Olga Overbury

Participation in daily activities and social roles of older adults with visual impairment

Purpose. (1) to document participation in daily activities and social roles of older adults seeking services for visual impairment (VI) and compare it with that of the older population without VI or other disabilities, and (2) to explore correlates of their participation. Methods. The 64 participants (46 women) had an average age of 79.3 years (SD = 5.9 years) and presented various types of VI. Participants were interviewed at home to collect information regarding their visual function (National Eye Institute Visual Function Questionnaire-25), sociodemographic and clinical characteristics, including depressive symptoms (Geriatric Depression Scale), and participation (Assessment of Life Habits/LIFE-H). Each participant was matched with another person without disabilities randomly recruited from the community. Results for the two populations on the Life-H participation domains were compared using t-tests. In the group with VI, general information (independent variables) was examined in relation to participation main scores (dependent variables), followed by multiple linear regression analyses. Results. Participation in daily activities and social roles of participants with VI (mean ± SD (/9) = 6.8 ± 1.0 and 5.6 ± 1.6, respectively) was significantly lower than that of participants without VI (8.1 ± 0.4 and 8.3 ± 0.4) (p < 0.0001). Depressive symptoms and perceived quality of distance vision were the strongest correlates and together explained more than 65% of the variance in the participation scores of the subjects with VI. Conclusions. This study demonstrates the participation restrictions associated with VI and underlines the importance of psychological aspects in participation.

Binocular vision in older people with adventitious visual impairment: sometimes one eye is better than two.

PURPOSE: To determine the effect of adventitious visual impairment (low vision) on monocular and binocular spatial contrast sensitivity of older people.

Ultrasound biomicroscopy of sclerotomy sites: the effect of vitreous shaving around sclerotomy sites during pars plana vitrectomy.

Purpose To study the difference in the amount of vitreous incarceration between conventional pars plana vitrectomy (PPV) and PPV with vitreous shaving around sclerotomy sites. Methods A dynamic in vivo examination using ultrasound biomicroscopy (UBM) was performed on the sclerotomy sites of 22 eyes after PPV. Patients were divided into two groups. In the study group (n = 11), the vitreous was completely shaved from the internal initial sclerotomy by cotton-tip depressed vitrectomy under coaxial illumination. In the control group (n = 11), no vitreous shaving was performed. Results Vitreous incarceration into sclerotomy sites was significantly less in the study group compared with the control group (P <0.001). No difference was seen among the three sclerotomy sites regarding vitreous incarceration within individual eyes. No difference was seen between eyes operated by right- and left-handed surgeons. Conclusions Vitreous shaving of sclerotomy sites using depressed vitrectomy significantly reduces vitreous incarceration. This may reduce the rate of sclerotomy-related complications following PPV in selected cases.

Health-related and subjective quality of life of older adults with visual impairment

Purpose. To document health-related quality of life (HRQOL) and subjective quality of life (SQOL) and explore their correlates in older adults seeking services for visual impairment (VI). Method. A convenience sample of 64 participants (79.3 ± 5.9 years) with VI was interviewed at home. HRQOL was measured with the Visual Function Questionnaire-25 and SQOL with the Quality of Life Index. The potential correlates were as follows: personal factors (sociodemographic characteristics, co-morbidity, depressive symptoms, activity level), environmental factors (technical aids, social support) and participation in daily activities and social roles (level and satisfaction). Results. Compared to normative data from previous studies of older adults, the participants had lower HRQOL but similar SQOL. Greater level of participation in social roles, higher perceived activity level, use of a writing aid and greater satisfaction with participation in social roles together explained better HRQOL (R2 = 0.66). Fewer depressive symptoms, greater satisfaction with participation in social roles and with social support and fewer co-morbidities together explained better SQOL (R2 = 0.70). Conclusions. HRQOL of older adults with VI is mainly explained by level of participation correlates, while their SQOL is mainly explained by depressive symptoms and satisfaction variables. The results also underscore the importance of social roles for HRQOL and SQOL of this population.

Barriers to Low Vision Rehabilitation: The Montreal Barriers Study

PURPOSE One objective of the Montreal Barriers Study was to examine demographic characteristics of people with vision impairment that may hinder their referral or decision to access rehabilitation services. METHODS Data collection was conducted in three phases, whereby during phase I, patients in ophthalmology department waiting rooms underwent a structured interview to ascertain demographic variables that may be related to their utilization of the rehabilitation process. Phase II examined variables recorded in the rehabilitation agency file of those who had made the choice to access services. Phase III examined the rehabilitation access behavior of those participants who were referred as part of phase I. RESULTS In phase I, 54% of the 702 participants had been referred to and received rehabilitation services. An additional 13% were aware of these services but chose not to access them, whereas 33% were unaware of their existence. The variables associated with positive access choice were education, diagnosis, race, acuity at the time of interview, and living situation. In phase II, it was found that acuity at agency intake was markedly better than at the study interview. Of the participants who were referred to rehabilitation services as part of the phase I protocol, it was found in phase III that only 56% had engaged in rehabilitation services. CONCLUSIONS It seems that even under ideal referral situations, there remain barriers to vision rehabilitation services that have not been specifically identified in the present study. Further research is necessary on the psychological and psychosocial contributors to this process.

Visual function assessment and metamorphopsia after macular hole surgery

The purpose of this study was to develop a new resolution acuity measure for patients after macular hole surgery. Fifty eyes of 44 patients who had undergone successful treatment were tested. Visual acuity was measured with the Snellen, Early Treatment of Diabetic Retinopathy Study and Landolt‐C charts. A Line Resolution Test was performed as part of their follow‐up exam where a vertical line was presented. Participants were categorized by their perception of the line as solid, bent or broken. The line could be distorted into a sine‐wave pattern in order to determine the participants’ detection threshold for the distortion. Chart acuities did not differ among the three groups, as categorized by their line perception. Only the distortion measure was sensitive enough to differentiate the solid‐ from the broken‐line group. The distortion measure assesses resolution power of the macula in smaller increments than acuity charts. This hyperacuity approach is more appropriate in the assessment of functional outcome after microsurgery.

Multi-Flash Campimetry as an Indicator of Visual Field Loss in Glaucoma

Multi-flash campimetry is a computer-implemented technique used for the rapid assessment of temporal resolving power across the visual field. On the basis of previous reports that glaucoma patients exhibit impaired temporal sensitivity earlier than conventional perimetric field loss, the question of whether multi-flash campimetry might also be sensitive to the visual consequences of glaucoma was explored. Of the 27 patients that were tested, only one had normal temporal resolving power in both eyes, suggesting that multi-flash campimetry might be a useful aid in determining whether a patient should be diagnosed and treated as a glaucoma suspect or as a confirmed glaucoma patient.

Multi-flash campimetry and other psychophysical tests in chronic open angle glaucoma

Multi-flash campimetry (MFC) is a computer implemented psycho-physical technique which allows sampling of temporal resolution at 120 points of a 40 degree visual field. The technique is rapid (about 20 minutes per eye), reproducible and easy to perform. We compared MFC to Octopus perimetry, colour vision and spatial contrast sensitivity in a series of thirty eyes of 30 observers. Nine were early glaucomatous eyes, 10 were glaucoma suspect eyes and 11 were normal controls.

Defining the nature of motion perception deficits in glaucoma using simple and complex motion stimuli.

Purpose. The purpose of this study is to determine the nature of motion perception deficits in primary open-angle glaucoma by measuring the sensitivity of simple (luminance-defined) and complex (texture-defined) motion, the latter requiring supplementary neural processing to be resolved. These findings will help address the possible extent of the cortical damage in glaucoma that has been recently demonstrated by anatomic and physiological studies. They also serve the purpose of establishing which motion paradigms would be most appropriate for assessing glaucoma-related functional loss. Methods. Direction-identification thresholds for first-order and second-order motion were measured for 26 patients with primary open-angle glaucoma (for both phakic and pseudophakic) and 18 nonglaucomatous observers. Results. The glaucomatous observers showed significantly increased motion thresholds for both first- and second-order motion conditions when compared with nonglaucomatous observers. However, the relative increase in threshold for first-order motion did not differ significantly from that of second-order motion. Conclusions. These findings imply that there is no measurable higher-level cortical function damage caused by the glaucomatous process because no greater loss in second-order motion was observed. Based on the results, we suggest that motion paradigms used to assess functional loss in primary open-angle glaucoma should consist of simple, first-order type stimuli to minimize potential confounds such as those introduced by both the normal and pathologic aging process on complex motion processing (i.e., perimetry using complex motion stimuli).

Active-passive paradigm in assessing CCTV-aided reading.

ABSTRACT Six male and seven female English‐speaking university students, with corrected vision of 20/20 (6/6), were trained using the closed circuit television system (CCTV) as a reading aid. This was an attempt to identify the essential factors in CCTV‐aided reading. Active and passive observers were trained in pairs, with the passive observer being the yoked control of the active observer. The control participants were trained alone using the same reading material without the use of a CCTV. All participants used material from the Thurstone Reading Kit throughout the five training sessions and were given a pre‐ and postreading test to assess the increase in reading speed measured in words per minute (WPM). The active observers increased their reading speed to a greater extent than the passive observers, and the passive observers to a greater extent than the control participants. Suggestions are made pertaining to future experimentation and use of the CCTV.