With a national population now estimated at 1.1 billion people (and growing!), it is often stated that India accounts for 1/3 of all blind and visually impaired individuals in this world! If this statement is correct, this means that there are 5–6 million visually impaired and blind individuals in India. Although certainly real progress is being made, one can reasonably ask, is the existing organizational structure designed to serve the needs of so large a number of people, and are the necessary care-providers available to provide for visual rehabilitation requirements of this very substantial cohort of affected patients? Both continuing growth and aging of the Indian population tend to challenge the capacity of that nation to meet demands for ophthalmic services, as well as their ability to meet the visual rehabilitation requirements of this populace. Modern optometry is, in many ways, a nascent profession in India. On behalf of the large cohort of visually impaired patients, I argue that a difference can be made through effective inter-professional cooperation between emerging modern optometry and more developed ophthalmology. I hope to see an increasing role for optometry in the provision of care for the visually impaired and blind in coming years. Here, I discuss a number of issues pertinent to the needs of the blind and visually impaired population, as well as means for enhancing applicable rehabilitation services.
Background: Loss of vision influences the educational opportunities, employment, and social life of children. We sought to determine the change in educational opportunities among Tanzanian school age children with congenital/developmental cataract following surgery. Materials and Methods: A cross-sectional study was conducted among parents of children age 6–16 years who had congenital/developmental cataract surgery at KCMC Hospital. A consecutive list of children was obtained, and preoperative and postoperative clinical data (including visual acuity) was abstracted from files. Parents of identified children were interviewed using a pre-tested, standardized questionnaire, and findings were assessed to determine level of improvement in educational environment. Results: Seventy-two children and their parents were enrolled. There were significant improvements in vision of children; however, there was a four-fold increase in the number of children now attending schools for the blind. Fourteen of the nineteen children in schools for the blind had a vision of 6/60 or better. Demographic characteristics of the children or families did not predict placement. Conclusion: There appears to be considerable inappropriate educational placement of children following cataract surgery. Additional research is needed to better understand the decisions behind educational placement.
This review aims at uncovering certain aspects of the historical evolution of a subject that is so familiar that we rarely stop to think about its background. That subject is Visual Acuity Measurement. The history will show how innovative ideas that were ignored when first proposed were eagerly adopted when they were reintroduced later. It will also show the role of vision rehabilitation in preparing the way for the current standards.
BACKGROUND: In many states of the U.S.A., people with moderately reduced visual acuity e.g., 20/50 - 20/200) can legally drive with the aid of a small, spectacle-mounted ("bioptic") telescope. We conducted a demonstration project to assess the viability of implementing bioptic driving in The Netherlands. In this paper we describe the framework of the project from conception through to realization of our primary objective - the introduction of bioptic driving as a legal option for visually impaired people in The Netherlands. METHODS: The project was based on bioptic driving programs in the U.S.A., which were adapted to fit within current driving training and assessment practices in The Netherlands. The project convened a consortium of organizations including the Netherlands Bureau of Driving Skills Certificates (CBR), service organizations for the visually impaired, and research departments at universities investigating driving and vision. All organizations were educated about bioptic driving and participating professionals were trained in their specific aspects of the project. Media publicity led to significant interest and helped recruitment that enabled the screening and selection of potential participants. OUTCOMES: The project demonstrated that people with moderately reduced visual acuity can be trained to achieve an adequate level of proficient and safe driving (as assessed by the local official driving licensing professionals) when using a bioptic telescope for the road conditions in the Netherlands. Based on the successful project outcomes, a request was made to the Minister to allow bioptic driving in the Netherlands. This request has been accepted; the legal procedures for implementation are in process.
Communication impairments pose a major threat to an individual's quality of life. However, the impact of visual impairments on communication is not well understood, despite the important role that vision plays in the perception of speech. Here we present 2 experiments examining the impact of discrete central scotomas on speech perception. In the first experiment, 4 patients with central vision loss due to unilateral macular holes identified utterances with conflicting auditory-visual information, while simultaneously having their eye movements recorded. Each eye was tested individually. Three participants showed similar speech perception with both the impaired eye and the unaffected eye. For 1 participant, speech perception was disrupted by the scotoma because the participant did not shift gaze to avoid obscuring the talker's mouth with the scotoma. In the second experiment, 12 undergraduate students with gaze-contingent artificial scotomas (10 visual degrees in diameter) identified sentences in background noise. These larger scotomas disrupted speech perception, but some participants overcame this by adopting a gaze strategy whereby they shifted gaze to prevent obscuring important regions of the face such as the mouth. Participants who did not spontaneously adopt an adaptive gaze strategy did not learn to do so over the course of 5 days; however, participants who began with adaptive gaze strategies became more consistent in their gaze location. These findings confirm that peripheral vision is sufficient for perception of most visual information in speech, and suggest that training in gaze strategy may be worthwhile for individuals with communication deficits due to visual impairments.
Gordon E. Legge, PhD University of Minnesota This paper presents an edited, timeline chronology of the important developments in the field of low vision. The history of any discipline is inherently worth recording, although we recognize that what is history to one person may be trivia to another. To help preserve the history of low vision we have developed a timeline of events we consider to be significant in the development of the field. Since our viewpoint may well be limited in scope, or at odds with the views of others, we have chosen to present the timeline as an interactive document. The timeline is brought to each International Conference on Low Vision where an opportunity is provided for attendees to edit the timeline. The current timeline was edited following the Vision 2002 conference in Sweden and again following the Vision 2005 Conference in London. It has been further edited following the Vision 2008 conference held in Montreal, Canada. We will continue this process at the 2011 conference in Kuala Lumpur, Malaysia. In the interim we offer the timeline as an open access document in the hopes that it will provide historical information and an expanded opportunity for input. Those seeking to add information or contest the inclusion of items may do so by emailing detailed comments to the corresponding authors (addresses are supplied at the end of this document). Please include source documentation or URL addresses where appropriate. Thank you. We hope you find this document informative and thought provoking.
Background: In Europe, driving a passenger car is prohibited if binocular best corrected visual acuity (BCVA) is below 0.5 (20/40). Some US states allow people with reduced visual acuity to use a bioptic telescope system when driving. The aim of our study is to introduce a bioptic telescope system for driving in the Netherlands and to investigate whether it enables people with reduced visual acuity to gain sufficient practical fitness to drive in a European setting. Results: Out of 378 persons who applied for information following media attention for the project, 160 candidates volunteered to participate. Based on the available information, 36 subjects (binocular BCVA: 0.16–0.5 [20/125–20/40]) were invited for assessment (vision, mobility, cognitive function, and driving skills). Of these, 16 did not meet the inclusion criteria and 2 decided not to participate. The remaining 18 subjects were trained in the use of a monocular bioptic telescope (3× magnification). They all completed the predriving training successfully and received driving lessons from specialized professional driving instructors. Eventually, 9 subjects passed the official on-road test of practical fitness to drive, 7 were excluded after a number of driving lessons, and another 2 withdrew on their own initiative. Conclusion: This is the first study in Europe to prepare subjects with reduced visual acuity to drive with the use of a bioptic telescope system. About 55% of the preselected subjects fulfilled all inclusion criteria. Half of the subjects who entered the bioptic training program passed the official fitness to drive test, demonstrating that they could drive smoothly and safely in Dutch traffic using a bioptic telescope system.
Purpose: In visually impaired older patients, it is unclear which co-existing conditions patients suffer from and whether all co-existing conditions are reported by the patient. Our purpose was to present the level of agreement between patients' and their general practitioners' co-morbidity reports. Methods: Analyses were performed on data from an observational study among 296 visually impaired older patients. Agreement between patients and 165 general practitioners was obtained from twelve (chronic) condition categories. Cohen's Kappa was used to assess the level of agreement. Results: Patients reported a median number of co-existing conditions of 1 (range: 0–4) and general practitioners 3 (range: 0–7). Agreement was ‘very good’ for diabetes (Kappa 0.82; 95% CI [0.73;0.92]) and ‘moderate’ for heart conditions (Kappa 0.48; 95% CI [0.33;0.62]) and COPD or asthma (Kappa 0.60; 95% CI [0.45;0.75]). Kappa values were ‘fair’ (0.29 to 0.34) for cancer, musculo-skeletal conditions, hearing impairments and stroke,...
In the course of a broader study investigating functional vision in low-vision subjects, we compared the chromatic and achromatic contrast sensitivities of 12 subjects with age-related macular degeneration (AMD; mean age: 75 years) with those of two control groups. One group comprised age-matched individuals with a mean age of 77 years, while the other had a mean age of 46 years. Contrast sensitivities were measured as a function of spatial frequency of sinusoidal gratings. Sensitivity to achromatic luminance contrast was severely reduced in the AMD subjects compared to both control groups, particularly for the higher and medium spatial frequencies. It was reduced to an average value of less than 10% of the age-matched normal group at 4 c/deg. At low spatial frequencies, achromatic contrast sensitivity was less affected. At 0.4 c/deg, for example, the AMD subjects showed on the average 30% of normal achromatic sensitivity, whereas sensitivity to isoluminant red-green and yellow-blue cone contrast was only about 10% of that of the age-matched normal value. This represents a significantly greater impairment of chromatic than of achromatic discrimination at low spatial frequencies in AMD.
Purpose: To evaluate the prevalence of cognitive impairment among patients at a low-vision clinic and to determine whether low-vision rehabilitation (LVR) strategies improve visual function in these patients. Methods: We studied 50 consecutive patients presenting to a low-vision clinic. Folstein's Mini-Mental State Examination (MMSE) was administered to screen for cognitive impairment. During the low-vision examination, visual acuity was measured with and without the use of optical low-vision aids. The percentage visual acuity improvement with the use of low-vision aids was calculated for each patient. Results: Of the 50 patients examined, 16 (32%) had an MMSE score less than 24. Of these 16 patients, 14 (87.5%) experienced an improvement in visual acuity using low-vision devices. The visual acuity improvement with low-vision aids was statistically significant (p < 0.0001). Five of the 50 (10%) patients had MMSE scores less than 21. All five of these patients had improved visual acuity and function with l...
Objectives: To identify the perceived barriers to the provision of clinical low-vision service among ophthalmologists in Nigeria, with a view to proffering measures for their removal. Methods: A cross-sectional survey of ophthalmologists attending the Annual Ophthalmological Society of Nigeria Congress in September 2005 was conducted. Using self-administered questionnaires, information relevant to low-vision practice and the perceived barriers to the provision of low-vision services was garnered. Results: Eighty-three (70.9%) ophthalmologists out of 117 eligible participants at the congress responded to all of the questions and returned the study questionnaires. Non-availability of low-vision devices within the country (88%), lack of training in low-vision care (73.5%), lack of public awareness of low-vision care and its practitioners (60.2%), and the ophthalmologists' preoccupation with general ophthalmic practice (56.6%) were cited as the major barriers. With regard to the fellows and the residents in training, there was a statistically significant difference in their perception of two of the investigated barriers, namely, that low-vision care is not lucrative (T value: 4.46; 95% CI: 0.16± 0.07) and low-vision care is time-consuming (T value: 2.05; 95% CI: 0.145± 0.14). Conclusion: Training in low-vision care should be provided within the country for interested relevant personnel at all levels. Moreover, low-vision devices should be made accessible and available to the practitioners. There is a need in Nigeria for widespread health education/awareness campaigns in low-vision care, targeted primarily at ophthalmologists, allied eye-care providers, and the general public. There is a need to include low-vision practice in the curriculum of the ophthalmology residency program in Nigeria. Further qualitative research may need to be conducted to explain the differences in responses between subsets of the study population.
Background: As the prevalence of visual impairment rapidly increases, the services offered by the Canadian National Institute for the Blind (CNIB) will become even more important. As most clients are referred to the CNIB by their ophthalmologist or optometrist, maximising the efficiency of these referrals is the first step in the appropriate delivery of CNIB low vision rehabilitation services. This pilot study examined the barriers that prevent ideal referral practices by ophthalmologists in the Greater Toronto Area to the Toronto District CNIB. Methods: A survey questionnaire was completed by 29 Toronto-area ophthalmologists identified in a simple random sample. Results: Key barriers to referral included misconceptions regarding referral criterion and lack of information regarding CNIB services. Interpretation: Resulting recommendations included an educational campaign to teach Toronto-area ophthalmologists about CNIB services, as well as the necessary criteria for referring patients. There is no minimum level of visual functioning necessary before making a referral to the CNIB. Patients should be referred early in the disease process in order to optimise the delivery of visual rehabilitation and other services.
Background: It is known that unmet expectations are a common cause of patient dissatisfaction with health care. The purpose of this study was to determine the expectations of patients attending their first low vision clinic appointment in a specialist ophthalmic hospital and to determine how well their expectations were met by the low vision clinic. Method: Fifteen adults with age-related macular degeneration (AMD) and significant vision loss were recruited. A one-to-one, semistructured interview was performed by a research psychologist to determine the difficulties patients were experiencing and their expectations of the low vision clinic. At a further interview 3 months later patients were again asked what difficulties they were experiencing and to comment on the perceived benefits of the low vision clinic. Results: Ninety-three percent (93%) (14/15) reported difficulty with reading. Other frequently reported problems included shopping (7/15), face recognition (5/15), crossing roads (4/15) and television (4/15). Seven patients (47%) expected to be prescribed new conventional spectacles to overcome these difficulties. Only 4 (27%) expected to receive magnifiers, 2 expected advice and 1 expected to receive a closed-circuit television magnifier. The most frequently reported benefit from the clinic was in extra help with reading or writing (6 participants; 40%). Eight patients would unequivocally recommend the low vision clinic to a friend or family member with similar vision, and only 3 (20%) would not recommend the low vision clinic. Conclusions: Whilst most patients attending a low vision clinic have visual problems amenable to low vision rehabilitation, many have false expectations of the purpose of the clinic. In particular, many expect conventional spectacles to ameliorate their visual disability. Despite this, most patients would recommend a friend with similar vision to attend the low vision clinic.
Purpose: Because magnification ratios (MRs) indicated (IMRs) in catalogues of “Head and Attachment Magnifiers” made by Eschenbach are not common values, we examined the IMRs in relation to the working distances (WDs) indicated (IWDs) in the catalogues and then calculated the corrected WDs. Methods: From information about loupes given in the catalogues and measurements made with a lensometer, we determined (1) the power of each magnifier and (2) the accommodation needed; we then (3) calculated the MR and (4) established the corrected WD. Results: When used within the IWD, monocular loupe had an MR that was the same as the IMR. However, for binocular loupes, the MR was lower than the IMR. When the loupes were used at the revised WD recommended by the engineer of Eschenbach, binocular loupes had an IMR of “–1,” meaning that a WD shorter than the revised WD was needed to attain the IMR. Conclusion: With Eschenbach head and attachment magnifiers, the IMR is only attained when viewed at a shorter WD than that indicated in the catalogue (IWD) and with adequate accommodation.
An electronic survey was designed and completed by 100 ophthalmologists to characterize the magnitude and living environments of end-stage glaucoma patients and identify key factors that may influence the general ophthalmologists' referral patterns for low vision care (LVC) services. Seventeen percent of the respondents completed a glaucoma fellowship, and 10% indicated membership and active participation in the American Glaucoma Society. One hundred ophthalmologists who responded to the survey estimated they saw on average over 150 glaucoma patients per year and diagnosed between 20 and 50 patients annually with glaucoma. Of their patients with glaucoma, an estimated 12% had end-stage glaucoma. Sixty percent of the end-stage glaucoma patients experienced field loss that impacted their ability to live independently thereby requiring assistance from family, nursing homes, hospitals, shelters, or assisted living in 51% of the cases. However, only 45% of the end-stage glaucoma patients were referred for LVC services according to the survey. Patients who are self motivated, have difficulty with everyday activities, and those who request improvements in their vision are the most likely to be referred for LVC services, while location, availability, and patient hesitation are the primary obstacles hindering end-stage glaucoma patients from receiving LVC services. While LVC are needed by the numerous sufferers with end-stage glaucoma, these services are under-utilized due to a variety of factors hindering a patient from receiving a referral.
Considerable research indicates that spatial hearing in people who are blind is similar to or better than that of people who are sighted. Of particular relevance to everyday function is an individual's self-assessment of sound localization skills. In the present study, questionnaire responses by people with self-reported blindness and normal hearing indicated high self-ratings of spatial hearing skills among those who responded to the survey. Ratings for several spatial hearing situations were compared with ratings obtained from a different study of sighted individuals.
Background: Public understanding of age-related macular degeneration (AMD) is lower than that of other eye diseases such as cataract or glaucoma. The purpose of this study was to determine what reasons people with AMD give for their vision loss. Methods: Fifteen adults with AMD causing significant visual loss performed a detailed one-to-one semi-structured interview. Qualitative analysis techniques were used to identify themes and frequency of responses. Results: Sixty percent (9/15) of the participants identified aging as the principal cause of their vision loss. Two participants (13%) volunteered smoking as being a contributing factor. Common misconceptions included vision loss being attributable to trauma (2/15), medical or surgical intervention (2/15), and overuse of the eyes in earlier life (2/15). No patients mentioned genetic factors as being of importance. Conclusion: Patients with macular disease attribute their vision loss to many factors. Less than two-thirds identify their vision problem as being related to aging. Few appear to be aware of the role of smoking in AMD pathogenesis, and many feel their vision loss is due to medical intervention, trauma, or "using up" their vision. Low-vision practitioners should ensure that patients are correctly counseled as to the cause of their vision loss. Patient education with regard to AMD needs to be made more available in a clinical setting and in health information campaigns.
This study, carried out by the Edinburgh Visual Impairment Research Group with outpatients of the Princess Alexandra Eye Pavilion (Edinburgh, Scotland), focuses on the relationship between low vision, travel behaviour, and quality-of-life issues. The study was part of a wider investigation into the functional and quality-of-life benefits of cataract surgery for patients with age-related macular degeneration. Each patient was asked to complete a travel diary for the previous week and answer a mobility questionnaire as part of an interview session.The aim of the study was to identify the personal, environmental, and transportation factors that have an impact on visually impaired people's mobility and independence. The analysis has demonstrated that there are different subgroups of patients with different patterns of travel behaviour. While aspects of the built environment and transport system such as controlled road crossings and location of bus stops play an important role in determining the travel behaviour of visually impaired people, there is a personal factor involving a combination of age and vision in the better eye that best explains the travel behaviour patterns of visually impaired people.
This paper discusses the outcomes of a recent state-of-the-science conference on rehabilitation technology and methods in blindness and low vision. The conference goals were to assess the current state of the art and identify the gaps where research or other action is needed. To ensure that real needs were addressed, a third of the participants were blind or visually impaired, while another third were involved in rehabilitation service delivery. Topics addressed included infancy and school-age needs, travel, information access, vocational and daily living needs, access to graphical information, disease and deficit-specific problems and solutions, and functional assessment. In addition to identifying many research needs in these areas, an emerging theme was the need to adjust future research agendas to address changes in the target population, such as the increasing prevalence of dual sensory loss and multiple disabilities. Also sorely needed is improved communication among the various stakeholders in the visual impairment field (consumers, clinicians, teachers, rehabilitation service providers, researchers, and industry) in order to more effectively harness what knowledge already exists and reduce avoidable barriers such as inaccessible consumer product design.
Introduction: Adults with learning disabilities find it difficult to access conventional eye care services. The result is that refractive errors remain uncorrected, treatable pathology goes undetected and visual acuities are suboptimal. Impaired vision limits independence and impacts significantly on quality of life. Methodology: The demographic and visual characteristics of 95 adults with learning disabilities attending a specialist multi-professional visual assessment clinic within a day centre in Belfast were examined and issues relating to co-operation, access and communication addressed. Results: Of the 95 patients assessed, 51(53.7%) were male and the mean age was 38.13 ± 10.71 years (range: 19–65 years). In 43.2% (n = 41) of cases, there had been no previous visual assessment. Only 30.6% of those requiring spectacles had an adequate correction. A total of 25.3% (n = 24) could be classified as visually impaired. Onward referral for treatable ocular pathology was recommended in 5.3% (n = 5) of patients and 11.6% (n = 11) benefited from assessment by a rehabilitation worker. Experience suggests that with the use of appropriate preparatory material, 86.9% can undertake a complete eye examination. The results of the assessment need to be made available in an easy-to-understand format to the individual and to those involved in their care, so that recommendations can be implemented. Conclusion: Key elements to a successful eye examination with adults who have learning disabilities are utilising a multi-professional approach, preparing patients beforehand, carrying out assessments in a familiar environment and ensuring the outcomes are communicated effectively.
