 |
|
The Impact of Diabetic Retinopathy on Participation in Daily Living
Ecosse L. Lamoureux, PhD;
Jennifer B. Hassell, BA;
Jill E. Keeffe, PhD
Arch Ophthalmol. 2004;122:84-88.
ABSTRACT
| |
Objective To determine the restriction of participation in daily activities of people with diabetic retinopathy using the Impact of Vision Impairment questionnaire.
Methods Individuals with diabetic retinopathy and a visual acuity (VA) worse than 20/40 or 6/12 in the better eye were eligible. Participants answered demographic questions and had VA information abstracted from medical records. If VA information was unavailable, it was assessed by an orthoptist.
Main Outcome Measures All participants completed the Impact of Vision Impairment questionnaire, which was either self-administered or interviewer administered. The physical and mental health components were assessed using the Medical Outcomes Study 12-Item Short Form (SF-12) questionnaire.
Results Forty-five participants (mean age, 67.5 years) were recruited, with almost 70% (30/45) recording a VA worse than 20/60 or 6/18 in the better eye. The median duration of vision loss was 2.0 years. The highest restriction was reported for the Leisure and Work, Mobility, and Consumer and Social Interaction domains (mean, 3.0, 2.8, and 2.8, respectively), compared with the Emotional Reaction to Visual Loss and Household and Personal Care domains (mean, 2.3 and 2.1, respectively) (P<.005). The activities with the greatest restriction of participation were reading print, mobility, work, and leisure. A poorer VA in the better eye correlated independently with increased restriction of participation, as measured by the Impact of Vision Impairment questionnaire scores (partial correlations, 0.29-0.41; P .03).
Conclusion Low-vision rehabilitation services aiming to improve outdoor mobility, print reading, participation in leisure activities, and psychological health may be an effective strategy to help people with diabetic retinopathy increase their participation in daily activities.
INTRODUCTION
Diabetic retinopathy (DR) is an important cause of visual loss in adults, with significant medical, social, and financial consequences.1 The prevalence of DR among people with diabetes mellitus in Australia and the United States is between 22% and 36%.2-6 A best-corrected visual acuity (VA) of 20/200 or worse has been estimated to be 25 times more prevalent in the diabetic population than in those without the disease.7-9 Vision impairment resulting from DR can, however, be prevented with regular screening and timely treatment.10
Vision impairment has been linked with dependency in activities of daily living,11-13 social isolation,14 and reduced physical activity.15 Several studies16-19 have also examined the relationship between different measures of vision and disability. However, the magnitude of restriction of participation in daily activities as a consequence of vision impairment has not been extensively investigated. Restriction of participation, previously known as handicap, is the limitation due to an impairment or disability on activities that an individual needs or wants to perform.20 By assessing restriction of participation, it is possible to design and implement strategies to effectively increase participation and consequently improve the quality of life of visually impaired people. Recently, the Centre for Eye Research Australia developed and validated a questionnaire that can measure a person's restriction of participation in 32 items. The Impact of Vision Impairment (IVI) questionnaire has been shown to be valid and reliable,21 but has not yet been used to measure the impact of the restriction of participation of a specific eye disease in the general population.
This investigation, therefore, quantifies and describes the restriction of participation in daily activities subsequent to vision impairment in people with DR using the IVI questionnaire.
METHODS
Participants were recruited from the Vision Australia Foundation (VAF; Victoria, Australia), a low-vision service provider, and The Royal Victorian Eye and Ear Hospital (RVEEH), East Melbourne. Only participants with no history of vision rehabilitation were included. Other criteria for inclusion were a VA worse than 20/40 or 6/12 in the better eye, a diagnosis of DR as the main condition causing vision loss, the ability to converse in English, and being 18 years or older. All participants were informed of the nature and purpose of the study, and gave witnessed consent. All participants answered demographic questions regarding age, duration of vision impairment, hearing loss, other health conditions, and limitations on performing daily activities attributed to other health conditions. Participants completed the IVI questionnaire. The study received ethics approval from the RVEEH and VAF in accordance with the Declaration of Helsinki for research involving human subjects.
Participants underwent eye examinations that included measurement of VA, and underwent refraction as a routine part of their appointments at the RVEEH and the VAF. If VA information was unavailable, qualified personnel assessed it. The best-corrected distance VA and near VA in the better eye were abstracted from the files for the participants. The distance VA was categorized as mild (<20/40 to 20/60 [<6/12 to 6/18]), moderate (<20/60 to 20/200 [<6/18 to 6/60]), and severe (<20/200 [<6/60]). The near VA was categorized as N8 or better, less than N8 to N20, less than N20 to N48, and less than N48.
A detailed description of the IVI questionnaire has been fully published elsewhere.21 Briefly, the IVI questionnaire comprised 32 items grouped under 5 domains (Leisure and Work, Consumer and Social Interaction, Household and Personal Care, Mobility, and Emotional Reaction to Vision Loss). Participants with a VA sufficient to read large print (18-point font) self-administered the questionnaire before their first visit at the low-vision clinics. Otherwise, the 32-item IVI questionnaire was interviewer administered at the participant's first visit at the RVEEH and the VAF. The interviewer (J.B.H.) was trained to administer the IVI questionnaire. Proxy answers were not solicited from caregivers or relatives to avoid biasing the IVI questionnaire responses to the perception of another person's opinion of the participant's ability. High levels of consistency have been shown between self- and interview-administered methods for the IVI questionnaires.21
Responses to the IVI questionnaire items under the domains were rated as follows: "not at all" (0), "rarely" (1), "a little" (2), "a fair amount" (3), "a lot" (4), "can't do because of eyesight" (5), or "don't do because of other reasons" (8). Responses to the items under the Emotional Reaction to Vision Loss domain were rated as follows: "not at all" (0), "very rarely" (1), "a little of the time" (2), "a fair amount of the time" (3), "a lot of the time" (4), "all of the time" (5), or "don't do because of other reasons" (8). Data in parentheses are scores. Total and domain scores of the IVI questionnaire are an arithmetic average of items rated between 0 (the best score) and 5 (the worst score). An item rated with a score of 8 was not included in the final average score, and was analyzed separately.
Participants also completed the Medical Outcomes Study 12-Item Short Form (SF-12; version 1: Physical and Mental Health Summary Scales). The SF-12 (a short validated version of the Medical Outcomes Study 36-Item Short-Form Health Survey) was included to evaluate the physical and mental health components of the participants. It was also used to determine if the overall health of the participants was a potential confounder when assessing the relationship between IVI questionnaire score and other variables of interest. By using the algorithm developed by Ware and associates,22 2 summary components related to the physical (Physical Summary Scale) and mental (Mental Summary Scale) domains of life were computed from the questions in the SF-12. Each summary scale is scored from 0 to 100, where 100 indicates the best possible score and 0 represents the worst possible score.
Descriptive analyses were performed to characterize the sociodemographic, health, and clinical characteristics of the study participants. Spearman rank correlation tests were performed to determine the association between the IVI questionnaire scores and the participants' demographic and clinical characteristics. The Mantel-Haenszel test was used to determine the association between VA and the IVI questionnaire domain and overall scores. The partial correlations procedure was used to compute partial correlation coefficients between VA and the IVI questionnaire scores while controlling for age, sex, the duration of eye impairment, comorbidity, Physical Summary Scale score, and Mental Summary Scale score. The Wilcoxon rank sum tests were selected to compare differences in the distributions of IVI questionnaire domains, and the  2 tests were used to compare proportions. An  level of P<.05 was chosen as the criterion for significance for all the statistical tests, except for the Wilcoxon rank sum test, which was set at P<.005 because of the many paired comparisons undertaken.
RESULTS
Forty-five subjects (20 men) with DR as their main cause of vision loss participated in the study (Table 1). Twenty-seven subjects were clients of the VAF, and the remaining 18 were patients of the RVEEH. More than 53% (24/45) of the participants were born in Australia, and nearly 80% (35/45) used English as the main spoken language at home. All participants had diabetes mellitus and other diabetic-related health complications, such as hypertension, a heart condition, gout, and asthma. Of the participants, 42% (19/45) reported that other health conditions interfered "a great deal" with their activities. Only 6 subjects were employed either part time or full time, and they were aged between 47 and 59 years.
|
|
|
|
Table 1. Demographic and Clinical Characteristics of the 45 Study Participants
|
|
|
Almost 70% of the participants had a distance VA worse than 20/60 in the better eye when they were first seen (Table 1). Following refraction, 56% had a distance VA worse than 20/60. Only 40% of the participants recorded a score of N8 or better. The median duration of vision impairment was 2.0 years (range, 0-33 years). Almost 18% (8/45) of the participants reported having their vision affected for 10 years or longer.
The mean domain and overall scores were greater than 2, indicating that on average the participants ranked the items in the domains between a little and a fair amount of restriction. The highest scores were recorded for the Leisure and Work, Mobility, and Consumer and Social Interaction domains (mean scores, 3.0, 2.8, and 2.8, respectively), compared with the Emotional Reaction to Vision Loss and Household and Personal Care domains (mean scores, 2.3 and 2.1, respectively) (Figure 1) (Wilcoxon rank sum test, P<.005).
|
|
|
|
Figure 1. The box-and-whisker plot summaries of the 5 Impact of Vision Impairment (IVI) questionnaire domains for the 45 participants. Leisure indicates Leisure and Work; Consumer, Consumer and Social Interaction; Emotional, Emotional Reaction to Vision Loss; and Household, Household and Personal Care.
|
|
|
The mean ± SD score of the individual IVI questionnaire items was 2.6 ± 1.1 (range, 1.4-4.0) (Table 2). When ranked from the most restrictive items, 11 items showed that the participants experienced between a fair amount and a lot of restriction in these activities (mean scores, 3-4) (Table 2). Of the items with the greatest magnitude of restriction, 3 were from the Mobility and Emotional Reaction to Vision Loss domains each and 2 were from the Leisure and Work and Consumer and Social Interaction domains each. Most of the items of the Household and Personal Care domain caused little restriction for the study participants (Table 2).
|
|
|
|
Table 2. Score for the IVI Questionnaire Individual Items, Ranked in Order of Difficulty, and for Each Category Response of the 45 Participants
|
|
|
The reading of small print, labels, and street signs caused the greatest restriction because these activities were among the items with the highest mean scores (Table 2). Participation in paid work or leisure activities was also rated as fairly restrictive, with mean scores ranging between 2.8 and 3.4. Three items with a high degree of restriction were associated with mobility (public transport use, obstructed locomotion [eg, stairs and curbs], and fear of falling) (mean score, 3.0). The participants also highly rated 3 emotional health–related items and stated that for a fair amount to a lot of the time they were concerned because their eyesight was getting worse and they felt frustrated and like a nuisance because of their DR. On the other hand, the participants did not feel overly sad, depressed, or lonely because of their eyesight, because these 3 items from the Emotional Reaction to Vision Loss domain scored between 1.4 and 1.8.
There was at least one category response of cannot do because of eyesight for each item of the IVI questionnaire (Table 2). Eight items recorded at least 20% of the total responses as cannot do because of eyesight. These items were "Reading ordinary size print," "Reading a sign across the street," "Reading labels or instructions on medicines," "Favorite pastimes or hobbies," "Worried because eyesight getting worse," "Paid or voluntary work," "Eyesight interfered with using transport," and "Frustrated or annoyed because of your eyesight." No significant differences were found in the proportions of those who reported cannot do because of eyesight and the other responses for age, sex, near and distance VA, and duration of vision loss (2 test, P>.05 for all).
No significant statistical correlations (Spearman rank correlation, P>.05) were found between VA and age, sex, level of education, and duration of visual impairment. On the other hand, a poorer distance VA in the better eye significantly correlated with the increased restriction in the IVI questionnaire domain scores (Mantel-Haenszel test, 5.9-7.9; P.02) (Figure 2). The association was still evident after controlling for age, sex, duration of vision loss, comorbidity, Physical Summary Scale score, and Mental Summary Scale score (partial correlations, 0.29-0.41; P range, .01-.03).
|
|
|
|
Figure 2. Stratified visual acuity (VA) box-and-whisker plots of the 5 Impact of Vision Impairment (IVI) questionnaire domains. There was a significant association between VA and the Leisure (Mantel-Haenszel 2 [MH], 6.5; P = .01), Household (MH, 6.0; P = .01), Consumer (MH, 7.9; P<.001), Emotional (MH, 6.8; P<.001), and Mobility (MH, 5.9; P = .02) domains. The domains are explained in the legend to Figure 1.
|
|
|
COMMENT
Our participants reported that the functional life domains causing the greatest restriction of participation because of their DR were Leisure and Work, Mobility, Consumer and Social Interaction, and the Emotional Reaction to Vision Loss, with 19 of the 20 most restrictive items originating from these 4 domains. The Household and Personal Care domain, on the other hand, was the least restrictive. Between a moderate and a lot of restriction of participation was reported for activities associated with print reading, work, leisure, the use of public transport, and outdoor mobility. Our results show that people with DR experience at least a moderate amount of restriction of participation in a range of daily activities and life domains fundamental to a good quality of life.
Our domain and individual rankings were similar to those of 2 studies that also used the IVI questionnaire, namely, those of Hassell et al,23 using patients with glaucoma, and Weih et al,21 who recruited participants with age-related maculopathy, glaucoma, DR, cataract, and other retinopathies. Collectively, these findings demonstrate the relevance of the IVI questionnaire as a meaningful questionnaire to identify the nature and magnitude of restriction of participation in daily activities for visually impaired individuals.
The Household and Personal Care domain low ranking is not surprising considering that familiarity with the household environment can make items like operating household appliances and not spilling and breaking things easier to undertake compared with items under the other domains. The distribution of the items under the Emotional Reaction to Vision Loss domain was also interesting. Our participants did not feel depressed or isolated, because items such as "Felt sad or low because of eyesight," "Embarrassed because of eyesight," and "Felt lonely or isolated because of eyesight" were lowly ranked. However, items such as "Worried because eyesight getting worse" and "Felt like a nuisance or burden because of eyesight" were ranked highly, with a mean score of 3.1. The high ranking of these items suggests that while the emotional domain recorded an overall mean score of 2.3, some items of this domain have a substantial amount of restriction of participation but may be masked by some relatively low scores of other items of the same domain. This finding suggests that despite our small sample size and the modest overall score of the emotional domain recorded in this study, a psychological component seems to be an essential aspect of vision rehabilitation strategies for individuals with DR.
Significant modest correlations were found between the IVI questionnaire score and VA in the better eye. In addition, a closer scrutiny of Figure 2 seems to show that participants with severe vision impairment (VA, <20/200) experience greater restriction of participation on the IVI questionnaire items than those with mild and moderate vision impairments (VA, <20/40 to 20/60 and 20/60 to 20/200, respectively). This observation suggests that eye care providers, when treating a severely vision-impaired individual, should inquire about participation in the essential domains of life. This finding also confirms that despite the relatively small sample size of the present study, the IVI questionnaire is a relevant and responsive instrument for assessing participation in vision-impaired individuals with different levels of VA.
The mean age of our participants was 68 years, and a third were younger than 60 years. While most eye conditions are age related, our sample with DR contained several relatively younger participants, probably because of the young age of onset of diabetes mellitus. Young persons whose condition is due to DR have also been observed among participants aged 50 to 59 years in the Baltimore Eye Study24 and the Melbourne Visual Impairment Project.25 More important, the mean overall IVI questionnaire score of our younger subjects was 3.1 (vs 2.3 for participants older than 60 years; P = .07), suggesting that the younger participants are experiencing similar restriction of participation. These data suggest that age should not be used as a guide to provide vision rehabilitation services to individuals with DR. Support for this suggestion is further provided because no significant correlation was found between age and the IVI questionnaire scores.
Finally, the findings of the present investigation should be viewed within 2 limitations. First, our sample size was relatively small because of the specific criteria restricting our participants' selection. Based on our study sample of 45 participants, the average level of participation score of 2.6 was estimated (95% confidence interval, 2.2-2.9). Second, we did not include a comparison group. Consequently, future investigations with larger sample sizes and comparison groups are required to confirm our findings. In addition, our sample was limited to participants who could converse in English, and the findings of this study should not be extended to the sections of the Australian non–English-speaking population.
In conclusion, the IVI questionnaire was designed to determine the degree of restriction of participation for people with impaired vision to provide effective rehabilitation strategies to increase participation. Based on our findings, low-vision rehabilitation services with programs aiming to improve outdoor mobility, print reading, participation in leisure activities, and psychological health could be an effective strategy to help individuals with DR increase their participation in activities of daily living.
AUTHOR INFORMATION
Corresponding author: Ecosse L. Lamoureux, PhD, Centre for Eye Research Australia, Department of Ophthalmology, University of Melbourne, Locked Bag 8, East Melbourne, Victoria 8002, Australia (e-mail: ecosse{at}unimelb.edu.au).
Submitted for publication December 4, 2002; final revision received August 24, 2003; accepted September 10, 2003.
From the Centre for Eye Research Australia, Department of Ophthalmology, University of Melbourne, East Melbourne. The authors have no relevant financial interest in this article.
REFERENCES
1. Klein R, Klein BE, Moss SE. The Wisconsin Epidemiologic Study of Diabetic Retinopathy: a review. Diabetes Metab Rev. 1989;5:559-570.
ISI
| PUBMED
2. Mitchell P, Smith W, Wang J, Attebo K. Prevalence of diabetic retinopathy in an older community: the Blue Mountains Eye Study. Ophthalmology. 1998;105:406-411.
FULL TEXT
|
ISI
| PUBMED
3. McKay R, McCarty C, Taylor H. Diabetic retinopathy in Victoria, Australia: the Visual Impairment Project. Br J Ophthalmol. 2000;84:865-870.
FREE FULL TEXT
4. Klein R, Klein BE, Moss SE, Davis MD, DeMets DL. The Wisconsin Epidemiologic Study of Diabetic Retinopathy, II. Arch Ophthalmol. 1984;102:520-526.
ABSTRACT
5. Klein R, Klein BE, Moss SE, Davis MD, DeMets DL. The Wisconsin Epidemiologic Study of Diabetic Retinopathy, Ill. Arch Ophthalmol. 1984;102:527-532.
ABSTRACT
6. Klein R, Klein BE, Moss SE. The Wisconsin Epidemiologic Study of Diabetic Retinopathy: an update. Aust N Z J Ophthalmol. 1990;18:19-22.
ISI
| PUBMED
7. Kahn H, Hiller R. Blindness caused by diabetic retinopathy. Am J Ophthalmol. 1974;78:58-67.
ISI
| PUBMED
8. Palmberg P. Diabetic retinopathy. Diabetes. 1977;26:703-709.
ISI
| PUBMED
9. Aiello L, Cahill M, Wong J. Systemic considerations in the management of diabetic retinopathy. Am J Ophthalmol. 2001;132:760-776.
FULL TEXT
|
ISI
| PUBMED
10. Ferris F 3rd. How effective are treatments for diabetic retinopathy? JAMA. 1993;269:1290-1291.
FULL TEXT
|
ISI
| PUBMED
11. Jette AM, Branch LG. Impairment and disability in the aged. J Chronic Dis. 1985;38:59-65.
FULL TEXT
|
ISI
| PUBMED
12. West SK, Munoz B, Rubin GS, et al, and the SEE project team. Function and visual impairment in a population-based study of older adults: the Salisbury Eye Evaluation project. Invest Ophthalmol Vis Sci. 1997;38:72-82.
FREE FULL TEXT
13. Carabellese C, Appollonio I, Rozzini R. Sensory impairment and quality of life in a community elderly population. J Am Geriatr Soc. 1993;41:401-407.
ISI
| PUBMED
14. Thompson J, Gibson J, Jagger C. The association between visual impairment and mortality in elderly people. Age Ageing. 1989;18:83-88.
FREE FULL TEXT
15. Hakkinen L. Vision in the elderly and its use in the social environment. Scand J Soc Med Suppl. 1984;35:5-60.
PUBMED
16. Ross J, Bron A, Clarke D. Contrast sensitivity and visual disability in chronic simple glaucoma. Br J Ophthalmol. 1984;68:821-827.
FREE FULL TEXT
17. Lennerstrand G, Ahlström CO. Contrast sensitivity in macular degeneration and the relation to subjective visual impairment. Acta Ophthalmol (Copenh). 1989;67:225-233.
PUBMED
18. Elliot D, Hurst M, Weatherill M. Comparing clinical tests of visual function in cataract with the patient's perceived visual disability. Eye. 1990;4:712-717.
19. Rubin G, Bandeen-Roche K, Huang G-H, et al. The association of multiple visual impairments with self-reported visual disability: SEE project. Invest Ophthalmol Vis Sci. 2001;42:64-72.
FREE FULL TEXT
20. ICF. International Classification of Functioning, Disability and Health. Geneva, Switzerland: World Health Organization; 2001.
21. Weih LM, Hassell JB, Keeffe J. Assessment of the Impact of Vision Impairment. Invest Ophthalmol Vis Sci. 2002;43:927-935.
FREE FULL TEXT
22. Ware J, Kosinski M, Keller S. SF-12: How to Score the SF-12 Physical and Mental Health Summary Scales. Lincoln, RI: QualityMetric Inc; 1998.
23. Hassell JB, Weih LM, Keeffe JE. Impact of age-related macular degeneration on participation in desired activities. Paper presented at: The 7th International Conference on Low Vision; July 24, 2002; Goteborg, Sweden.
24. Rahmani R, Tielsch J, Katz J, et al. The age-specific prevalence of visual impairment in an American urban population. Arch Ophthalmol. 1996;103:1721-1726.
25. Weih L, VanNewkirk M, McCarty C, Taylor H. Age-specific causes of bilateral visual impairment. Arch Ophthalmol. 2000;118:264-269.
FREE FULL TEXT
THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES
The Effectiveness of Low-Vision Rehabilitation on Participation in Daily Living and Quality of Life
Lamoureux et al.
IOVS 2007;48:1476-1482.
ABSTRACT
| FULL TEXT
The Impact of Vision Impairment Questionnaire: An Assessment of Its Domain Structure Using Confirmatory Factor Analysis and Rasch Analysis
Lamoureux et al.
IOVS 2007;48:1001-1006.
ABSTRACT
| FULL TEXT
The Impact of Vision Impairment Questionnaire: An Evaluation of Its Measurement Properties using Rasch Analysis
Lamoureux et al.
IOVS 2006;47:4732-4741.
ABSTRACT
| FULL TEXT
|
