Assessment Of Visual Impairment Research Articles

Assessment of visual impairment and need of rehabilitation services for children attending schools for blind in an urban city of North India

ABSTRACT Background/Aims: By understanding the prevalence and causes of childhood blindness, stakeholders can work toward comprehensive strategies that encompass prevention, treatment, rehabilitation, and support, ultimately improving the quality of life for affected children. The information about the pattern and causes of childhood blindness in Northern Indian states is limited, it highlights the need for further research and data collection to better understand and address the specific challenges in this region. Therefore, the present cross-sectional study was planned to ascertain the different causes and patterns of childhood blindness and to understand the barriers to the use of LVAs and its compliance among the students attending schools for the blind in a North Indian State. Study Design and Setting: Students from two schools for blind were examined in Chandigarh and its vicinity in North India. The different causes of severe visual impairment/blindness were classified as per the World Health Organization/Prevention of Blindness standard recording form. Results: A total of 89 students attending schools for the blind were examined. The mean age was 13.10 years (range = 4–16 years). Male, female ratio was 3.3:1. The major causes of blindness were congenital anomalies (whole globe anomalies 37.08%), followed by retinal conditions (16.7 = 8%), undetermined/other (12.3), and lenticular conditions (112%). More than one-third of children (34.8%) were blind due to avoidable causes of blindness. Conclusion: The current study data append on the existing national available data about childhood blindness in India. Though the sample size of the current is comparatively low, observed different results as compared to previously published reports from other regions, emphasize the strengthening of pediatric ophthalmology services as well as of low vision services in this particular region of North India.

Corneal High-Order Aberrations in Fuchs Endothelial Corneal Dystrophy and Subclinical Corneal Edema.

High-order aberrations (HOAs) are known to be increased in corneas with Fuchs endothelial dystrophy (FECD) and are associated with visual impairment. This case series aimed to analyze whether tomographic changes in FECD affect the HOA in the early period of the disease. In this retrospective single-center case series, 144 eyes of 85 patients were included, of which 78 eyes of 47 patients with FECD with slit-lamp biomicroscopically visible guttae but no visible corneal edema served as the study-cohort. According to Sun et al, included eyes were divided into 2 groups: group 0 (n = 28; no subclinical corneal edema) and group 1 (n = 50; subclinical corneal edema). A total of 66 healthy eyes of 38 patients served as control group. Mean values and standard deviations were calculated for the root mean square (RMS), coma, trefoil and spherical aberrations (SA) of the cornea (C), the anterior surface (CF), and the posterior surface (CB). Statistically significant differences (P < 0.001) in the RMS HOA (group 0: 0.209 ± 0.044 μm, group 1: 0.372 ± 0.122 μm) and in coma (group 0: 0.082 ± 0.054 μm, group 1: 0.214 ± 0.101 μm) and SA (group 0: -0.130 ± 0.038 μm, group 1: -0.176 ± 0.074 μm) of the CB were found in eyes in group 1 versus those in group 0. There were no statistically significant differences in HOA between the control group and eyes in group 0. FECD eyes with subclinical corneal edema demonstrated significant increase in RMS, coma, and SA of the CB. Tomographic analysis, therefore, helps in visual impairment assessment, disease progression, and decision-making for early endothelial keratoplasty in patients with FECD.

Delving Into the Visual System in the AMA Guides, Fifth Edition

Abstract The assessment of visual impairment using the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Fifth Edition, requires a thoughtful ophthalmologic evaluation and careful application of the functional vision tests and arithmetic criteria provided in Chapter 12, The Visual System, and other chapters, as applicable. The interpolation of the multiple dimensions of the visual system into the enumeration of a single impairment percentage may involve complex mathematical manipulations. Properly enumerated, the value can be utilized rigorously in impairment evaluations, functional evaluations, and even for academic research.

A STUDY TO ASSESS THE CONTRAST SENSITIVITY OF THE HUMAN VISUAL SYSTEM IN PATIENTS WITH OR WITHOUT DIABETES IN A TERTIARY CARE HOSPITAL

Objective: The objective of our study was to assess the variations in contrast sensitivity values of normoglycemic subjects and that of type II diabetic subjects of the same age group. It was also aimed at finding the visual acuities and study the associations of it with contrast sensitivity if any.&#x0D; Methods: It was a hospital-based comparative cross-sectional descriptive study conducted in the out-patient department of the Department of Ophthalmology, Saveetha Medical College, Hospital, Chennai. Visual Acuity and Contrast Sensitivity of 50 Type II Diabetic individuals and 50 age-equivalent control group subjects were measured using the Snellen’s chart and Pelli-Robson chart, respectively, during the months of January to March 2020.&#x0D; Results: Contrast Sensitivity measurements from 50 subjects with Non-Insulin dependent Diabetes Mellitus (NIDDM) were obtained. The subjects were the ones who had minimal or no diabetic retinopathy. It was observed that there is a significant association between reduced contrast sensitivity and Diabetes (P value&lt;.00008). We also noted that CS may be reduced without corresponding loss of Visual Acuity. Hence, both visual acuity and contrast sensitivity measurements are helpful in the assessment of visual impairment due to diabetic eye disease.&#x0D; Conclusion: The contrast sensitivity can be seen as an early marker for visual impairment in diabetic eye care.

Qualitative assessment of visual impairment in patients with age-related macular degeneration using standardized, image-based questionnaires

The purpose of the study is to test a simple approach for characterizing subjective perception in patients with choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD). This multi-center study was performed in four private ophthalmology practices including 20 patients with CNV. Subjects were presented the original image on the affected eye and afterwards modified candidate images to the contralateral eye. Then they chose one image that most closely matched the perception on the affected eye. This was repeated with three different images representing three everyday life scenes manipulated to mimic visual perception with reduced color perception (image 1), central scotomas (image 2), and blurring with four varying sizes (image 3). The frequency of response to the forced choice questionnaire experiment for each image was recorded. Our results show that images manipulated using a Gaussian blur filter, a brightness filter, and a sinusoidal distortion filter were selected by 9, 10, and 1 patients, respectively. Size of modification was not associated with visual acuity in image 1 or image 3. In image 2, however, the size of the modification was dependent on visual acuity ( p = .01). In conclusion, subjective perception in patients with AMD may significantly differ between individual patients. A better understanding of the visual disturbance will facilitate communication and involvement of patients in treatment decisions.

Driving and visual deficits in stroke patients

The aim of the present study was to conduct an exploratory assessment of visual impairment following stroke, and to discuss the possibilities of reintroducing patients to the activity of driving. The Useful Field of View test was used to assess visual processing and visual attention. A total of 18 patients were included in the study, and were assigned to either the drive group (n = 9) or the intention group (n = 9). In the drive group, one patient was categorized as moderate-to-high risk; whereas, in the intention group, one patient was categorized as low-to-moderate risk. Additionally, two patients in the intention group were categorized as high risk. The patients did not perceive their visual deficits as a limitation. Visual attention is an interference factor in terms of the safe performance of driving after a stroke. All patients showed a high level of interest for the independence provided through being able to drive.

Effects of Binocular Acuity in Visual Impairment Assessment

Effects of Binocular Acuity in Visual Impairment Assessment

Assessment of visual impairment: The relationship between self-reported vision and ‘gold-standard’ measured visual acuity

Self-report assessments of health are commonly favoured indicators used in large-scale nationally, representative surveys as they can be readily and cost-effectively collected from large numbers of people; however, subjective assessments have been criticised. Using data from the Irish Longitudinal Study on Ageing (TILDA), this article examines the relationship between self-reported vision and measured visual acuity (Logarithm of the Minimal Angle of Resolution [logMAR]). The analysis indicates that normal vision is well captured by a subjective response, but there is a slight over-identification of visual impairment using self-reported vision. These findings are discussed in relation to social patterning of misreporting. Given the simplicity of the self-report assessment to administer and the correspondence between this and measured visual acuity, it is argued to be a suitable indicator of visual impairment in older people.

Assessment of visual impairment in stroke survivors.

A novel, tablet-based application (app) has been developed to act as a screening tool for visual impairment in stroke survivors; The Stroke Vision app. The app includes assessments for visual acuity, visual fields and visuospatial neglect, as well as novel tools for the education of patients, carers and staff. The app has been devised by experts in the field to address two important deficiencies; firstly a set of visual assessment tools to support and improve evaluation and rehabilitation of visual impairments in stroke survivors, and secondly to provide education for staff and information to carers about their relatives visual disabilities.

Comparison of Patient Preference for Two Insulin Injection Pen Devices in Relation to Patient Dexterity Skills

Impaired dexterity has been reported to be prevalent in diabetes patients independent from the existence of diabetic neuropathy. This study was performed to investigate the impact of dexterity impairment on patient preference for two insulin pen injection devices (InnoLet and FlexTouch). Ninety patients [54 male/36 female; age (mean ± standard deviation), 62 ± 8 years; disease duration, 18 ± 11 years; hemoglobin A1c, 7.2 ± 1.0%] were included in this investigation and were stratified into four different groups based on the results of a dexterity test (Jebsen-Taylor Hand Function Test) and assessment of visual impairment: 15 type 1 (group A) and 30 type 2 (group B) patients with impaired dexterity, 30 type 1/type 2 patients with visual impairment (group C), and 15 type 1/type 2 patients without any impairment (group D). The patients performed a cognitive function test (number connection test), were introduced to the devices in random order, and were asked to perform some mock injections before completing a six-item standardized preference questionnaire. There was a strong preference for FlexTouch in all groups. All unimpaired patients (100%, group D) preferred FlexTouch, as did the vast majority in all other groups. Only 11% of the patients with impaired cognitive function preferred InnoLet, as did a few patients with more severely impaired dexterity or with visual impairment (group A, 13%; group B, 3%; group C, 14%). Patient dexterity skills may have an influence on device preference, especially if the impairment is more pronounced.

Impact of Visual Impairment Assessment on Functional Recovery in Stroke Patients: a Pilot Randomized Controlled Trial

Aim: To determine whether providing therapy staff with objective information regarding the nature of visual impairment enhances functional recovery of stroke survivors. Methods: A mixed methodology incorporated a pilot randomized controlled trial (RCT) and qualitative study. Patients presenting acutely with functional disability and suspected visual deficit, underwent visual assessment. Patients with visual impairment were recruited; all subjects received rehabilitation. The sample was randomized to group A (control) where details of visual assessment were withheld from therapy staff and group B (experimental) where details of visual assessment were disclosed. Functional measures (Functional Independent Measure, timed walk) were recorded at baseline and 6-week follow-up. Health professionals participated in a focus group to discuss the perceived influence of the additional visual assessment service on functional outcome. Findings: 64 patients were recruited over 18 months (group A=31; group B=33). Drop out resulted in 19 subjects in group A and 20 in group B for full analysis. Significant functional improvement was noted in both groups, no significant difference was found between groups. Health professionals reported a perceived positive impact from the vision assessment service. Conclusions: Provision of visual assessment information did not influence functional recovery. Qualitative findings indicated perceived benefits from the provision of the vision assessment service.

Rapid Assessment of Visual Impairment Due to Cataract and Cataract Surgical Services in Urban Argentina

Aim: To present results of a rapid assessment on visual impairment due to cataract and on cataract surgical services in the Northwestern districts of Buenos Aires, Argentina. These results will enable health managers to plan effective interventions in this area in line with VISION 2020. Methods: One hundred fifteen clusters of 40 persons of 50 years and older in each cluster (4600 eligible persons) were selected by systematic sampling from the Northwestern districts of Buenos Aires, Argentina. This area consists of 10 districts with a total population of 2,716,573 (2001 census), from whom 4302 persons were examined (coverage 93.5%). The visual acuity was measured with a tumbling E-chart and the lens status with distant direct ophthalmoscopy. Results: Cataract is the major cause of bilateral blindness (54.2%). The age and sex adjusted prevalence of bilateral cataract blindness (presenting VA < 20/400) in people of 50 years and older was 0.5% (95% CI: 0.4–0.8%), an estimated number of 2,985 persons. The cataract surgical coverage at this level was 70% for males and 78% for females. The prevalence of bilateral cataract and VA < 20/200 in persons of 50 years and older was 0.8% (95% CI: 0.6–1.1), an estimated 4,705 persons. In this last group, the surgical coverage was 66% (persons) and 57% (eyes). Of all operated eyes, 10% could not see 20/200. ‘Cannot afford’ (32%), ‘unaware of cataract’ (21%) and ‘contraindication for surgery’ (18%) were mentioned most as reason why surgery had not been done. Conclusion: The cataract problem is getting under control in this area. Coverage indicators are fairly high, and the outcome data better than in other studies. The cataract surgical rate could be raised further by awareness campaigns and by making cataract surgery more affordable.

Refractive errors and visual impairment in 900 adults with intellectual disabilities in the Netherlands.

To collect data on refractive errors and visual impairment in adults with an intellectual disability (ID) in the Netherlands. A randomized sample of 2100 participants was drawn from a base population of 9000 adults with intellectual disabilities in the Netherlands. This article reports on the first 900 participants. All participants underwent a protocol-based on-site ophthalmological assessment carried out by skilled investigators. Co-operation was classified according to the number of tests that could be carried out reliably and was good or excellent in 80% of subjects, average in 13% and poor in 7%. Refraction could be reliably assessed in 505/900 (56%) subjects. There was an increased risk of visual impairment in all subgroups compared to the general Dutch population. Visual acuity (VA) was related to the level of ID, but refractive errors were not. New spectacles were prescribed in 106 cases (12%). Of 374 people in whom both monocular VA and the refractive error of the right eye could be reliably assessed, 153 (41%) had a pretest prescription, 16 (10%) of which we found to be inadequate. Of the 221 participants without a pretest prescription, 41 (19%) benefited from correction. Only 38/84 (45%) subjects aged 50 years or older, who could benefit from correction for near vision, had near spectacles. New correction increased the mean distant VA significantly from 0.44 to 0.65 (p < 0.0005). With some adaptations, visual screening is feasible in a majority of adults with ID. Visual impairment and refractive errors are much more prevalent in adults with ID than in the normal population. Accurate spectacle correction resulted in significant improvement in distant VA.

Vision Impairment Rating and the Fifth Edition: A New Approach Based on Activities of Daily Living

Abstract The assessment of visual impairment has been significantly revised from the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Fourth Edition. The Fifth Edition, Chapter 12, The Visual System, bases ratings on an estimate of the severity of the effects of certain types of visual loss on the ability to perform activities of daily living (ADLs). Permanent visual impairment is defined as a permanent loss of vision that remains after a patient reaches maximal medical improvement in the underlying medical condition. To assess vision loss, physicians must conduct a visual assessment, including the cause, severity, and prognosis of the underlying disorder and the expected or documented effects of the vision loss on the patient's ability to perform ADLs. Tables in Chapter 12 guide the assessment of visual impairment and consider the results of visual acuity testing, acuity-related impairment rating, and associated classifications. Table 12-10, Classification of Impairment of the Visual System and of the Whole Person, uses clinical data to classify the individual in one of six classes associated with a range of whole person impairment. According to the Fifth Edition of the AMA Guides, examining ophthalmologists or optometrists are required to have new visual acuity charts, appropriate visual field testing equipment, and other equipment for testing contrast sensitivity and glare tests as needed.

Methods for the Hong Kong Vision Study: a pilot assessment of visual impairment in adults

Introduction. The Hong Kong Vision Study (HKVS) was a pilot study to collect data on the prevalence of eye diseases and risk factors in Hong Kong using methodology comparable to that developed in America and Australia. Aim. The main goal was: to evaluate the application of the methodology in a different culture and language; and to determine the prevalence and risk factors of eye diseases in order to design a larger study of an ethnic Chinese population. Method. This study was patterned after the Melbourne Visual Impairment Project using the Chinese language in data collection and examinations. Conclusion. Well-designed methodology is transferable to different cultures, languages and continents. Use of similar methodology will enable better comparisons and analyses to be made from population-based data.

A comprehensive assessment of visual impairment in a population of older Americans: the SEE study.

Results. Visual function decreased linearly with age for the acuity, contrast sensitivity, glare, and visual field tests. Stereoacuity remained constant into the mid-70s and declined at an accelerating rate thereafter. Black participants had lower contrast sensitivity, reduced stereoacuity, and worse visual fields, at all ages compared to white participants; however, white participants were more sensitive to glare. The overall prevalence of visual acuity impairment in blacks was 5.6% versus 3.0% for whites, using the traditional United States definition (worse than 20/40 to better than 20/200) and 3.3% for blacks versus 1.6% for whites, using the World Health Organization definition (worse than 20/60 to 20/400). Acuity was correlated moderately with contrast sensitivity, stereoacuity, and visual fields (Spearman rho = 0.50, 0.35, and 0.34, respectively). The correlation between acuity and glare sensitivity was low (rho = 0.12).

Assessment of Visual Impairment in Patients With Alzheimer's Disease

We examined five patients with Alzheimer's disease who complained of poor vision. Two patients had mild Alzheimer's disease; they complained of problems with reading and of "bumping into things," yet both had normal visual acuities. One patient with moderate Alzheimer's disease had abnormal eye movements, visual-evoked potentials, and contrast sensitivity. The other two patients had severe Alzheimer's disease. Despite difficulties in performing the examination, we were able to see moderate impairments in visual acuity and visual fields, as well as marked dyschromatopsia, severe deficits in contrast sensitivity, and markedly abnormal eye movements and visual-evoked potentials.