Glaucoma is the second leading cause of blindness worldwide. It is estimated that 4.5 million people worldwide are blind due to glaucoma, with more than one third in China.1 Glaucoma impacts individuals at various levels, such as reduced ability to carry out self-care activities,2 dependence,3 depression,4 falls,5 traffic accidents,6,7 increased risk of hip fracture,8,9 and increased mortality.2 The decreased satisfaction of life caused by glaucoma is comparable with that induced by other chronic diseases such as diabetes, asthma, and coronary heart disease.6 Since the 1980s, the quality of life, reflecting a new concept of health and medical pattern change toward holistic care, was introduced to ophthalmology as an evaluating indicator. Compared with the general quality of life evaluation tools, vision-related quality of life measurements have been widely accepted as specifically reflecting the impact of visual function impairment on the individual.10 The systemic survey and investigation of vision-related life quality among patients with glaucoma has been performed in many countries, however, not in China. Previous investigation on the influential factors related to vision-related quality of life among glaucoma patients has mainly focused on clinical types, visual function, and treatment regimen. The conclusions, however, have varied. Some previous studies11,12 have indicated that conventional clinical measures such as visual acuity (VA) and visual field assessments failed to fully capture the picture of visual disability on daily visual functioning and on abilities to perform activities of daily living that are valued by patients. These results indicated that there were still many unknown factors to be explored.
Self-management, which has been widely accepted as a new preferred paradigm of chronic disease treatment and management in the world, reflects the revolutionary transformation from passive compliance to active participation in the management of chronic disease. Some pertinent studies that focused on chronic disease showed that self-management has become a guarantee of life quality.13,14 Herein, we investigated the influence of demographic variables, disease information and self-management behavior on the vision-related quality of life for patients with glaucoma. The results may provide some hints for the improvement and amendment of the current manner of care for patients with glaucoma.
This study received approval by the institutional review board at Shanghai Eye, Ear, Nose and Throat (EENT) hospital and written informed consent as given by all participants. We recruited the participants at the Eye clinic of Shanghai EENT hospital affiliated to Fudan University, in east China, which is the largest eye care hospital in China. The glaucoma outpatient service of this hospital is the referral center which accepts glaucoma patients all over China.
Consecutive eligible patients were selected over the period of June to September, 2009 in the Eye and ENT Hospital of Fudan University. The inclusion criteria were: diagnosis of primary glaucoma; received treatment for >1 week and needed long-term drug therapy; were 18 years of age or older; had no cognitive impairment and a certain reading ability; and volunteered to participate in this survey. Patients with suspected glaucoma or with any other history of optic neuropathy other than glaucoma were excluded. Questionnaires were administered to 171 patients, 4 cases of incomplete data were excluded and 167 cases of data were included in the final analysis.
Glaucoma Self-management Questionnaire
Self-management was measured by the Glaucoma Self-Management Questionnaire (GSMQ), which was developed by the first author based on clinical experience, literature review,10,14 consultation with experts in glaucoma (1 physician and 2 registered nurses), and interviews with 24 glaucoma patients.15 The 17-item scale was developed and a full evaluation of the psychometric properties was undertaken.
Firstly, 5 experts (2 ophthalmic nurses, 1 ophthalmic doctor, and 2 nursing educators) evaluated the content validity of the questionnaire, and the results showed that the content validity index was 0.98. To examine validity, we used exploratory factor analysis, principal component analysis followed by varimax rotation. The appropriate test of sampling showed that the Kaiser-Meyer-Olkin=0.860 and the Bartlett’s test of sphericity χ2 value was 2109.14 (df=136, P<0.001). To consider a factor as good and to be retained; the criterion of eigen values >1 was used. Items were included only if they loaded on a single factor and had a loading >0.4. During this procedure, no item was deleted. Factor analysis identified a 3-factor structure that explained 65.96% of the cumulative variation. The 3-factor construct was consistent with the authors’ theoretical hypotheses and was named as: life adjustment, body function promotion, and medical management of disease.
The life adjustment dimension has 3 items that measure patients’ lifestyle modifying action while facing glaucoma-related problems. Sample items are “I control the time for watching TV or using computer” and “I avoid wearing tight collared suit.” The body function promotion dimension has 6 items regarding how much the patient’s effort to make body to function effectively. Sample items are “I do excises on regularly base” and “I try to cope with daily circumstances and to deal with personal feelings in a positive and optimistic manner.” The dimension of medical management of disease has 8 items indicating patients involvement of medical control of glaucoma, for example, medication-taking and refill compliance, return for clinical follow-up, and recognizing the warning signs that should alert him/her to see the doctor. Responses to all subscales are rated on a 5-point Likert-type scale, ranging from 0 (never do it this way) to 4 (always do it this way), with a higher score indicating better self-management behavior. A pilot study showed that the Cronbach α of each dimension and total scale reached >0.7. The test-retest data were obtained from a random sample of 20 patients with surveys performed 2 weeks apart. The scores for test and retest in these 20 participants were significantly and highly correlated (correlation coefficients in range from 0.612 to 0.833, P<0.05).
National Eye Institute Visual Function Questionnaire-25 (NEI-VFQ-25)
The questionnaire NEI-VFQ-25, developed by Mangione et al,16 was widely used for evaluation of vision-related quality of life. The questionnaire contains 25 items that are grouped into 12 sub-scales including: general health (GH, 1 item); general vision (GV, 1 item); ocular pain (2 items); difficulty with near-vision activities (3 items); difficulty with distance-vision activities (3 items); limitation of social functioning because of vision (2 items); mental health problems because of vision (4 items); role limitations because of vision (2 items); dependency on others because of vision (3 items); driving difficulties (2 items); difficulty with color vision (CV, 1 item); and difficulty with peripheral vision (1 item). Each subscale score was converted to a score between 0 and 100, and higher scores indicated better vision-specific HRQOL. The composite VFQ 25 score is the mean score of all items except for the general health item.16 This questionnaire was translated into traditional Chinese by Hong Kong researchers in 2008,17 and has not been used in mainland China previously. In the pilot study, the Cronbach α coefficients for each dimension of VFQ were between 0.638 and 0.931, and the test-retest coefficients were between 0.660 and 0.934.
VA was assessed with a Snellen E chart at a distance of 5 m and recorded separately for each eye by their ophthalmologists. Snellen E is the current national standard of acuity measurement in China.18 The binocular visual acuity (BVA) was used for VA evaluation as the analysis of self-management behaviors and quality of life in patients should be based on the status of binocular vision. The BVA grading standard presented by He and Xu19 was used.
Intraocular pressure (IOP) was examined using Goldmann applanation tonometry (HAAG-STREIT 900, Haag-Streit, Swiss). Visual field analysis was performed with Automated perimetry (Humphrey 750, Carl Zeiss Meditec, Dublin, CA) using a 30-2 threshold program with SITA standard strategy. Mean deviation (MD) were recorded for bilateral eyes in all cases. All visual function data were collected within 3 months of enrolment in the study.
Demographic information regarding age, sex, marital status, educational background, occupation, and economic income was collected by face-to-face interviews conducted by the first author. Disease variables were recorded based on medical chart review, and the remaining questionnaire and scales were completed by the patients independently.
For the subjects with seriously impaired vision or writing difficulties, the researchers stated the question and possible answers in a neutral tone for their independent choice and the researchers accurately recorded their answers. IOP, VA, and visual fields were examined and recorded by professionals. All these examinations were within the routine items for glaucoma patient follow-up visits and no extra burden was imposed.
All statistical analyses were performed with the SPSS version 16.0 software platform (SPSS Inc., Chicago, IL). Descriptive statistics were obtained with application of frequency, percentage, mean, and SD. Multiple linear stepwise regression was used to identify predictive factors for vision-related quality of life. P values of ≤0.05 (2-sided) were considered statistically significant.
The characteristics of these 167 subjects are shown below: age (20 to 78 y; mean, 53.81±13.51 y); sex (male/female, 76/91); education (middle and secondary school 91, 54.5%); currently being married (133, 56.3%); middle economic burden (75, 44.9%); type of glaucoma (open angle/angle closure: 94/72, 56.3%/43.7%); with positive family history of glaucoma (55, 32.9%); with disease duration of 1 to 5 years (73, 43.7%); ever received surgery or laser treatment (83, 49.7%); using 2 or more antiglaucoma drugs (95, 56.9%); combined with one or more comorbidities (77, 47.1%). Nearly half of the participants (76, 45.5%) were employed (full time or part time). One hundred thirty-two (79.0%) patients declared living with family members. Regarding systemic diseases, 22 patients had hypertension, 18 had diabetes mellitus, 23 had cardiovascular diseases, 9 had chronic obstructive pulmonary disease, and 5 had asthma. The mean value of IOP in the better eye was 19.19±4.71 mm Hg and the worse eye 19.77±5.96 mm Hg; MD in the better eye (−8.23±7.33 dB) and the worse eye (−11.23±9.12 dB). More than half (123, 73.7%) of the participants’ BVA was grading as normal or near normal, and 11 were considered legally blind.
Results for Self-management Behavior
Regarding the scores for the 3 dimensions of GSMQ, the medical management of disease was the highest (3.39±0.60), followed by body function promotion (3.24±0.60) and life adjustment to the lowest (2.80±0.63). The relationship between self-management behavior and demographic (age, sex, education, marital status, employment, economic status) and disease variables (disease duration, morbidity, family history of glaucoma, number of medications, number of instillations, BVA, IOP, and MD value for both eyes) was assessed in a univariate manner using either an analysis of variance (for categorical predictors) or linear regression (for continuous predictors). Higher economic income patients demonstrated higher scores in life-adjustment subscale (F=4.526, P=0.032). Patients with higher levels of education (F=3.312, P=0.022), currently being married (F=4.489, P=0.012), living with family (F=5.363, P=0.002), less number of instillations (F=3.857, P=0.020) presented higher scores in body function promotion. Patients with primary open-angle glaucoma (F=5.952, P=0.017), ever received laser or surgery (F=8.837, P=0.002), and less number of medicine (F=3.145, P=0.044) got higher scores in medical management of disease. No differences were detected between any GSMQ subscale scores and neither the rest of the indices (age, sex, working status, family history of glaucoma, BVA, IOP, and MD value), nor the comorbidities (chronic obstructive pulmonary disease, arterial hypertension, cardiovascular disease, asthma, and diabetes mellitus)—detailed data are not shown.
Results of the NEI-VFQ-25
Among all dimensions of NEI-VFQ-25, the lowest score was for GH, followed by GV, and the highest score was for the dimension of CV. The composite score was 69.21±16.21 points. The detailed results are presented in Table 1.
Regression Analysis of Factors Influencing the Vision-related Quality of Life
The NEI-VFQ-25 composite score was set as the dependent variable, and sex, age, education level, marital status, working status, economic burden, disease duration, morbidity, family history of glaucoma, grade of BVA, IOP (both eyes), MD (both eyes), and the 3 subscales of GSMQ (life adjustment, body function promotion, and medical management of disease), were considered as independent variables in a multiple linear regression model.
The results in Table 2 show the predictor variables of the NEI-VFQ-25 overall composite score including life adjustment, body function promotion, positive family history, and BVA. These could explain 29.2% of the variation of the NEI-VFQ-25 composite score. Demographic variables failed to enter in the regression model.
There are several limitations to our study. This study was set in an academic teaching center which specializes exclusively in eye disease and all of the participants belonged to the dominant Han ethnicity. This factor, combined with the relatively small sample, may limit the transferability of the findings. Secondly, the self-management behaviors was subjectively assessed and no objective measures were obtained. In addition, although this study examined several factors that may affect self-management and QoL, by no means were all potential variables included. To address these limitations, we exercised rigorous quality control procedures to ensure high participant response rates and quality data.
To our knowledge, this is the first study using the NEI-VFQ-25 questionnaire in mainland China. In our data, the score of GH (32.78±23.59 points) was the lowest, followed by the scores for GV (46.35±19.52 points) and vision-specific role difficulties (55.54±22.70 points). The highest score was the dimension of CV (89.02±20.76). These results are consistent with previous studies.20–23 When the survey was performed in different countries and regions, similar results showed that the 2 dimensions receiving the lowest scores were always GH and GV. These results indicate that the 2 dimensions are significantly related to vision-related quality of life for patients with glaucoma in various regions and ethnicities. In this study, the NEI-VFQ-25 composite score was 69.21±16.21, which was similar to that in Japan, reported by Suzukamo and colleagues (n=69, 69.8±1.9)21 and slightly lower than that in the United States, reported by Jampel et al4 (n=191, 77.3±15.5). The scores of the remaining dimensions were distributed between 55 points and 80 points, and showed a similar trend to those previously mentioned studies. This result indicates that, in China, the vision-related quality of life among patients with glaucoma is at a moderate level. Participants with the following characteristics had low QOL scores: worse scores on the subscales of GSMQ, a positive family history of glaucoma, and worse BVA.
Assessment of self-management behavior by means of questionnaires has received a great deal of attention but had not been explored previously in glaucoma patients. Our results suggest that glaucoma patients had good overall self-management, as indicated by mean scores over 70% of the possible score in all 3 dimensions. Medical management of disease and body function promotion, which are essential aspects of self-management, were carried out well. A possible explanation may lie in the fact that the illness situation for glaucoma tends to be fairly stable over a certain period, and patients are more likely to learn how to carry out the relevant self-management skills during such a time frame. However, regarding the glaucoma patients’ self-management, this study are not conclusive and need more investigation, particularly because there is a lack of research by which to compare the findings of the present study.
Regression analysis indicated that the 2 dimensions, life adjustment and functional health, in self-management behavior showed a prediction effect on the dependent variable. This result suggests that self-management behavior has a positive impact on the vision-related quality of life in glaucoma patients. In other words, better self-management behavior means higher vision-related quality of life. It has been reported that self-management plays a positive role in quality of life in many chronic diseases.24–26 In the field of ophthalmology, randomized controlled trials performed by Brody et al26 on age-related macular degeneration patient self-management indicated that the patient group (n=87) trained with self-management skills showed fewer symptoms of emotional distress and higher life quality (measured with NEI-VFQ-25), especially showing a significantly higher score for functional dimension. They concluded that self-management is a very effective intervention strategy, especially for older patients with both impaired vision and symptoms of depression. The results of 6 months follow-up study27 showed that patients with good self-management behavior had significantly reduced emotional distress and improved physical function. This means that self-management has a long-term positive impact on improving the quality of life. The results of the latest randomized controlled trial28 supported short-term effects of self-management behavioral intervention in older patients with impaired vision (12 wk follow-up). Compared with the control group, patients in the experimental group had improved (effect size ranged from 0.1 to 0.3) quality of life (measured with SF-36) and adapting ability to impaired vision (measured with AVLS). In this study, self-management behavior was the only factor that could predict the vision-related quality of life in glaucoma patients in addition to those with a family history of glaucoma and the binocular integrated visual classification. This result highlights the necessity of the implementation of self-management education and training for the glaucoma patients. The results also give a strong reference for the carrying out of community care model for glaucoma patients, as these patients need to return to their family and society and be independent of the medical care eventually. It is very necessary to carry out self-management education for these patients, and help them to cope with the impact of glaucoma and enhance their quality of life.
It should be noted that, currently in China, the strategies for using self-management to assist with symptoms, life stress, and emotional management among patients with glaucoma has not yet begun. The nursing educators and managers should become aware that nurses urgently need to be trained to develop the ability to help patients perform self-management behaviors.
Previous studies have described the relationship between glaucoma and genetics, and a recent population-based survey research concluded that 60% of primary open-angle glaucoma is familial.29 The fraction of patients with a positive family history was up to 1/3 of the total population, and this result was similar to that found in Taiwan19 and Beijing (by Sun).30 In this study, the positive family history of glaucoma was found as a negative predictor of vision-related quality of life. In our previous studies,15,31 glaucoma patients with a positive family history reported more fear of going blind and had psychological shadows than the control group. These patients worried that the other family members would become affected, or had an increased negative experience after seeing the other family members becoming patients. Therefore, these factors affected their subjective evaluation of the global quality of life. These results suggest that, in clinical practice, more attention and support should be given to patients with familial glaucoma, and understanding the patient’s situation and providing effective nursing intervention may be helpful to them while adapting to the adverse impact of the disease. As strong evidence showed that glaucoma has a tight relationship with heredity,29,32 carrying out genetic counseling and prenatal care for women in the glaucoma population should be started as soon as possible.
The visually impaired are undoubtedly among the most vulnerable and neglected groups of society. In this study, BVA was a predictive factor of vision-related quality of life in patients with glaucoma, and this result was consistent with previous studies.6,33,34 The conclusion of these studies agreed that the quality of life of patients with severe visual impairment was impacted more apparently than others. In the study conducted by Swamy et al,34 BVA could explain 29.5% of the total scores of NEI-VFQ-25, and in the study of Van Gestel et al,35 the VA of the better eye and of the worse eye could explain 25.6% and 22.2% of the total scores of NEI-VFQ-25, respectively. The research performed by Varma et al,36 of the Los Angeles Eye Research Organization, revealed that the NEI-VFQ-25 composite score among glaucoma patients with medium and severely impaired vision were significantly lower than those without significant visual impairment. However, a study conducted by Yi et al37 in Changsha (located in south central China), showed no significant correlation between the quality of life and vision in older patients with glaucoma (r=0.374, P>0.05). A possible reason is that the age distribution of subjects in that survey ranged from 60 to 92 years, which is quite different from our survey. In our study, there was a negative correlation between BVA and vision-related quality of life. In other words, severe visual impairment meant poor vision-related quality of life. This result indicates that appropriate treatment for glaucoma to prevent vision loss is pivotal for patients to maintain their quality of life, and patients with a severe degree of impaired vision need more support. The government and public service departments should provide more substantial assistance, such as providing aids and opportunities for employment and education for the visually impaired, to improve their quality of life. In addition, popularizing comprehensive ophthalmology examinations to diagnose and treat glaucoma early benefits in visually impaired people as the visual impairment caused by glaucoma is irreversible.
In summary, the predictive factors for vision-related quality of life in patients with glaucoma include self-management behavior, positive family history, and BVA, but not demographic variables. It must be noted that independent variables have limited explanatory power on vision-related quality of life in this study. This result indicates that there must be many potential variables, for example, difficulty with hearing, motor control, strength, and posture/mobility factors, were not included in this survey, and more studies and more precise statistical methods need to be performed for more conclusive evidence.
Our results indicate that the vision-related quality of life in glaucoma patients is at a moderate level in China. Self-management behavior is an important predictor. Demographic data may not increase the explanatory effect. Our findings may help health care professionals have a deeper understanding of self-management affecting quality of life in glaucoma patients, and thereby aid in the design of strategies to maintain or improve quality of life and self-management. Future research should focus on how to integrate self-management skills into routine nursing practice for patients with glaucoma.
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