Visualisation ergonomics and robotic surgery.

Stereopsis may be an advantage of robotic surgery. Perceived robotic ergonomic advantages in visualisation include better exposure, three-dimensional vision, surgeon camera control, and line of sight screen location. Other ergonomic factors relating to visualisation include stereo-acuity, vergence-accommodation mismatch, visual-perception mismatch, visual-vestibular mismatch, visuospatial ability, visual fatigue, and visual feedback to compensate for lack of haptic feedback. Visual fatigue symptoms may be related to dry eye or accommodative/binocular vision stress. Digital eye strain can be measured by questionnaires and objective tests. Management options include treatment of dry eye, correction of refractive error, and management of accommodation and vergence anomalies. Experienced robotic surgeons can use visual cues like tissue deformation and surgical tool information as surrogates for haptic feedback.

Prevalence and determinants of asthenopia among ophthalmologists in China: a national cross-sectional survey.

Introduction: The role of ophthalmologists is defined by tasks requiring visual effort, emphasizing the importance of examining their condition within the realm of occupational visual health. Our goal was to explore the occurrence of asthenopia among Chinese ophthalmologists and identify contributing factors through the use of a reliable and validated survey instrument. Methods: A national cross-sectional online survey was carried out in June 2017, involving 6,220 practicing ophthalmologists in China. Utilizing an 11-item Asthenopia Survey Questionnaire with established reliability and validity. Prevalence rates of asthenopia among subgroups categorized by age, gender, hospital classification, physician level, daily near vision activity duration, sleep duration, sleep quality, presbyopia status, and history of eye surgery were determined using the independent t-test, chi-square test and bonferroni test. Multiple logistic regression analysis was employed to pinpoint independent factors linked to asthenopia. Results: Out of the 5,009 ophthalmologists who completed the survey, a 40.7% prevalence of asthenopia was identified. Multivariate analysis revealed that good sleep quality (OR: 0.24, 95%CI: 0.20-0.30), moderate sleep quality (OR: 0.47, 95%CI: 0.38-0.59), engaging in daily near vision activities for less than 7 h (OR: 0.76, 95%CI: 0.68-0.86), having daily sleep duration exceeding 7 h (OR: 0.87, 95%CI: 0.77-0.98), and working in tertiary hospitals (OR: 0.88, 95%CI: 0.78-0.99) were protective factors against asthenopia. Conversely, presbyopia was identified as a risk factor (OR: 1.33, 95%CI: 1.04-1.70). All calculated p values were below 0.05. Age, gender, physician level, and eye surgery history were not related factors. Conclusion: Asthenopia is prevalent among Chinese ophthalmologists, with employment in tertiary hospitals providing a protective effect and presbyopia is a risk factor. Preventive strategies include improving sleep quality, restricting daily near vision activity to under 7 h, and extending daily sleep duration to over 7 h. Further investigation is needed to explore the protective implications of working in tertiary hospitals.

Digital asthenopia: blue-blocking lenses and + 0,40D additional power in the near zone, for eye strain, accommodation and convergence functions / Astenopia digital: avaliação de lentes com filtro de luz azul e poder adicional de +0,40D na zona de perto, para fadiga visual e nas funções de convergência e acomodação

ABSTRACT Purpose Evaluate blue-violet light filter and additional power of +0.40 D in the near zone ophthalmic lenses, on convergence, accommodative functions, and symptoms of digital asthenopia (DA). Methods Randomized study in cross-over design conducted on 49 volunteers (age, 29 ± 5.5 years; male: female, 18:31). Each subject wore test (+0.40 D in the near zone) and control lenses (regular single vision) for 4 weeks in randomized order. Both lenses had a selective blue-violet light filter. A baseline measurement was taken with the subjects' current updated glasses. Accommodation amplitude (AA) and near point of convergence (NPC) were measured binocularly with the RAF ruler. DA was evaluated by a questionnaire. Results No significant difference (p=.52) was found for AA comparing baseline (11.50±1.88 D), test (11.61± 1.62 D), and control SV lenses (11.88±1.50 D). No significant difference was found for NPC (p=.94), between baseline (6.50 ± 2.89cm), test (6.71± 3.49) and control SV lenses (6.82± 3.50 cm). No significant difference was found comparing test and control SV lenses in symptoms of DA (p=0.20). Conclusions The +0.40 D lenses have no negative impact on convergence or loss of accommodation power. The +0.40 D and control SV lenses had a similar impact on attenuating symptoms of DA.

RESUMO Objetivo Avaliar os efeitos do uso de lentes oftálmicas com filtro seletivo de luz azul-violeta, sem e com poder adicional de + 0,4D na zona de perto nas funções de acomodação e convergência e para sintomas de astenopia digital (AD). Métodos Ensaio clínico controlado, randomizado e mascarado, com 49 voluntários (idade, 29 ± 5,5 anos; masculino: feminino, 18: 31). Cada participante usou lentes de teste (+0,40 D na zona de perto) e controle (visão simples), por 4 semanas de forma randomizada. Ambas as lentes tinham filtro seletivo de luz azul-violeta. A medição inicial (baseline) foi feita com os óculos atualizados de cada participante. A amplitude de acomodação (AA) e o ponto de convergência próximo (PPC) foram medidos binocularmente com a régua RAF. A AD foi avaliada por um questionário. Resultados Não houve diferença estatisticamente significante (p=0,52) para as medidas de AA comparando as lentes baseline (11,50±1,88 D), teste (11,61±1,62 D) e controle VS (11,88±1,50 D). Nenhuma diferença significativa foi encontrada para a medida do PPC (p=0,94), entre as lentes baseline (6,50 ± 2,89cm), teste (6,71±3,49) e controle VS (6,82±3,50 cm). Nenhuma diferença significativa foi encontrada comparando lentes teste de VS e controle nos sintomas de AD (p=0,20). Conclusões As lentes com +0,40 D não têm impacto negativo na convergência ou na perda de acomodação. As lentes +0,40 D e controle VS, tiveram impacto semelhante na redução dos sintomas de AD.

Applicability and Effectiveness of Laparoscopic Procedures in Pediatrics.

Background: Three-dimensional (3D) laparoscopic surgery in pediatrics is still uncommon and few studies assessed in clinical practice advantages and disadvantages. Applicability and effectiveness of 3D versus two-dimensional (2D) laparoscopic procedures in congenital and acquired conditions in children are still unknown. We assessed applicability and effectiveness of 3D compared with 2D laparoscopic procedures in a pediatric setting. Methods: Two groups of patients who underwent 3D or 2D laparoscopic surgical procedures between May 2016 and April 2018 were compared. Each 3D/2D laparoscopic procedure was assessed with a surgeon/assistant questionnaire. Results: The 3D group included 30 patients and the 2D group 32 patients. The analysis of the 3D/2D questionnaire showed statistically significant superiority of 3D technical aspects (P = .0000), allowing a better spatial orientation and depth perception, reducing manipulation and trauma to tissues. Moreover, no difference was reported in physical complaints (P = .7084), but decreased visual fatigue was highlighted by surgeon (P = .000). Conclusions: In pediatric patients, 3D laparoscopic procedures prove to be more effective facilitating the surgeon's performance, while maintaining the benefits of minimally invasive surgery.

See-Through Type 3D Head-Mounted Display-Based Surgical Microscope System for Microsurgery: A Feasibility Study.

BACKGROUND: The surgical microscope is used primarily for microsurgeries, which are more complicated than other surgical procedures and require delicate tasks for a long time. Therefore, during these surgical procedures, surgeons experience back and neck pain. To solve this problem, new technology, such as wearable displays, is required to help surgeons maintain comfortable postures and enjoy advanced functionality during microsurgery. OBJECTIVE: The objective of this study was to develop a surgical microscope system that would work with wearable devices. It would include a head-mounted display (HMD) that can offer 3D surgical images and allow a flexible and comfortable posture instead of fixed eyepieces of surgical microscope and can also provide peripheral visual field with its optical see-through function. METHODS: We designed and fabricated a surgical microscope system that incorporates a see-through type 3D HMD, and we developed an image processing software to provide better image quality. The usability of the proposed system was confirmed with preclinical examination. Seven ENT (ear, nose, and throat) surgical specialists and 8 residents performed a mock surgery-axillary lymph node dissection on a rat. They alternated between looking through the eyepieces of the surgical microscope and viewing a 3D HMD screen connected to the surgical microscope. We examined the success of the surgery and asked the specialists and residents to grade eye fatigue on a scale of 0 (none) to 6 (severe) and posture discomfort on a scale of 1 (none) to 5 (severe). Furthermore, a statistical comparison was performed using 2-tailed paired t test, and P=.00083 was considered significant. RESULTS: Although 3D HMD case showed a slightly better result regarding visual discomfort (P=.097), the average eye fatigue was not significantly different between eyepiece and 3D HMD cases (P=.79). However, the average posture discomfort, especially in neck and shoulder, was lower with 3D HMD display use than with eyepiece use (P=.00083). CONCLUSIONS: We developed a see-through type 3D HMD-based surgical microscope system and showed through preclinical testing that the system could help reduce posture discomfort. The proposed system, with its advanced functions, could be a promising new technique for microsurgery.

Articulated Instruments and 3D Visualization: A Synergy? Evaluation of Execution Time, Errors, and Visual Fatigue.

Objective. The introduction of advanced endoscopic systems, such as the Storz Image1S and the Olympus Endoeye, heralds a new era of 3-dimensional (3D) visualization. The aim of this report is to provide a comprehensive overview of the neurophysiology of 3D view, its relevance in videoscopy, and to quantify the benefit of the new 3D technologies for both rigid and articulated instruments. Method. Sixteen medical students without any laparoscopic experience were trained each for a total of 27 hours. Proficiency scores were determined for rigid and articulated instruments under 2D and 3D visualization conditions. Results. A reduction in execution time of 14%, 28%, and 36% was seen for the rigid instruments, the da Vinci, and Steerable instruments, respectively. A reduction in errors of 84%, 92%, and 87% was seen for the rigid instruments, the da Vinci, and Steerable instruments, respectively. Conclusion. 3D visualization greatly augments endoscopic procedures. The advanced endoscopic systems employed in the recent study caused no visual fatigue or discomfort. The benefit of 3D was most distinct with articulated instruments.

Optical correction of refractive error for preventing and treating eye symptoms in computer users.

BACKGROUND: Computer users frequently complain about problems with seeing and functioning of the eyes. Asthenopia is a term generally used to describe symptoms related to (prolonged) use of the eyes like ocular fatigue, headache, pain or aching around the eyes, and burning and itchiness of the eyelids. The prevalence of asthenopia during or after work on a computer ranges from 46.3% to 68.5%. Uncorrected or under-corrected refractive error can contribute to the development of asthenopia. A refractive error is an error in the focusing of light by the eye and can lead to reduced visual acuity. There are various possibilities for optical correction of refractive errors including eyeglasses, contact lenses and refractive surgery. OBJECTIVES: To examine the evidence on the effectiveness, safety and applicability of optical correction of refractive error for reducing and preventing eye symptoms in computer users. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL); PubMed; Embase; Web of Science; and OSH update, all to 20 December 2017. Additionally, we searched trial registries and checked references of included studies. SELECTION CRITERIA: We included randomised controlled trials (RCTs) and quasi-randomised trials of interventions evaluating optical correction for computer workers with refractive error for preventing or treating asthenopia and their effect on health related quality of life. DATA COLLECTION AND ANALYSIS: Two authors independently assessed study eligibility and risk of bias, and extracted data. Where appropriate, we combined studies in a meta-analysis. MAIN RESULTS: We included eight studies with 381 participants. Three were parallel group RCTs, three were cross-over RCTs and two were quasi-randomised cross-over trials. All studies evaluated eyeglasses, there were no studies that evaluated contact lenses or surgery. Seven studies evaluated computer glasses with at least one focal area for the distance of the computer screen with or without additional focal areas in presbyopic persons. Six studies compared computer glasses to other types of glasses; and one study compared them to an ergonomic workplace assessment. The eighth study compared optimal correction of refractive error with the actual spectacle correction in use. Two studies evaluated computer glasses in persons with asthenopia but for the others the glasses were offered to all workers regardless of symptoms. The risk of bias was unclear in five, high in two and low in one study. Asthenopia was measured as eyestrain or a summary score of symptoms but there were no studies on health-related quality of life. Adverse events were measured as headache, nausea or dizziness. Median asthenopia scores at baseline were about 30% of the maximum possible score.Progressive computer glasses versus monofocal glassesOne study found no considerable difference in asthenopia between various progressive computer glasses and monofocal computer glasses after one-year follow-up (mean difference (MD) change scores 0.23, 95% confidence interval (CI) -5.0 to 5.4 on a 100 mm VAS scale, low quality evidence). For headache the results were in favour of progressive glasses.Progressive computer glasses with an intermediate focus in the upper part of the glasses versus other glassesIn two studies progressive computer glasses with intermediate focus led to a small decrease in asthenopia symptoms (SMD -0.49, 95% CI -0.75 to -0.23, low-quality evidence) but not in headache score in the short-term compared to general purpose progressive glasses. There were similar small decreases in dizziness. At medium term follow-up, in one study the effect size was not statistically significant (SMD -0.64, 95% CI -1.40 to 0.12). The study did not assess adverse events.Another study found no considerable difference in asthenopia between progressive computer glasses and monofocal computer glasses after one-year follow-up (MD change scores 1.44, 95% CI -6.95 to 9.83 on a 100 mm VAS scale, very low quality evidence). For headache the results were inconsistent.Progressive computer glasses with far-distance focus in the upper part of the glasses versus other glassesOne study found no considerable difference in number of persons with asthenopia between progressive computer glasses with far-distance focus and bifocal computer glasses after four weeks' follow-up (OR 1.00, 95% CI 0.40 to 2.50, very low quality evidence). The number of persons with headache, nausea and dizziness was also not different between groups.Another study found no considerable difference in asthenopia between progressive computer glasses with far-distance focus and monofocal computer glasses after one-year follow-up (MD change scores -1.79, 95% CI -11.60 to 8.02 on a 100 mm VAS scale, very low quality evidence). The effects on headaches were inconsistent.One study found no difference between progressive far-distance focus computer glasses and trifocal glasses in effect on eyestrain severity (MD -0.50, 95% CI -1.07 to 0.07, very low quality evidence) or on eyestrain frequency (MD -0.75, 95% CI -1.61 to 0.11, very low quality evidence).Progressive computer glasses versus ergonomic assessment with habitual (computer) glassesOne study found that computer glasses optimised for individual needs reduced asthenopia sum score more than an ergonomic assessment and habitual (computer) glasses (MD -8.9, 95% CI -16.47 to -1.33, scale 0 to 140, very low quality evidence) but there was no effect on the frequency of eyestrain (OR 1.08, 95% CI 0.38 to 3.11, very low quality evidence).We rated the quality of the evidence as low or very low due to risk of bias in the included studies, inconsistency in the results and imprecision. AUTHORS' CONCLUSIONS: There is low to very low quality evidence that providing computer users with progressive computer glasses does not lead to a considerable decrease in problems with the eyes or headaches compared to other computer glasses. Progressive computer glasses might be slightly better than progressive glasses for daily use in the short term but not in the intermediate term and there is no data on long-term follow-up. The quality of the evidence is low or very low and therefore we are uncertain about this conclusion. Larger studies with several hundreds of participants are needed with proper randomisation, validated outcome measurement methods, and longer follow-up of at least one year to improve the quality of the evidence.

Feasibility Study of the Three-Dimensional Flexible Endoscope in Endoscopic Submucosal Dissection: An ex vivo Animal Study.

BACKGROUND/AIM: Clinical application of 3-dimensional (3D) technology for flexible endoscopes has not been reported. We developed a 3D flexible endoscope and conducted a feasibility study of endoscopic submucosal dissection (ESD) in porcine stomach. METHODS: Four endoscopists used a 3D flexible endoscope to perform a total of 8 ESD procedures on resected porcine stomachs. We assessed the en bloc resection rate, perforation rate, and mechanical issues that arise during ESD. A visual analog scale (0, 2D superior; 100, 3D superior) was used to evaluate the depth perception, sense of security of the procedure, and eyestrain of 3D visualization. RESULTS: En bloc resection was achieved in all cases and there were no cases of perforation or mechanical issues. Depth perception and sense of security were rated 85.5 ± 12.4 and 70.7 ± 9.7 respectively (mean ± SDs). Eyestrain was rated high for 3D visualization (mean ± SDs, 12.6 ± 8.6). CONCLUSIONS: ESD using a 3D flexible endoscope was technically feasible. The endoscopists reported good depth perception and a high sense of security when using 3D visualization but also noted strong eyestrain.

Asthenopia in bankers: identification and analysis of risk factors / Astenopia em bancários: identificação e análise dos fatores de risco

Abstract Objective: To evaluate the prevalence of asthenopia in a cohort of bank employees and identify possible associated risk factors. Methods: Cross-sectional study based on information supplied by bankers in response to a standardized electronic questionnaire. Results: The questionnaire was responded by 945 bankers. The frequency of asthenopic symptoms was positively associated with female gender, age over 50 years, and reading or using the computer >6 hours a day. Conclusion: Asthenopic symptoms were found to be significantly associated with gender, age and time spent reading. The most frequently reported symptoms were headache and sore eyes.

Resumo Objetivo: Avaliar a presença de astenopia em bancários e identificar possíveis fatores de risco associados. Metodos: Estudo transversal realizado por meio de informações obtidas em um questionário padronizado, aplicado eletronicamente à trabalhadores da categoria de bancários. Resultados: Responderam ao questionário 945 trabalhadores. Observou-se que a frequência dos sintomas de astenopia foi maior nos grupos que declararam usar computador ou ler por mais de 6 horas por dia. As queixas de astenopia foram significativamente maiores nos trabalhadores com mais de 50 anos e do sexo feminino. Conclusão: Este trabalho identificou uma associação positiva de queixas de astenopia em bancários em relação ao tempo de leitura, sexo e idade. Dentre os sintomas oculares associados à astenopia, foi encontrada uma maior prevalência de dor de cabeça e dor nos olhos.

Lighting at computer workstations.

BACKGROUND: The visual conditions for computer work are complex and include several factors that need to be well controlled. These factors include the lighting system, the design of the computer and screen itself, the screens position and orientation within the room, the surface reflectances and colours of the room, and the visualability of the worker. OBJECTIVE: The objective was to review the literature (including standards) on lighting for computer work in an accessible summary. This contribution focuses on lighting for computer work, but the reader is reminded of the fact that lighting continuously interacts with the other factors mentioned above. RESULTS/CONCLUSION: The combined visual conditions shall enable the worker to see and perform the work task without causing unnecessary strain for the eyes or the other parts of the body. The main lighting-related factors in the visual environment to evaluate are: illuminance, luminance, direction of light, glare, correlated colour temperature of the light source (CCT), colour rendering of the light source, and the non-visual effects (such as non-visual flicker). A visual ergonomics checklist is presented as a guide to analyse the visual environment.

Effect of Blue Light-Reducing Eye Glasses on Critical Flicker Frequency.

PURPOSE: This study aims to evaluate the effect of blocking short-wavelength light on critical flicker frequency (CFF). DESIGN: This study is a prospective clinical study. METHODS: Thirty-three participants (17 men and 16 women; age range, 28-39 years) were divided into 3 groups. Each group wore 1 of 3 types of lenses while performing an intensive computer task for 2 hours. To evaluate the effect of blocking short-wavelength light before and after the task, we measured the CFF and evaluated subjective questionnaires. We used the analysis of variance test to examine whether the type of lenses tested affected any of the visual fatigue-related parameters. RESULTS: The type of lens worn significantly affected the CFF; however, answers to the subjective questionnaires did not differ significantly between the groups. Two of the 13 question items showed a statistical difference between lens transparency and increase in the CFF (lens 3 > lens 2 > lens 1). CONCLUSIONS: The higher the blocking effect of the lens, the lower the reduction in the CFF, suggesting that blocking short-wavelength light can reduce eye fatigue.

A Comparative Study of Distinct Ocular Symptoms After Performing Laparoscopic Surgical Tasks Using a Three-Dimensional Surgical Imaging System and a Conventional Two-Dimensional Surgical Imaging System.

BACKGROUND AND PURPOSE: Stereoscopic imaging systems have improved the surgical accuracy and patient safety but have induced unwanted visual disturbance, nausea, and ocular symptoms simultaneously. We measured and compared visual discomfort and visual fatigue induced by three-dimensional (3D) surgical imaging system and two-dimentional (2D) surgical imaging system, respectively. METHODS: This study compared ocular symptoms and visual functions immediately after four laparoscopic tasks including pick beans, paper cut, pass the curved needle, and knot tying. Ten participants started with 3D laparoscopy, 9 participants with 2D laparoscopy on the first day, and reversed the laparoscopy for the participants on the second day. Before performing the tasks and immediately after performing the tasks for 1 hour, the participants underwent an interview with questions on ocular symptoms, and then received the systematic measurements of the visual functions objectively. The ocular symptoms were compared between the two groups, and the visual functions were compared in each group and between the two groups. RESULTS: When comparing the 3D laparoscopy group with the 2D laparoscopy group, symptom scores showed statistically significant differences in blurred vision during the task (z=-3.64, P=0.00), irritated or burning eyes (z=-2.17, P=0.03), dry eyes (z=-2.72, P=0.01), eyestrain (z=-3.11, P=0.00), headache (z=-3.20, P=0.00), discomfort in eyes (z=-3.74, P=0.00). The objective visual functional parameters such as distance exophoria (P=0.83), near exophoria (P=0.88), distance esophoria (P=0.93), near esophoria (P=0.80), the fusion range (P=0.09), the accommodative convergence/accommodation (P=0.56), and the tear film breakup time (P=0.48) had no significant difference between the two groups. CONCLUSIONS: When the passively polarized 3D surgical imaging system was compared with the 2D surgical imaging system, although subjective feelings were uncomfortable, there was no objective evidence to indicate that the 3D surgical imaging system resulted in an increment of visual fatigue. The visual fatigue and discomforts were moderate and could be tolerated by the surgeons.

Good expert knowledge, small scope.

BACKGROUND: During many years of occupational stress research, mostly within the German governmental program for "Humanization of Work Life'', remarkable deficits concerning visual work were seen, the most striking being the lack of cooperation between the different experts. OBJECTIVE: With regard to this article hard arguments and ideas for solutions had to be found. METHODS/PARTICIPANTS: A pilot study in 21 enterprises was realized (1602 employees with different visual work tasks). A test set of screening parameters (visual acuity, refraction, phoria, binocular cooperation and efficiency, accommodation range and color vision) were measured. The glasses and/or contact lenses worn were registered and the visual tasks analyzed. In work at visual display units (VDU) the eye movements were recorded and standardized questionnaires were given (health, stress, visual work situation). Because of the heterogeneity of the sample only simple statistics were applied: in groups of different visual work the complaints, symptoms, hassles and uplifts were clustered (SAS software) and correlated with the results of the visual tests. Later a special project in 8 companies (676 employees) was carried out. The results were published in [14]. RESULTS: Discomfort and asthenopic symptoms could be seen as an interaction of the combination of tasks and working conditions with the clusters of individual functionalisms, frequently originating in postural compromises. Mainly three causes for stress could be identified: 1. demands inadequate with regard to intensity, resolution, amount and/or time structure; 2. prevention of elementary perceptive needs; 3. entire use of partial capacities of the visual organ. Symptoms also were correlated with heteronomy. Other findings: influence of adaptation/accommodation ratio, the distracting role of attractors, especially in multitasking jobs; influence of high luminance differences. Dry eyes were very common, they could be attributed to a high screen position, low light, monotonous tasks and office climate. For some parameters a diurnal rhythm could be identified. Nowhere special programs for ageing employees were found: the right glasses; retinal problems and signs of destabilization of vision. CONCLUSIONS: In all enterprises, the ergophthalmological and visual ergonomic knowledge of the occupational physicians was poor, visual ergonomists were not available and there was only very poor cooperation with ophthalmologists and optometrists, the first of whom additionally had not much knowledge of modern work.

Computer vision syndrome: a study of knowledge and practices in university students.

INTRODUCTION: Computer vision syndrome (CVS) is a condition in which a person experiences one or more of eye symptoms as a result of prolonged working on a computer. OBJECTIVES: To determine the prevalence of CVS symptoms, knowledge and practices of computer use in students studying in different universities in Malaysia, and to evaluate the association of various factors in computer use with the occurrence of symptoms. MATERIAL AND METHODS: In a cross sectional, questionnaire survey study, data was collected in college students regarding the demography, use of spectacles, duration of daily continuous use of computer, symptoms of CVS, preventive measures taken to reduce the symptoms, use of radiation filter on the computer screen, and lighting in the room. RESULTS: A total of 795 students, aged between 18 and 25 years, from five universities in Malaysia were surveyed. The prevalence of symptoms of CVS (one or more) was found to be 89.9%; the most disturbing symptom was headache (19.7%) followed by eye strain (16.4%). Students who used computer for more than 2 hours per day experienced significantly more symptoms of CVS (p=0.0001). Looking at far objects in-between the work was significantly (p=0.0008) associated with less frequency of CVS symptoms. The use of radiation filter on the screen (p=0.6777) did not help in reducing the CVS symptoms. CONCLUSION: Ninety percent of university students in Malaysia experienced symptoms related to CVS, which was seen more often in those who used computer for more than 2 hours continuously per day.

Management of paretic vertical deviations.

Paretic vertical deviations are characterized by complex patterns of incomitance that make them some of the most challenging strabismus problems to treat. Optimum results are obtained by performing surgery on those muscles, selected from among the eight cyclovertical muscles in the two eyes, that minimize the incomitance. In superior oblique paresis the additional factors of torticollis and torsion need to be addressed and aberrant regeneration can alter the surgical plan in third nerve paresis.

Effects of intraoperative breaks on mental and somatic operator fatigue: a randomized clinical trial.

BACKGROUND: Intermittent work breaks are common in fields with high workload but not yet for surgeons during operations. We evaluated the effects of intraoperative breaks during complex laparoscopic surgery (5 min every half hour) on the surgeon. METHODS: Fifty-one operations were randomized to a scheme with intraoperative breaks and release of the pneumoperitoneum (intermittent pneumoperitoneum (IPP)) or conventional conduct (CPP). Stress hormones and α-amylase were determined in the surgeon's saliva pre-, intra-, and postoperatively. Mental performance and error scores, musculoskeletal strain, and continuous ECG were secondary endpoints. RESULTS: Regular intraoperative breaks did not prolong the operation (IPP vs. CPP group: 176 vs. 180 min, p > 0.05). The surgeon's cortisol levels during the operation were reduced by 22 ± 10.3% in the IPP vs. the CPP group (p < 0.05). There were significantly fewer (p < 0.05) intraoperative events in the IPP vs. the CPP group, which yielded higher α-amylase peaks. The pre- to postoperative increase in the error rates of the bp-concentration test was fourfold reduced in the IPP group (p = 0.052). The relevant locomotive strain-scores were grossly reduced by IPP (p < 0.001). CONCLUSIONS: Our data support the idea that work breaks during complex laparoscopic surgery can reduce psychological stress and preserve performance without prolongation of the operation time compared with the traditional work scheme.

Effects of polyphenol on visual fatigue caused by VDT work.

Visual fatigue of VDT (visual display terminal) operators poses a serious problem for corporations where VDT work is a major part of operations. In this study, an investigation in a corporation was carried out to examine the effect of polyphenol on recovery from visual fatigue of the visual function caused by working at a VDT. Three kinds of parameters were used for evaluating the effect of polyphenol. As a subjective evaluation, the first was a questionnaire to ascertain subjective feelings of fatigue. As aspects of a physiological evaluation, the second and third parameters were the accommodative function and the flicker value.

[Ophthalmologist and "computer vision syndrome"]. / Oftalmologul practician si "computer vision syndrome".

The authors had tried to collect the data available on the Internet about a subject that we consider as being totally ignored in the Romanian scientific literature and unexpectedly insufficiently treated in the specialized ophthalmologic literature. Known in the specialty literature under the generic name of "Computer vision syndrome", it is defined by the American Optometric Association as a complex of eye and vision problems related to the activities which stress the near vision and which are experienced in relation, or during, the use of the computer. During the consultations we hear frequent complaints of eye-strain - asthenopia, headaches, blurred distance and/or near vision, dry and irritated eyes, slow refocusing, neck and backache, photophobia, sensation of diplopia, light sensitivity, and double vision, but because of the lack of information, we overlooked them too easily, without going thoroughly into the real motives. In most of the developed countries, there are recommendations issued by renowned medical associations with regard to the definition, the diagnosis, and the methods for the prevention, treatment and periodical control of the symptoms found in computer users, in conjunction with an extremely detailed ergonomic legislation. We found out that these problems incite a much too low interest in our country. We would like to rouse the interest of our ophthalmologist colleagues in the understanding and the recognition of these symptoms and in their treatment, or at least their improvement, through specialized measures or through the cooperation with our specialist occupational medicine colleagues.

Computer vision syndrome: a study of the knowledge, attitudes and practices in Indian ophthalmologists.

PURPOSE: To study the knowledge, attitude and practices (KAP) towards computer vision syndrome prevalent in Indian ophthalmologists and to assess whether 'computer use by practitioners' had any bearing on the knowledge and practices in computer vision syndrome (CVS). MATERIALS AND METHODS: A random KAP survey was carried out on 300 Indian ophthalmologists using a 34-point spot-questionnaire in January 2005. RESULTS: All the doctors who responded were aware of CVS. The chief presenting symptoms were eyestrain (97.8%), headache (82.1%), tiredness and burning sensation (79.1%), watering (66.4%) and redness (61.2%). Ophthalmologists using computers reported that focusing from distance to near and vice versa (P =0.006, chi2 test), blurred vision at a distance (P =0.016, chi2 test) and blepharospasm (P =0.026, chi2 test) formed part of the syndrome. The main mode of treatment used was tear substitutes. Half of ophthalmologists (50.7%) were not prescribing any spectacles. They did not have any preference for any special type of glasses (68.7%) or spectral filters. Computer-users were more likely to prescribe sedatives/anxiolytics (P = 0.04, chi2 test), spectacles (P = 0.02, chi2 test) and conscious frequent blinking (P = 0.003, chi2 test) than the non-computer-users. CONCLUSIONS: All respondents were aware of CVS. Confusion regarding treatment guidelines was observed in both groups. Computer-using ophthalmologists were more informed of symptoms and diagnostic signs but were misinformed about treatment modalities.