐4 separated pixelization (8‐4 SP) and background edge extraction (BEE). Results showed that both 8‐4 SP and BEE had significantly higher recognition accuracy in comparison with direct pixelization (DP). Each saliency‐based image processing strategy was subject to the performance of image segmentation. Under good and perfect segmentation conditions, BEE and 8‐4 SP obtained noticeably higher recognition accuracy than DP, and under bad segmentation condition, only BEE boosted the performance. The application of saliency‐based image processing strategies was verified to be beneficial to object recognition in daily scenes under simulated prosthetic vision. They are hoped to help the development of the image processing module for future retinal prostheses, and thus provide more benefit for the patients.     

Oswestry Disability Index is a better indicator of lumbar motion than the Visual Analogue Scale

Background contextLumbar pathology is often associated with axial pain or neurologic complaints. It is often presumed that such pain is associated with decreased lumbar motion; however, this correlation is not well established. The utility of various outcome measures that are used in both research and clinical practice have been studied, but the connection with range of motion (ROM) has not been well documented.PurposeThe current study was performed to assess objectively the postulated correlation of lumbar complaints (based on standardized outcome measures) with extremes of lumbar ROM and functional ROM (fROM) with activities of daily living (ADLs) as assessed with an electrogoniometer.Study design/settingThis study was a clinical cohort study.Patient sampleSubjects slated to undergo a lumbar intervention (injection, decompression, and/or fusion) were enrolled voluntarily in the study.Outcome measuresThe two outcome measures used in the study were the Visual Analogue Scale (VAS) for axial extremity, lower extremity, and combined axial and lower extremity, as well as the Oswestry Disability Index (ODI).MethodsPain and disability scores were assessed with the VAS score and ODI. A previously validated electrogoniometer was used to measure ROM (extremes of motion in three planes) and fROM (functional motion during 15 simulated activities of daily living). Pain and disability scores were analyzed for statistically significant association with the motion assessments using linear regression analyses.ResultsTwenty-eight men and 39 women were enrolled, with an average age of 55.6 years (range, 18–79 years). The ODI and VAS were associated positively (p<.001). Combined axial and lower extremity VAS scores were associated with lateral and rotational ROM (p<.05), but not with flexion/extension or any fROM. Similar findings were noted for separately analyzed axial and lower extremity VAS scores. On the other hand, the ODI correlated inversely with ROM in all planes, and fROM in at least one plane for 10 of 15 ADLs (p<.05).ConclusionsExtremes of lumbar motion and motions associated with ADLs are of increasing clinical interest. Although the ODI and VAS are associated with each other, the ODI appears to be a better predictor of these motion parameters than the VAS (axial extremity, lower extremity, or combined) and may be more useful in the clinical setting when considering functional movement parameters.     

Normative data of the Visual Analogue Scale Foot and Ankle (VAS FA) for pathological conditions

Background

The purpose of this study was to analyze the Visual Analogue Scale Foot and Ankle (VAS FA) in patients to obtain normative data for pathological conditions.

Methods

The VAS FA was consecutively obtained in a foot and ankle outpatient clinic. The score results were categorized into different pathological foot and ankle conditions.

Results

414 patients were evaluated. Overall scores and score categories of all pathology groups differed from non-pathological data (n = 121). Within the different groups, no score differences occurred. Score standards were defined for these groups with sufficient statistical power (>.8): isolated Hallux valgus, Hallux valgus and claw toes, forefoot other pathology, midfoot other pathology, hindfoot pathology and ankle deformity. No standards were defined for other pathology groups.

Conclusions

The obtained data is normative for different pathological conditions of the earlier validated VAS FA. The obtained data is normative for different pathological conditions of the earlier validated VAS FA. This data could serve as a basis for assessment patient scoring before, during and after treatment which has to then to be proved by ongoing research.     

Use and ease of self-administered International Prostate Symptoms Score (IPSS) and Visual Prostate Symptoms Score (VPSS) questionnaires for the assessment of lower urinary tract symptoms in Nigerian men

ObjectivesTo evaluate the use of the Visual Prostate Symptoms Score (VPSS) and International Prostate Symptoms Score (IPSS) questionnaires for the assessment of lower urinary tract symptoms (LUTS) in Nigerian men, with special emphasis on the ease of administration and the time needed to complete the questionnaires.Patients and methodsThis cross-sectional survey of men with LUTS was carried out at a tertiary-care hospital in Nigeria between July and December, 2014. The symptoms were assessed using the IPSS and VPSS questionnaires. A structured questionnaire was created to collect data on socio-demographics, literacy, visual impairment and the time needed to complete the IPSS and VPSS questionnaires. The data were collated, and Pearson's chi-square test was performed using a contingency table. Spearman's rank correlation test was done for IPSS and VPSS, while the paired t-test was used for the average time spent in completing both questionnaires. A p-value <0.05 was considered as significant.ResultsNinety patients aged between 56 and 80 years were enrolled in the study. Thirty-one (34.4%) were literate in English, while 59 (65.6%) were illiterate. The literate patients with at least secondary education completed the IPSS questionnaire without assistance. The VPSS questionnaire was completed without assistance by 43 (72.9%) illiterate patients, while all the patients with visual impairment needed assistance to complete it. There was a statistically significant correlation between the IPSS and VPSS. Completion of the VPSS questionnaire required half of the time needed to complete the IPSS questionnaire.ConclusionTo complete the IPSS questionnaire, Nigerian men require a literacy status of at least secondary education. VPSS correlated significantly with IPSS. Both questionnaires can be used to assess LUTS in uneducated patients and those with a low educational level, but visual impairment may preclude their use. It takes less time to complete the VPSS compared to the IPSS questionnaire.     

Visual hallucinations

Opinion statement Neurologists and ophthalmologists should be familiar with the causes and treatment of visual hallucinations so that they are able to reassure patients and minimize the anguish associated with untreated visual hallucinations. Hallucinations are underreported by patients because of the perceived psychiatric implication or because of poor insight into the unreal nature of the hallucinations. In the appropriate setting, physicians should specifically inquire about hallucinations as well as initiate medical treatment. Visual hallucinations have many etiologies and are associated with a variety of disorders. Identification of the associated disorder or cause is necessary to determine the appropriate treatment. Causes and associated disorders include ocular phenomena, migraine, seizures, visual loss (ie, release hallucinations), neurodegenerative disorders, midbrain injury, alcohol and drug effects, narcolepsy, post-traumatic stress disorder, and psychosis. Therapeutic treatment should be directed at the associated disorder or etiology. For instance, antiepileptic drugs may be appropriate for patients with irritative phenomena such as seizures and visual aura of migraine. Depending on the cause, other agents are available and include neuroleptics, cholinesterase inhibitors, and acetazolamide. Well-designed, randomized, controlled clinical trials regarding treatment of visual hallucinations associated with various disorders are lacking. Although complete resolution of visual hallucinations can be difficult, even minimal improvement may be symptomatically beneficial.