Gwyn Rees

Social and emotional impact of diabetic retinopathy: a review

People with vision‐threatening diabetic retinopathy are likely to experience enhanced social and emotional strain. Critically, those with both vision‐threatening diabetic retinopathy and psychosocial problems may have significantly reduced levels of functioning compared with psychologically healthy counterparts. This can cause inadequate compliance, increased strain on family functioning, worse diabetes control, increased progression of diabetic retinopathy and, consequently, further psychosocial stress resulting in a number of concerning implications for disease management, clinical outcomes and healthcare costs. However, the emotional and social health consequences of diabetic retinopathy have not yet been systematically explored. This information is crucial as it allows for a targeted approach to treatment and prevention and avoidance of the potentially detrimental implications described above. Therefore, this paper reviews the current qualitative and quantitative evidence regarding the social and emotional impact of diabetic retinopathy and identifies directions for future research. Key search terms were applied to the electronic databases Pubmed, ISI Web of Science and Embase and the bibliographies of relevant papers were systematically reviewed for additional references. Overall, the evidence suggests that diabetic retinopathy and associated vision loss have several debilitating effects, including disruption of family functioning, relationships and roles; increased social isolation and dependence; and deterioration of work prospects resulting in increased financial strain. Adverse emotional responses include fear, anxiety, vulnerability, guilt, loss of confidence, anger, stress and self‐perception issues. However, the research to date is largely qualitative in nature, with most quantitative studies being small, cross‐sectional and somewhat outdated. Similarly, the outcome measures used in many studies to date are suboptimal in terms of content and validity. Therefore, this review identifies the need for improved outcome measures to provide valid, meaningful measurement of the social and emotional impact of diabetic retinopathy and discusses potential directions for future research such as item banking and computer adaptive testing.

Assessing Participation in Daily Living and the Effectiveness of Rehabiliation in Age Related Macular Degeneration Patients Using the Impact of Vision Impairment Scale

Purpose: To assess if the Impact of Vision Impairment (IVI) is a valid instrument to measure participation in daily activities and rehabilitation in patients with age-related macular degeneration (AMD) and varying levels of visual impairment. Methods: Participants, recruited from a public eye hospital and low vision centers, completed the IVI questionnaire. The IVI and its three subscales were assessed for fit to the Rasch model. Unidimensionality, item fit, response category performance, and targeting of items to patients were assessed. Confirmatory factor analysis (CFA) was used to assess the three-factor model of the IVI in this sample of AMD patients. Results: 219 patients (mean ± SD age = 83.5 ± 7.4 yr) were recruited. Of these, 22%, 55% and 23% had mild (< 6/12–6/18), moderate (< 6/18–6/60) and severe (< 6/60) vision loss, respectively. The IVI total and three subscales displayed discrete thresholds indicating that the respondents understood the response categories. The IVI items fitted the scale and unidimensionality was established. Person separation reliability for the IVI score was substantial (0.94) indicating that the scale can discriminate between several groups of AMD patients. The IVI items were significantly targeted to the AMD patients with the means of the two distributions shown to be very close (0.0 and 0.1, respectively). Substantial targeting was also evident for the subscales. Poorer visual acuity was significantly associated (ANOVA; F (2, 216) = 23.4; p < 0.001) with greater restriction of participation suggesting that the IVI has substantial construct validity. CFA supported the IVI three-factor model which includes items from the “emotional well-being, “reading and accessing information” and “mobility and independence” subscales. Conclusions: Clinicians and researchers can reliably use the IVI to assess the impact on daily life and the effectiveness of clinical trials and rehabilitation interventions in patients with AMD across a range of vision loss.

An Evaluation of the 10-item Vision Core Measure 1 (VCM1) Scale (the Core Module of the Vision-Related Quality of Life scale) Using Rasch Analysis

Purpose: To assess and re-engineer the Vision Core Measure 1 (VCM1) questionnaire in low vision (LV) and cataract participants using Rasch analysis. Methods: 295 participants drawn from a low vision clinic and 181 from a cataract surgery waiting list completed the 10-item VCM1. Unidimensionality, item fit to the model, response category performance, differential item functioning (DIF) and targeting of items to patients were assessed. Category collapsing and item removal were considered to improve the questionnaire. Results: The initial fit of the VCM1 (combined populations) to the Rasch model showed lack of fit (χ 2 = 83.3, df = 50, p = 0.002). There was evidence of DIF between the two populations which could not be resolved. Consequently, each population was assessed separately. Irrespective of the population, disordering of response category thresholds was evident. However, collapsing categories produced ordered thresholds and resulted in fit to the Rasch model for the LV (Total χ 2 = 41.6, df = 30; p = 0.08) and cataract population (Total χ 2 = 17.9, df = 20, p = 0.59). Overall, the VCM1 behaved as a unidimensional scale for each population and no item showed evidence of DIF. Item targeting to patients was however sub-optimal particularly for the cataract population. Conclusion: The VCM1 questionnaire could be improved by shortening the response scale, although different response categories are required for cataract and LV populations. Calibration of items also differed across populations. While the VCM1 performs well within the Rasch model, in line with its initial purpose, it requires the addition of items to satisfactorily target low vision and cataract populations.

Methodology and early findings of the Diabetes Management Project: a cohort study investigating the barriers to optimal diabetes care in diabetic patients with and without diabetic retinopathy

Background:  The Diabetes Management Project is investigating the clinical, behavioural and psychosocial barriers to optimal diabetes care in individuals with and without diabetic retinopathy.

Validity of a visual impairment questionnaire in measuring cataract surgery outcomes

PURPOSE: To test the validity of the Impact of Visual Impairment (IVI) questionnaire in a cataract population. SETTING: Flinders Eye Centre, Flinders Medical Centre, Flinders University, Adelaide, South Australia. METHODS: Cataract patients recruited from a hospital waiting list completed the IVI questionnaire. The scale was assessed for fit to the Rasch model. Unidimensionality, item and person fit to the model, response category performance, differential item functioning (whether different subgroups responded differently), and targeting of item difficulty to patient ability were assessed. RESULTS: Overall, the IVI questionnaire performed well; there were ordered thresholds, person separation reliability was 0.97, and it was free from differential item functioning. One item (worry about eyesight getting worse) misfit the model and was removed. There was evidence of multidimensionality, indicating that the overall IVI score should be discarded; however, the 3 subscales (reading and accessing information, mobility and independence, and emotional well‐being) functioned well. Several items calibrated differently in cataract patients compared with low‐vision patients, indicating different issues are important to each population and that there is a need for population‐specific conversion algorithms. Targeting of the IVI items was biased toward more impaired patients. CONCLUSIONS: The 3 subscales of the IVI questionnaire functioned well in a cataract population. However, additional items targeting the less impaired patients, especially second‐eye cataract patients, would improve measurement.

Impact of early and late age-related macular degeneration on vision-specific functioning

Aim To assess the impact of early and late age-related macular degeneration (AMD) on vision-specific functioning in Singapore Malays. Methods AMD was assessed from fundus photographs. The following endpoints were considered for (a) AMD: no AMD, early AMD, and late AMD; (b) drusen: absence and presence; and (c) retinal pigment epithelium (RPE) abnormality: absence and presence. Vision functioning was assessed using the modified VF-11 scale validated using the Rasch analysis. The overall functioning score was used as the main outcome measure. Results Retinal photographs and vision functioning data were available only for 3252 participants. After age standardisation, the prevalence of early AMD was 3.5% and late AMD 0.34%. In multivariate models, after adjusting for age, gender, education, level of income, smoking status, ocular condition and hypertension, only late AMD was independently associated with poorer vision functioning when compared with no AMD or early AMD (β (β regression coefficient)=−6.4 (CI −11.7 to −2.1; p=0.01)). Early AMD or its principal components, drusen or RPE abnormality, were not independently associated with vision functioning (p>0.05). In adjusted multinomial logistic regression models, people with late AMD were twice as likely (OR=2.23; 95% CI 1.16 to 7.11) to have low overall functioning than those without AMD. Conclusions Late AMD has a significant impact on visual functioning, but early AMD, drusen and RPE changes have no impact. These data highlight the importance of preventive public health strategies targeting patients with early AMD signs in order to prevent progression to late AMD when visual function is compromised.

Impact of diabetic retinopathy on patients' beliefs about diabetes

Background:  The aim was to compare beliefs about diabetes and determine their associations with psychological well‐being, self‐management behaviour and glycaemic control in those with and without diabetic retinopathy (DR).

What is the best measure for assessing diabetes distress? A comparison of the problem areas in diabetes and diabetes distress scale: results from Diabetes MILES-Australia

This study used Rasch analysis to examine the psychometric validity of the Diabetes Distress Scale and the Problem Areas in Diabetes scale to assess diabetes distress in 3338 adults with diabetes (1609 completed the Problem Areas in Diabetes scale (n = 675 type 1 diabetes; n = 934 type 2 diabetes) and 1705 completed the Diabetes Distress Scale (n = 693 type 1 diabetes; n = 1012 type 2 diabetes)). While criterion and convergent validity were good, Rasch analysis revealed suboptimal precision and targeting, and item misfit. Unresolvable multidimensionality within the Diabetes Distress Scale suggests a total score should be avoided, while suboptimal precision suggests that the Physician-related and Interpersonal distress subscales should be used cautiously.

Patients' causal beliefs about diabetic retinopathy.

Purpose This study explored patients’ understanding of the risk factors for diabetic retinopathy (DR) and their personal beliefs about the cause and controllability of their own DR, as well as health professionals’ perceptions of patients’ understanding of DR and its cause. Methods Eight focus groups and 18 semistructured interviews were conducted with 57 patients with DR, and seven semistructured interviews were conducted with diabetes and ophthalmic specialists. Sessions were transcribed verbatim and iteratively analyzed using the constant comparative method and NVIVO software. Results Nearly 50% of participants had proliferative DR, and most patients had undergone laser treatment. Patients had a reasonable understanding of the basic risk factors for DR such as diabetes control, although they were less clear about specific risk factors such as blood pressure and lipid control. Regarding their own disease, most patients attributed their DR either to poor diabetes control or to failings of the health care system. Some patients believed that their DR was a result of health aspects beyond their control or environmental factors, whereas others were unsure about the cause. Diabetes and ophthalmic specialists believed that many patients lacked understanding about the cause of their DR and the goal and outcome of laser treatment. Difficulty communicating the abstract concept of laser treatment outcomes in the face of concrete (yet erroneous) anecdotal evidence of the detrimental impact of laser on visual acuity was highlighted as a major barrier to mitigating patients’ harmful beliefs about treatment. Conclusions This study revealed some important gaps in patients’ knowledge and potentially damaging beliefs about the cause and treatment of DR despite most patients having considerable exposure to eye health professionals and DR treatment. Improving patients’ understanding of the major risk factors for DR and the realistic outcomes of laser treatment may improve patients’ coping mechanisms, adaption to disease, and ocular outcomes.

Combined poor diabetes control indicators are associated with higher risks of diabetic retinopathy and macular edema than poor glycemic control alone

Purpose To examine the association of individual and combined indicators of diabetes control with diabetic retinopathy and diabetic macular edema. Materials and methods In this clinical, cross-sectional study, 613 adults with type 2 diabetes (372 any diabetic retinopathy; 183 any diabetic macular edema) were examined. Diabetic retinopathy was assessed from fundus photographs; diabetic macular edema from Ocular Coherence Tomography scans; and HbA1c and serum lipid values from fasting blood samples. Poor glucose control was defined as HbA1c≥7%; poor blood pressure control as SBP≥130/DBP≥80; and poor lipid control as total cholesterol:HDL ratio≥4.0. The association of poor glucose control, poor blood pressure control and poor lipid control alone and in combination (poor glucose & blood pressure control; poor glucose & lipid control; poor blood pressure & lipid control; and poor glucose, blood pressure & lipid control) with diabetic retinopathy/diabetic macular edema was examined using multiple logistic regression models. Results Patients’ mean±standard deviation age was 64.9±11.6 years (57% male). In adjusted models, compared to those with good control of all indicators (n = 99, 18.3%), the odds ratio (95% Confidence Interval) of having any diabetic retinopathy was 2.44 (1.34–4.46), 3.75 (1.75–8.07), 4.64 (2.13–10.12) and 2.28 (1.01–5.16) for poor glucose control only; poor glucose & blood pressure control; poor glucose & lipid control; and poor glucose, blood pressure & lipid control, respectively. Correspondingly for diabetic macular edema, they were 3.19 (1.55–6.59); 3.60 (1.58–8.22); 2.76 (1.18–6.44); and 3.01 (1.18–7.67), respectively. Odds were not significantly increased for other indicators. Discussion Compared to individual indicators of poor diabetes control, risk of diabetic retinopathy and diabetic macular edema increased three to fourfold with a combination of these indicators. Targeting combined diabetes control indicators is important to reduce risk of diabetic retinopathy/diabetic macular edema.