Visual correlates of mobility in real world settings in older adults with low vision

PURPOSE: To determine the effects of reducing light level from photopic to mesopic on performance of real world mobility tasks and how performance of these tasks relates to measures of visual sensory and perceptual function. METHODS: The visual functions, acuity, peak letter contrast sensitivity, visual field extent, glare disability, color confusion, motion sensitivity, spatio-temporal contrast sensitivity, scanning ability, and figure-ground discrimination were measured to determine their ability to predict mobility performance of visually impaired adults on indoor hallway and outdoor residential travel routes under photopic and mesopic lighting conditions. RESULTS: Time to complete routes and number of mobility incidents were significantly increased under mesopic conditions. Depending on the task, lighting conditions, and performance measure, predictive models consisting of 4 vision variables were able to account for 30 to 42% of the variance in overall performance. The two most important variables in these models were visual field extent and scanning ability, followed by color confusion, grating contrast sensitivity, or spatial resolution. CONCLUSIONS: Reducing illumination levels from photopic to mesopic has an adverse effect upon mobility in older visually impaired adults. The aspects of vision which best predict performance include measures of sensory and perceptual visual function. The results compare well with those obtained under controlled laboratory conditions.     

Difficulty in performing everyday activities in patients with juvenile macular dystrophies: comparison with patients with retinitis pigmentosa

AIMS: To ascertain the level of perceived difficulty experienced by patients with central vision loss due to juvenile macular dystrophies in the performance of everyday activities. A second objective was to compare their perceived difficulty with that of patients with retinitis pigmentosa (RP) with primarily peripheral vision loss. METHODS: 72 patients with Stargardt disease, cone dystrophy, or cone-rod dystrophy who had visual acuities worse than 20/40 and normal peripheral visual fields rated themselves on their difficulty in the performance of 33 activities encompassing a wide variety of everyday tasks. These findings were compared with the responses of 120 patients with typical RP or Usher syndrome type 2 who had visual acuities of 20/40 or better and peripheral visual field loss. RESULTS: The juvenile macular dystrophy group reported the greatest level of overall self perceived difficulty with activities involving central vision, and lesser and variable degrees of difficulty with items within the mobility, negotiating steps, driving, and miscellaneous categories. Consistent with these findings, there were highly significant correlations between subjects' rated performances of activities involving central vision and the clinical measures of vision, including visual acuity and size of central scotoma. There were fewer significant correlations between perceived performance of activities in the other categories and the clinical measures. In general, those activities that showed significant correlations with the clinical measures of vision for the patients with juvenile macular dystrophies also showed significant differences in the patterns of responses between the juvenile macular dystrophy group and the RP group. Those items which were not correlated with the clinical measures in the juvenile macular dystrophy group tended not to show significant differences in the response patterns between the two groups. CONCLUSION: These results provide insight into the types of perceived difficulties in performing tasks of everyday life in patients with these disorders which affect counselling of these patients.     

Mental effort required for walking: effects of retinitis pigmentosa

PURPOSE: To determine whether retinitis pigmentosa (RP) increases the mental effort required for walking. METHODS: A dual-task methodology was used; walking speed and reaction time (RT) to randomly emitted tones were measured in 13 persons with RP and 29 persons with normal vision. Measures of RT were used to estimate the mental effort required for walking. In a second experiment, 15 persons with RP and 17 persons with normal vision navigated a "simple" and a "complex" route. RESULTS: The RP subjects had longer RT compared with the normal-vision subjects when walking the complex but not the simple route. Normalized to each person's baseline, RT while walking the complex route was significantly correlated with log contrast sensitivity (r = -0.63) and log retinal area (r = -0.64) in the RP group. The amount of mental effort required for walking was shown to also depend on familiarity with the route. CONCLUSIONS: Route complexity is critical in determining whether walking requires more mental effort for persons with RP than for persons with normal vision. The magnitude of mental effort required for mobility covaries with the visual impairment measures which correlate with mobility performance in RP.     

Comparison of a functional obstacle course with an index of clinical gait and balance and postural sway

BACKGROUND: Older adults commonly experience falls because of balance and mobility problems. Better assessment methods are needed to understand and correct balance and mobility disorders. METHODS: We used a low technology, functional obstacle course (FOC) to measure balance and mobility in 352 community-dwelling elderly participants. To establish concurrent validity of the FOC, we compared performance on the FOC with two established measures of balance and mobility: performance on the Tinetti Index (TI) and postural sway area measured on a force platform. RESULTS: Bivariate correlation analyses revealed significant inverse correlations between FOC completion time, the TI balance and gait subscores, and the TI total score (r = -.73 to -.78). The FOC quality scores and TI balance and subscores gait and TI total scores (r = .76 to .82) were significantly positively correlated. FOC time had significant, but small, positive correlations with sway area with eyes open (r = .18) and closed (r = .17) and nonsignificant correlation with sway area with visual feedback. FOC quality also had significant, but smaller, inverse correlations with sway area with eyes open (r = -.024) and closed (r = -.015), and nonsignificant correlation with sway area with visual feedback. Regression analysis showed that TI gait and balance measures accounted for most of the variance found in FOC performance. CONCLUSIONS: Our findings support the position that the FOC and the TI measure dynamic balance, whereas postural sway measures a different aspect of balance. Advantages of the FOC include the evaluation of environmentally influenced falls and balance problems.     

Interrelationships among biological markers of aging, health, activity, acculturation, and cognitive performance in late adulthood.

In this study a structural equation model of predictors of age differences in cognitive performance in late adulthood was developed. Biological markers of aging (vision, hearing, vibration sense, forced expiratory volume, and grip strength) were used as indicators of a latent variable called BioAge. A sample of 180 community-dwelling women aged 60 to 90 years was assessed. Results showed that BioAge explained all of the age-related variance in cognitive test performance. Physical health and physical activity had direct effects on BioAge. Measures of acculturation explained non-age-related variance in cognitive test performance. Some variables used as biomarkers also explained individual differences in measures of crystallized intelligence and perceptual speed. It is concluded that the association between biomarkers and cognition in old age is due to more than a common statistical association with age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The impact of disaster support work

Limited available evidence suggests that disaster support work may have negative effects. This study attempts to examine the impact of disaster-related stress on helpers offering psychological support to victims of two major disasters, and to identify potential moderating factors. Sixty-seven social workers were surveyed, measures being taken of psychological symptomatology and wellbeing, personality variables, social support, life events, and various aspects of disaster support work. Comparison with normative data suggested that subjects were experiencing significant levels of stress. Two major sources of disaster-related stress were identified: role-related difficulties and contact with clients' distress. Approximately one third of the variance in helper response could be explained by variables reflecting coping style, prior life events and the aforementioned aspects of disaster support work. Follow-up data at 12 months demonstrated persisting high levels of stress.     

Improvements in clinical and functional vision and perceived visual disability after first and second eye cataract surgery

AIMS: To determine the improvements in clinical and functional vision and perceived visual disability after first and second eye cataract surgery. METHODS: Clinical vision (monocular and binocular high and low contrast visual acuity, contrast sensitivity, and disability glare), functional vision (face identity and expression recognition, reading speed, word acuity, and mobility orientation), and perceived visual disability (Activities of Daily Vision Scale) were measured in 25 subjects before and after uncomplicated cataract surgery (10 first eye surgery and 15 second eye surgery) and in 10 age matched controls. RESULTS: Significant improvements were found after surgery in clinical and functional vision and perceived visual disability. Greater improvements were found after first eye surgery than after second eye surgery. However, first eye surgery did not return all scores to age matched normal levels. There were significant improvements in several of the tests measured after second eye surgery, and all postoperative values were similar to those from age matched normals. CONCLUSIONS: Significant improvements in clinical, functional, and perceived vision are obtained by cataract surgery. The improvements in objective measures of functional vision found in this study support previous findings of improvements in patients' perceived functional vision. In addition, these data provide support to the necessity of second eye surgery in some patients to improve certain aspects of visual function to age matched normal levels.     

Visual scanning of faces correlates with schizophrenia symptomatology

1. The purpose of this study was to examine whether quantitative measures of visual scanning of faces correlated with the severity of symptoms in patients with schizophrenia. 2. Preattentive visual fixations (fixations less than or equal to 50.1 ms in duration) were measured while 16 subjects with chronic schizophrenia and 38 comparison subjects scanned slides of human faces. 3. A significant inverse correlation was found between the number of preattentive fixations exhibited during 10 seconds of facial scanning and total Brief Psychiatric Rating Scale (BPRS) scores. 4. This study suggests that measures that probe preattentive processing during scanning of faces could represent a novel paradigm for studying the symptoms of schizophrenia.     

Group treatment of depression: Individual predictors of outcome.

The present study attempted to identify patient characteristics predictive of individual outcome in a psychoeducational group treatment for unipolar depression. Forty participants meeting Research Diagnostic Criteria for depressive disorders were assessed on demographic and psychological variables at both pre- and posttreatment and on participation variables during treatment. The treatment modality was the Coping With Depression Course. At the end of treatment, 85% of the subjects no longer met diagnostic criteria for depressive disorders. A stepwise multiple regression analysis attained a multiple correlation of .92, accounting for 85% of the variance in posttreatment depression level. Ten variables accounted for significant portions of the outcome variance beyond that explained by pretreatment Beck Depression Inventory scores. The results of previous studies were partially replicated; predictive ability was improved markedly over prior reports. The results suggest that the most robust predictors of outcome are pretreatment levels of depression, social functioning, perceived mastery over events, and early positive perceptions of group cohesiveness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Strength in the lower limbs, visual contrast sensitivity, and simple reaction time predict cognition in older women.

The authors investigated the association between sensorimotor variables indicative of biological aging and cognition. A community sample of 202 women ages 60–86 was assessed on 5 measures of lower limb strength, visual contrast sensitivity (VCS), and reaction time (RT). Hierarchical multiple regression revealed that the sensorimotor variables explained age-related variance in measures of reasoning and total variance in measures of reasoning after education, health, mood, and physical activity were controlled for. It is concluded that in addition to better known predictors of cognitive aging, such as RT and VCS, lower limb strength is an important predictor of performance on cognitive tests. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Blindsight and visual awareness

Some patients with damaged striate cortex have blindsight-the ability to discriminate unseen stimuli in their clinically blind visual field defects when forced-choice procedures are used. Blindsight implies a sharp dissociation between visual performance and visual awareness, but signal detection theory indicates that it might be indistinguishable from the behavior of normal subjects near the lower limit of conscious vision, where the dissociations could arise trivially from using different response criteria during clinical and forced-choice tests. We tested the latter possibility with a hemianopic subject during yes-no and forced-choice detection of static and moving targets. His response criterion differed significantly between yes-no and forced-choice responding, and the difference was sufficient to produce a blindsight-like dissociation with bias-sensitive measures of performance. When measured independently of bias, his sensitivity to static targets was greater in the forced-choice than in the yes-no task (unlike normal control subjects), but his sensitivity to moving targets did not differ. Differences in response criterion could therefore account for dissociations between yes-no and forced-choice detection of motion, but not of static pattern. The results explain why patients with blindsight are apparently more often "aware" of moving stimuli than of static stimuli. However, they also imply that blindsight is unlike normal vision near threshold, and that pattern- and motion-detection in blindsight may depend on different sets of neural mechanisms during yes-no and forced-choice tests.     

Relating body image to psychological and sexual functioning in child sexual abuse survivors

Cognitive-affective body image variables and their relation to long-term psychological and sexual functioning were investigated in a community sample of 57 female adult child sexual abuse (CSA) survivors and 47 comparison subjects. The Body-Self Relations Questionnaire and the Body Esteem Scale were administered to assess cognitive-affective body image. Group comparisons indicated that, after controlling for actual weight status, survivors evaluated their health more negatively and reported less body esteem regarding their sexual attractiveness than comparison subjects. Body image variables related to health and sexual attractiveness significantly explained variance on symptom measures that reflect the diverse CSA long-term sequelae. Results suggest the need for careful assessment of body image disturbances and the development of effective interventions targeting body image in the treatment of CSA survivors.     

Yearly rates of rod and cone functional loss in retinitis pigmentosa and cone-rod dystrophy

OBJECTIVE: To provide the first measures of the relative rates of rod and cone functional loss in patients with retinitis pigmentosa (RP) or cone-rod dystrophy (CRD). DESIGN: Five-year, prospective natural history study. PARTICIPANTS: Ninety-six patients (67 with RP and 29 with CRD) retaining measurable rod-mediated visual function and 5 normal subjects were tested at baseline and annually for 4 consecutive years. MAIN OUTCOME MEASURES: Tests of visual function included visual acuity, dark-adaptation thresholds, dark-adapted static perimetry, and rod and cone computer-averaged electroretinograms (ERGs), which were obtained over a range of retinal illuminances. Intervisit variability for each measure was obtained in a subset of patients who were tested twice within a 2-month interval and was used to determine whether an individual patient had shown progression, regression, or no change over a particular study interval. RESULTS: Over a 4-year interval, a significant number of patients with RP (60%) and CRD (62%) showed a decline in cone ERG amplitude. For rod ERG amplitude, the percentage of patients with RP or CRD showing progression was 64% and 45%, respectively. Although visual acuity, dark-adapted threshold, and rod visual field area also declined significantly over the 4-year period, the mean rate of change and the numbers of patients showing progression on these measures were lower than those for ERG measures. On specialized ERG testing, the yearly change in rod ERG threshold in RP was greater than the yearly change in cone ERG threshold, and the rate of progression varied significantly among inheritance types. For patients with CRD, the yearly change in rod threshold was comparable to the yearly change in cone ERG threshold. CONCLUSIONS: This study helps to define the natural progression of rod-mediated and cone-mediated functional loss in patients with RP and CRD.     

Autosomal-dominant retinitis pigmentosa associated with an Arg-135-Trp point mutation of the rhodopsin gene. Clinical features and longitudinal observations

PURPOSE: To report the clinical and functional characteristics of patients affected with autosomal-dominant transmitted retinitis pigmentosa (adRP) from a large Italian pedigree in which a point mutation predicting the Arg-135-Trp change of rhodopsin was identified by polymerase chain reaction-single-strand conformation polymorphism analysis. METHODS: Seven patients, ranging in age from 6 to 41 years, underwent a full clinical ophthalmologic evaluation, kinetic visual field testing, and electroretinographic testing. RESULTS: In agreement with previous reports, this rhodopsin mutation yielded a particularly severe phenotype, both clinically and functionally. The evaluation of patients from this pedigree in the first and second decade of life demonstrated that retinal function is still electroretinographically measurable at least until 18 years of age, although reduced to 2% to 4% of normal. Longitudinal measures showed that the rate of progression of the disease was unusually high, with an average 50% loss per year of electroretinographic amplitude and visual field area with respect to baseline. Later in the course of the disease, macular function is also severely compromised, leaving only residual central vision by the fourth decade of life. CONCLUSIONS: The phenotype associated with mutations in codon 135 of the rhodopsin molecule appears to have an unusually high progression rate and yields an extremely poor prognosis. These distinctive features make the Arg-135-Trp phenotype substantially different from the general RP population, and also from many of the other adRP pedigrees with known rhodopsin mutations reported to date.     

Patterns of visual field progression in patients with retinitis pigmentosa

OBJECTIVE: The purpose of the study was to determine whether distinct patterns of visual field progression are present in patients with retinitis pigmentosa (RP) and to evaluate the correlation between these patterns, if present, and different genetic subtypes of RP. DESIGN: A retrospective analysis of patterns of visual field progression in RP was performed. PARTICIPANTS: Visual fields of 162 patients with RP, including 55 with type 2 Usher syndrome, who had at least 3 Goldmann visual field examinations during a period of at least 3 years were reviewed. MAIN OUTCOME MEASURES: Goldmann visual fields. RESULTS: Visual fields of 86 patients could be classified into one of three specific patterns of visual field progression. Pattern I included those patients with a progressive concentric loss of visual fields; pattern II included those with visual field loss that began superiorly and subsequently developed an arcuate scotoma that progressed either from the nasal (IIA) or the temporal (IIB and IIC) side; and pattern III included patients whose visual field loss was characterized initially by a complete or incomplete midperipheral "ring scotoma" that broke through into the periphery. The end stage of all these patterns was a residual central visual field, sometimes also associated with a small peripheral island. In 53 of the 162 patients, the pattern of visual field loss could not be categorized because of an advanced stage of field loss at the time of the initial examination. CONCLUSIONS: Distinctive patterns of visual field progression can be observed in patients with retinitis pigmentosa and type 2 Usher syndrome. There were no intrafamilial variations in the pattern of visual field loss in our data on 24 patients from 11 families. Within certain genetic subtypes, there was a predilection for a preponderance of a specific pattern of visual field progression. Future studies may be able to correlate these patterns of visual field loss with different genetic mutations. A greater understanding as to why certain patterns of field loss exist could potentially provide greater insight into the various pathogenetic mechanism(s) by which photoreceptor cells degenerate in this group of patients.     

A contextual cognitive-behavioral analysis of rehabilitation workers' health and well-being: Influences of acceptance, mindfulness, and values-based action.

Purpose: Rehabilitation settings can be extremely demanding, and sometimes stressful, places to work. It is important, therefore, to consider influences on rehabilitation workers' health and general well-being and on their ability to face emotional, physical, or mental challenges at work. The purpose of this study was to examine a set of psychological processes, including psychological acceptance, mindfulness, and values-based action, that may be relevant to this problem. Method: Ninety-eight rehabilitation workers at the Rehabilitation Centre, Tan Tock Seng Hospital, Singapore, completed measures of background variables, health, and functioning, in addition to the 3 psychological variables of primary interest. Results: Correlation analyses demonstrated significant relations of the acceptance, mindfulness, and values measures with the measures of stress, burnout symptoms, health, and well-being, particularly general health perception, vitality, social functioning, and emotional functioning. In regression analyses, the process variables accounted for significant, and in some cases practically meaningful, increments in explained variance in 10 key outcomes related to work experience and health. Conclusion: Acceptance, mindfulness, and values-based action deserve further consideration in relation to burnout, health, and well-being among rehabilitation workers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognition-based and affect-based trust as mediators of leader behavior influences on team performance.

We develop a model in which cognitive and affective trust in the leader mediate the relationship between leader behavior and team psychological states that, in turn, drive team performance. The model is tested on a sample of 191 financial services teams in Hong Kong and the U.S. Servant leadership influenced team performance through affect-based trust and team psychological safety. Transformational leadership influenced team performance indirectly through cognition-based trust. Cognition-based trust directly influenced team potency and indirectly (through affect-based trust) influenced team psychological safety. The effects of leader behavior on team performance were fully mediated through the trust in leader variables and the team psychological states. Servant leadership explained an additional 10% of the variance in team performance beyond the effect of transformational leadership. We discuss implications of these results for research on the relationship between leader behavior and team performance, and for efforts to enhance leader development by combining knowledge from different leadership theories. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Increased risk of autoimmune hypothyroidism in patients affected by retinitis pigmentosa

Patients with Retinitis Pigmentosa (RP) show hemeralopia, restricted field of vision and reduced visual acuity, owing to the degeneration and proliferation of photoreceptors and a retinal pigment epithelium. The prevalence in Italy is 1:4,000. A certain number of "syndromic" associations have been described, and, in particular, also that with hypothyroidism, but very few cases have been studied. We describe a family of 40 people, spanning four generations, in which we have recorded the presence of autosomic dominant RP, associated with autoimmune hypothyroidism or with circulating antithyroid autoantibodies (ATA), currently considered as the expression of active autoimmune thyroiditis or a risk factor for this complaint. We measured, in all members, TSH, FT3, FT4, antithyroglobulin and antithyroperoxidase autoantibodies. A fundus oculi examination was performed in every subject, as well as a careful examine of the anterior region on the neck. A control population of 100 healthy people was also studied. Our data show a higher prevalence of ATA, statistically significant, in the patients with RP and in their relatives, compared with the control population and the data from the literature (13 cases over 40 = 32.5%; p < 0.01). 3 patients with RP and ATA were affected by clinically evident hypothyroidism. 10 patients with ATA were clinically euthyroid; 8 patients affected by RP did not show circulating ATA at the time of the study. The interest for the physician in this "syndromic" retinal distrophy reflects the need, emerging from our data, to test the thyroid function in the subjects with RP and in members of their families, since circulating ATA are considered a risk factor for the development of autoimmune hypothyroidism.     

Touch relieves stress and pain

The contribution of non-biomedical factors to the experience of pain in the cancer patient has not been well established. Although intensity of pain reports cannot be fully explained by extent of identifiable nociception or neuropathy, behavioral factors have been only modest predictors of cancer pain report. Most studies that have demonstrated associations between pain and behavioral factors were conducted with highly selected groups of patients with all data collected concurrently. Thus the predictive value of the behavioral factors has been indeterminable. In this study, 358 bone marrow transplant patients (196 male, 162 female) completed pretransplant biomedical, physical functioning, psychological and social evaluations. For 25 days following transplantation, patients completed daily visual analogue scale oral pain reports and nurses recorded opioid use. At least once a week oral medicine staff completed a standardized, validated measure of observable oral mucositis as a measure of nociception. Results indicated that psychological and social variables were significant predictors of pain in this sample. Distress, particularly distress specific to the transplant, was the strongest predictor, while self-efficacy and coping style were weaker, but significantly associated with pain report for either men or women. While the psychological and social variables were significant predictors of pain, most of the variance in pain report was explained by biomedical variables rather than psychological or social variables. These results are consistent with those of previous research and indicate that biopsychosocial associations predate the onset of pain, but are at best modest predictors of cancer patients who will report greater or lesser pain. Clinical applications and limits of these data are discussed, particularly in relation to emotional distress, coping style and the differences found in predicting pain in men and women.