Differences in Eye Health, Access to Eye Care Specialists and Use of Lenses among Immigrant and Native-Born Workers in Spain.

Latin American immigrants make up 49% of the total immigrant population in Spain, yet little is known about their eye health. The aim of this study is to determine if there are differences in self-perceived eye health, access to eye care specialists, and use of lenses between a sample of Latin American immigrant workers from Colombia and Ecuador, and native-born workers in Spain. We used data from the PELFI cohort (Project for Longitudinal Studies of Immigrant Families). The sample consisted of 179 immigrant workers born in Colombia or Ecuador, and 83 Spanish-born workers. The outcome variables were self-perceived eye health, access to eye specialists, and use of lenses. A descriptive analysis of the sample was carried out, and the prevalence of the three outcome variables in immigrants and natives was calculated and adjusted for explanatory variables. Random effects logistic regression models examined eye health outcomes by workers' country of birth. Immigrants are less likely to report poor self-perceived eye health than native-born (ORc 0.46; CI 95%, 0.22-0.96). Furthermore, they have less access to specialists (ORc 2.61; CI 95%, 1.32-5.15) and a higher probability of needing lenses but not having them (ORc 14.14; CI 95%, 1.77-112.69). This latter variable remained statistically significant after adjusting for covariates (ORa 34.05; CI 95%, 1.59-729.04). Latin American immigrants may not value the use of lenses, despite eye care specialists indicating that they need them. Eye health education is required to recognize the importance of using lenses according to their visual needs.

Use of Magnifying Loupes among Dental Professionals.

AIM: The study aims to determine the perspective of dental professionals towards magnifying loupes and the selection criteria used while purchasing them. MATERIALS AND METHODS: In this regard, a close-ended questionnaire was structured and distributed among 111 dental professionals. The questionnaire was designed to obtain information regarding the usage of magnifying loupes in dental practices and procedures, limiting factors, and selection criteria for purchasing. The results obtained from this study were statistically analyzed with the help of SPSS. RESULTS: The findings illustrated that most respondents considered the use of magnifying loupes beneficial in dental practices. Also, 20.7% of them preferred "Through-the-Lens" magnifying loupes over "Flip-up" ones. Furthermore, many of the respondents considered that price, magnification, and resolution are the main factors in terms of selection criteria. CONCLUSION: Although, there is an immense growth seen in the usage of magnifying loupes in dentistry; still there is a need to increase the awareness of the dental professionals regarding the positive outcomes of magnification aids in dentistry. CLINICAL SIGNIFICANCE: The study will help enlightening clinicians regarding the selection criteria while purchasing magnifying loupes for dental practices.

The Effect of Magnification Loupes on Dental Hygienists' Posture while Exploring.

Purpose: The purpose of this study was to determine the effects of dental magnification loupes on posture during instrumentation.Methods: A convenience sample of 27 right-handed dental hygienists, with no prior history of injuries or disabilities of the head, neck, or trunk region, enrolled in the study. Baseline posture calibration was taken and tri-axial accelerometers were placed on four locations of the head and trunk (occipital region of head; cervical vertebrae C5; thoracic vertebrae T5; lumbar vertebrae L1) to measure acceleration and the orientation of the body to gravity. Participants were randomly assigned to wear self-supplied magnification loupes during either the first or second half of the session. Dental chair mounted typodonts, prepared with artificial calculus, were used to represent a simulated oral environment. Participants were asked to explore all areas of the mouth using an ODU 11/12 explorer. Mean accelerations of the three axes were used to compute average forward/backward (AP) and side to side (ML) tilt of each accelerometer recorded during the instrumentation sessions. An end-user opinion survey was completed by each participant at the conclusion of the session.Results: No statistically significant differences in posture were revealed between the sessions with the participants wearing their loupes and not wearing loupes. However, data from the end-user survey indicate that 74% of all the participants strongly agreed that magnification loupes made exploring easier and 67% strongly agreed that they felt that magnification loupes improved their posture.Conclusion: While the majority of participants perceived that their magnification loupes enhanced their posture and made exploring easier, data from this study provided little evidence to suggest that wearing loupes leads to improved body orientation. Future research needs to examine the declination angle of ergonomic loupes and its relationship to neck and trunk flexion.

Assessing the Use of Loupes and Lights in Dental Hygiene Educational Programs.

Purpose: The purpose of this study was to explore the use of loupes and lights in dental hygiene programs, to assess why they are being used, and to evaluate at what point in time they are introduced to students within the curriculum.Methods: A 20 question survey was developed and pilot tested. The survey was disseminated electronically to 335 dental hygiene program directors in the United States. Frequency distributions were analyzed to provide an overview of the data and Fisher's Exact Test was used to investigate differences between technical/community college programs and university-based programs.Results: Out of the 335 electronic surveys, 143 were completed for a response rate of 47%. Prevention of musculoskeletal disorders, ergonomics, and enhanced vision for instrumentation remain the top three advantages of using loupes. Ninety-six percent of respondents indicated students use loupes and over 50% of faculty use loupes. Fifty-seven percent of dental hygiene programs encourage students to purchase loupes with a light. Fifty percent of students pay $601-$900 for loupes and 47% pay $300-$600 for a light.Conclusion: Student and faculty use of loupes and lights are increasing in educational programs. Future research should focus on the longitudinal impact of using loupes/lights, the prevention of musculoskeletal disorders, and an investigation of the continued use of loupes in a professional setting post-graduation.

Introducing loupes to clinical practice: dental hygienists experiences and opinions.

OBJECTIVES: Recent literature has identified a number of potential advantages in wearing loupes for dental hygienists, including improved quality of care and ergonomics. The aim of the study was to determine dental hygienists' opinions about wearing loupes. METHODS: A short online survey was distributed to all dental hygienists who had recently participated in a study investigating the efficacy of loupes on musculoskeletal disorders; all had only worn loupes for a 6-month period, and prior to the study had not worn loupes. All of those invited completed the survey (n = 12), achieving a 100% response rate. RESULTS: The majority of respondents noted that the loupes were adaptable to wear; however, only one-quarter of hygienists surveyed were wearing them often following the study. Respondents identified that the biggest advantage to loupes was calculus removal (91.7%), and most indicated that they felt the quality of their work increased when wearing loupes (75%). The biggest disadvantage to wearing loupes was the adjustment period (50%), with limited depth of vision, headache, vertigo and infection control noted by at least one-third of respondents. CONCLUSIONS: This study revealed that hygienists identify both benefits and limitations to wearing loupes, and therefore, ongoing support may be required for hygienists adopting their use in clinical practice.

A Retrospective Study of Causes of Low Vision in Saud Arabia, A Case of Eye World Medical Complex in Riyadh.

Vision is the ability of seeing with a definite understanding of features, color and contrast, and to distinguish between objects visually. In the year 1999, the World Health Organization (WHO) and the International Agency for the Prevention of Blindness formulated a worldwide project for the eradication of preventable loss of sight with the subject of "Vision 2020: the Right to Sight". This global program aims to eradicate preventable loss of sight by the year 2020. This study was conducted to determine the main causes of low vision in Saudi Arabia and also to assess their visual improvement after using low vision aids (LVD).The study is a retrospective study and was conducted in low vision clinic at Eye World Medical Complex in Riyadh, Saudi Arabia. The file medical record of 280 patients attending low vision clinics from February 2008 to June 2010 was included. A data sheet was filled which include: age, gender, cause of low vision, unassisted visual acuity for long distances and short distances, low vision devices needed for long distances and short distances that provides best visual acuity. The result shows that the main cause of low vision was Optic atrophy (28.9%). Retinitis pigmentosa was the second cause of low vision, accounting for 73 patients (26%) followed by Diabetic retinopathy and Macular degeneration with 44 patients (15.7%) and 16 patients (5.7%) respectively. Inter family marriage could be one of the main causes of low vision. Public awareness should be embarked on for enlightenment on ocular diseases result in consanguineous marriage. Also, it is an important issue to start establishing low vision clinics in order to improve the situation.

Disposable optics for microscopy diagnostics.

The point-of-care testing (POCT) is having increasing role on modern health care systems due to a possibility to perform tests for patients conveniently and immediately. POCT includes lot of disposable devices because of the environment they are often used. For a disposable system to be reasonably utilized, it needs to be high in quality but low in price. Optics based POCT systems are interesting approach to be developed, and here we describe a low-cost fabrication process for microlens arrays for microscopy. Lens arrays having average lens diameter of 222 µm with 300 µm lens pitch were fabricated. The lenses were characterized to have standard deviation of 0.06 µm in height and 4.61 µm in diameter. The resolution limit of 3.9µm is demonstrated with real images, and the images were compared with ones made with glass and polycarbonate lens arrays. The image quality is at the same level than with the glass lenses and the manufacturing costs are very low, thus making them suitable for POCT applications.

Retina-like sensor based on a lens array with a large field of view.

This paper puts forward a retina-like sensor based on a lens array, which can be used in conventional optical systems. This sensor achieves log-polar mapping by dividing the imaging optical system's image plane using a lens array. In this paper the mathematical model has been set up with the relative structural parameters. Also, the simulation experiments and parameter analysis have been discussed to verify the reliability of this system. From the experiment results, it can be seen that this sensor realized the log-polar mapping with the transformed image output. Each lens corresponded to a circular region in the image plane with no crossover between different fields of view of adjacent lenses. When the number of rings changed, the relative error did not significantly change, and this error could be reduced to 1% when the number of lenses in each ring was increased. The work widely enlarged the application of this kind of sensor, which will lay a theoretical foundation for retina-like sensors.

Current trends in endodontic treatment by general dental practitioners: report of a United States national survey.

INTRODUCTION: In the United States almost 70% of root canal treatment (RCT) is performed by general dentists (GPs), yet little is known about their treatment protocols. METHODS: A paper survey was mailed to 2000 United States GPs with questions about the types of endodontic cases treated, routine treatment protocols, use of newer technologies, and endodontic continuing education (CE). RESULTS: Completed surveys were returned by 479 respondents (24%). GPs who perform RCT (84%) reported providing anterior (99%), bicuspid (95%), and molar (62%) RCT and retreatment (18%). Rubber dam was used always (60%), usually (16%), sometimes (13%), and never (11%). Newer technologies used by GPs included digital radiography (72%), magnification (80%), electronic apex locator (70%), and nickel-titanium rotary instrumentation (74%). Compared with GPs with >20 years of experience, those in practice for ≤10 years were more likely to use rubber dam (P < .05), nickel-titanium rotary instrumentation (P < .001), apex locators (P < .001), and magnification (P < .01); in contradistinction, GPs in practice >20 years were more likely to perform retreatments (P < .05). Women were less likely to perform retreatment or molar RCT (both P < .05). GPs with >5 hours of CE were more likely to use rotary instrumentation (P < .001), irrigant activation devices (P < .01), and apex locators (P < .001) and perform molar RCT (P < .001) and retreatment (P < .05), but no more likely to use rubber dam. CONCLUSIONS: Recent GP graduates (≤10 years) were more likely to adopt new technologies and use rubber dam than those who practiced for >20 years. More experienced GPs were more likely to take on complicated cases than those with fewer years of practice. There was no association between hours of CE and compliance with rubber dam usage.

Occupational ocular accidents amongst Greek endodontists: a national questionnaire survey.

AIM: To investigate amongst Greek endodontists, the incidence of ocular accidents during practice, the circumstances associated with them, the therapeutic measures taken after the accidents, their compliance with the use of eye protection and their eye care behaviour. METHODOLOGY: One hundred and forty-seven endodontists met the inclusion criteria and were invited to participate in the survey. Data were gathered through interviews based on a questionnaire. Participants were asked for personal/professional data, information on ocular accidents in the past 5 years, post-accident actions and the type of eye protection used. Their eyesight status and frequency of ocular examination were also recorded. Data were analysed using chi-square test, independent samples t-test and logistic regression. The level of significance was set at P = 0.05. RESULTS: The response rate was 84%. Ocular accidents were reported by 73% of the participants. Amalgam and NaOCl were the foreign bodies most frequently associated with ocular accidents. Medical assistance was sought in 16% of the most recent accidents. No permanent eye damage was reported. Regular use of magnification (OR:0.305, 95%CI:0.123-0.754) and years of clinical experience (OR:0.191, 95%CI:0.066-0.551) were significant predictors for the incidence of ocular accidents. Adequate eye protection was utilized by 82% of endodontists. Endodontists with eyesight deficiencies attended more frequently for ocular examination (P = 0.018). CONCLUSION: A high percentage of endodontists experienced ocular accidents. Regular use of magnification and increasing years in practice were associated with a reduced risk of ocular accidents. The majority of endodontists reported using adequate eye protection.

Use of dental loupes among dental trainers and trainees in the UK.

INTRODUCTION: Magnification loupes are used in dentistry where increased visual performance is needed. The interest and use of loupes among dental practitioners and students appears to be growing. Despite this little quantitative data regarding the use of loupes in clinical practice and factors governing their purchase among dental trainers and trainees is available. OBJECTIVE: To determine the extent of use of loupes among dental trainers and trainees in the UK and identify what factors influence their choice of selection. METHOD: A proforma questionnaire was designed to collect the information required and was handed out dental trainers and trainees. RESULTS: Use of loupes is more common among the dental trainers (44%) than trainees (28%). Of the nonusers, increased interest among the trainees (83.6%) and trainers (50%) in purchasing loupes was noted. Price was found to be the most important factor during purchase. The majority of users opted for 2.5×; and a light source was a popular choice. Both users and nonusers in the study group had an affinity towards "through-the-lens" type. No significant variation in back/neck discomfort between the users and nonusers was found. CONCLUSION: Use of loupes among dental trainers and trainees remains low. Reduction in price and provision of information could increase the number of loupe users.

Magnification loupes in U.S. entry-level dental hygiene programs--occupational health and safety.

PURPOSE: The purpose of this study was to determine policies and practices regarding magnification loupes among faculty and students in accredited dental hygiene programs as measured by a 31 item, self-designed questionnaire. In addition, the study compared policies among dental hygiene programs in 2 year versus 4 year programs in terms of requirements for the use of magnification loupes. METHODS: After institutional review board approval, a 31 item self-designed questionnaire was emailed via Survey Monkey to 303 entry-level dental hygiene programs. An overall response rate of 75% was obtained. Data were analyzed using descriptive statistics and chi-square test of independence. RESULTS: Results reveal the vast majority of programs do not require loupes for faculty or students, with only 23% of responding schools requiring students to purchase loupes and 8% requiring faculty to use loupes. More dental hygiene programs require students to wear loupes than require faculty to wear loupes. No statistically significant differences (p-value=0.54) in program policies were found requiring the purchase of magnifying loupes by students, based on 2 year and 4 year dental hygiene educational programs. Odds ratio (1.25) give the odds of students purchasing loupes in a 2 year program as 25% higher than a 4 year program. Almost two thirds of respondents reported loupes instruction as a curriculum component, although most respondents spent 2 or less hours teaching in this area. Most programs (90%) do not plan to require students to purchase loupes in the future, although the majority believes proper use of loupes should be integrated in the curriculum. CONCLUSION: Most respondents see advantages to loupes, but clinical policies on loupes do not appear to correlate with beliefs. Educational programs in dental hygiene seem slow to adopt and require the use of loupes. Current clinical polices on loupes should be reviewed to ensure graduates experience the potential ergonomic benefits magnification brings to clinical practice during their education.

Testing of Lagrange multiplier damped least-squares control algorithm for woofer-tweeter adaptive optics.

A Lagrange multiplier-based damped least-squares control algorithm for woofer-tweeter (W-T) dual deformable-mirror (DM) adaptive optics (AO) is tested with a breadboard system. We show that the algorithm can complementarily command the two DMs to correct wavefront aberrations within a single optimization process: the woofer DM correcting the high-stroke, low-order aberrations, and the tweeter DM correcting the low-stroke, high-order aberrations. The optimal damping factor for a DM is found to be the median of the eigenvalue spectrum of the influence matrix of that DM. Wavefront control accuracy is maximized with the optimized control parameters. For the breadboard system, the residual wavefront error can be controlled to the precision of 0.03 µm in root mean square. The W-T dual-DM AO has applications in both ophthalmology and astronomy.

New method for determining the depth of field of microscope systems.

This paper presents new formulas to determine the depth of field (DOF) of optical and digital microscope systems. Unlike the conventional DOF formula, the new methods consider the interplay of geometric and diffraction optics for infinite and finite optical microscopes and for corresponding digital microscope systems. It is shown that in addition to the well understood parameters such as numerical apertures, focal length, and light wavelength, system components such as aperture stops also affect the DOF. For the same objective lens, the DOF is inversely proportional to the size of the aperture stop, and it is proportional to the focal length of the ocular lens. It is also shown that under optimal viewing and operating conditions, the visual accommodation of human observers has no meaningful impact on DOF. The new formulas reported are useful for accurately calculating the DOF of microscopes.

Applications of adaptive optics scanning laser ophthalmoscopy.

Adaptive optics (AO) describes a set of tools to correct or control aberrations in any optical system. In the eye, AO allows for precise control of the ocular aberrations. If used to correct aberrations over a large pupil, for example, cellular level resolution in retinal images can be achieved. AO systems have been demonstrated for advanced ophthalmoscopy as well as for testing and/or improving vision. In fact, AO can be integrated to any ophthalmic instrument where the optics of the eye is involved, with a scope of applications ranging from phoropters to optical coherence tomography systems. In this article, I discuss the applications and advantages of using AO in a specific system, the AO scanning laser ophthalmoscope. Since the Borish award was, in part, awarded to me because of this effort, I felt it appropriate to select this as the topic for this article. Furthermore, users of AO scanning laser ophthalmoscope continue to appreciate the benefits of the technology, some of which were not anticipated at the time of development, and so it is time to revisit this topic and summarize them in a single article.

A critical evaluation of the evidence supporting the practice of behavioural vision therapy.

In 2000, the UK's College of Optometrists commissioned a report to critically evaluate the theory and practice of behavioural optometry. The report which followed Jennings (2000; Behavioural optometry--a critical review. Optom. Pract. 1: 67) concluded that there was a lack of controlled clinical trials to support behavioural management strategies. The purpose of this report was to evaluate the evidence in support of behavioural approaches as it stands in 2008. The available evidence was reviewed under 10 headings, selected because they represent patient groups/conditions that behavioural optometrists are treating, or because they represent approaches to treatment that have been advocated in the behavioural literature. The headings selected were: (1) vision therapy for accommodation/vergence disorders; (2) the underachieving child; (3) prisms for near binocular disorders and for producing postural change; (4) near point stress and low-plus prescriptions; (5) use of low-plus lenses at near to slow the progression of myopia; (6) therapy to reduce myopia; (7) behavioural approaches to the treatment of strabismus and amblyopia; (8) training central and peripheral awareness and syntonics; (9) sports vision therapy; (10) neurological disorders and neuro-rehabilitation after trauma/stroke. There is a continued paucity of controlled trials in the literature to support behavioural optometry approaches. Although there are areas where the available evidence is consistent with claims made by behavioural optometrists (most notably in relation to the treatment of convergence insufficiency, the use of yoked prisms in neurological patients, and in vision rehabilitation after brain disease/injury), a large majority of behavioural management approaches are not evidence-based, and thus cannot be advocated.

The number of discernible colors perceived by dichromats in natural scenes and the effects of colored lenses.

The number of discernible colors perceived by normal trichromats when viewing natural scenes can be estimated by analyzing idealized color volumes or hyperspectral data obtained from actual scenes. The purpose of the present work was to estimate the relative impairment in chromatic diversity experienced by dichromats when viewing natural scenes and to investigate the effects of colored lenses. The estimates were obtained computationally from the analysis of hyperspectral images of natural scenes and using a quantitative model of dichromats' vision. The color volume corresponding to each scene was represented in CIELAB color space and segmented into cubes of unitary side. For normal trichromats, the number of discernible colors was estimated by counting the number of non-empty cubes. For dichromats, an algorithm simulating for normal observers the appearance of the scenes for dichromats was used, and the number of discernible colors was then counted as for normal trichromats. The effects of colored lenses were estimated by prior filtering the spectral radiance from the scenes with the spectral transmittance function of the lenses. It was found that in dichromatic vision the number of discernible colors was about 7% of normal trichromatic vision. With some colored lenses considerable improvements in chromatic diversity were obtained for trichromats; for dichromats, however, only modest improvements could be obtained with efficiency levels dependent on the combination of scene, lens and type of deficiency.

Magnification in dental practice and education: experience and attitudes of a dental school faculty.

The routine use of magnification and enhanced lighting by oral health care providers, educators, and students is growing, but there is little consensus regarding its implementation and use. Many students and faculty at the Temple University Kornberg School of Dentistry elect to use some form of magnification in their real and simulated patient care activities, even though the school does not mandate or suggest standards for its utilization. A questionnaire was administered to the clinical faculty to assess two parameters: experience with magnification, and attitudes concerning the value of enhanced vision. Eighty-two out of 124 eligible participants completed the questionnaire successfully for a 66 percent return rate. Sixty-one percent of respondents reported their primary practice or teaching activities as "general dentistry or restorative/prosthodontics." The remainder of the respondents represented a cross-section of other departments and specialists. All endodontists and periodontists who completed the survey and 56 percent of the general/restorative dentists indicated they use magnification. This group accounted for 91 percent of all magnification users. Thirty-nine percent in the magnification users group indicated that they avoid using magnification for some procedures. Faculty magnification users are not in full agreement about the value of enhanced vision in a dental education program. Nearly one-quarter of all magnification users indicated it is unlikely they would use magnification in the teaching environment, even though they may use it in private practice. Various explanations were given for this inconsistency. Only 61 percent of magnification users indicated they make a point to talk to students about the uses and benefits of magnification. While 91 percent of users said that magnification offers significant benefits, only 73 percent believe it should be a program requirement, and 61 percent think it should be required beginning in the first year of the curriculum. The findings of this survey suggest that educational institutions would be wise to address faculty concerns and reasons for resistance before moving to the mandated use of magnification.

Dental hygienists' opinions about loupes in education.

PURPOSE: The present study was conducted in order to explore dental Hygienists' perceptions of the advantages and disadvantages of loupes, and the extent to which dental hygienists believe loupes should be utilized in the educational setting. METHODS: Dental hygienists were contacted through a popular dental hygiene website and were asked to participate in a survey regarding the use of loupes. Eight hundred sixty-eight valid surveys were completed. Participants were asked to indicate the extent to which they use loupes, the environments in which they have used loupes, when they think loupes should be introduced to students in dental hygiene school, and the advantages and disadvantages of using loupes. RESULTS: Results indicated approximately 60.5% of practicing dental hygienists surveyed for the study always or sometimes use loupes, however only 21% had actually used loupes as a student. A number of differences were found between those respondents who use loupes and those who do not use loupes in regards to how they believe loupes should be used in education. Alleged advantages of using loupes received much greater support than alleged disadvantages. Members of the American Dental Hygienists' Association (ADHA) were much more likely to always use loupes than non-ADHA respondents. CONCLUSION: Dental hygienists participating in the survey believe that loupes should be introduced to dental hygiene students, although many believe using loupes should be an option while in school. Wide agreement exists among dental hygienists in regards to the advantages of using loupes. The authors contend that loupes are a vital tool that students should learn how to use, but the use of loupes should be optional once a student has learned how to use them properly.

[Utilization of optical devices and equipments by students with visual impairment]. / Utilização de recursos ópticos e equipamentos por escolares com deficiência visual.

PURPOSE: To verify perceptions and conduct of students with visual impairment regarding devices and equipment utilized in schooling process. METHODS: A transversal descriptive study on a population of 12-year-old or older students in schooling process, affected by congenital or acquired visual impairment, inserted in the government teaching system of Campinas during the year 2000. An interview quiz, created based on an exploratory study was applied. RESULTS: A group of 26 students, 46% of them with low vision and 53.8% affected by blindness was obtained. Most of the students were from fundamental teaching courses (65.4%), studying in schools with classrooms provided with devices (73.1%). Among the resources used in reading and writing activities, 94.1% of the students reported they used the Braille system and 81.8% reported that the reading subject was dictated by a colleague. Most of the students with low vision wore glasses (91.7%), and 33.3% utilized a magnifying glass as optical devices. Among the non-optical devices, the most common were the environmental ones, getting closer to the blackboard (75.0%) and to the window (66.7%) for better lighting. CONCLUSIONS: It became evident that students with low vision eye-sight made use of devices meant for bearers of blindness, such as applying the Braille system. A reduced number of low vision students making use of optical and non-optical devices applicable to their problems were observed, indicating a probable unawareness of their visual potential and the appropriate devices to improve efficiency.