Abstract
purpose. To investigate the prevalence and risk factors of correctable visual impairment and the quality of life of persons with correctable visual impairment in a metropolitan senior population.
methods. The study was a community-based, cross-sectional survey of vision and eye diseases among noninstitutionalized subjects aged 65 years and older in the Shihpai community of Taipei, Taiwan. The study consisted of a structured questionnaire followed by a comprehensive standardized ophthalmic examination included presenting and best corrected visual acuity, tonometry, slit lamp biomicroscopy, and direct and indirect ophthalmoscopy.
results. A total of 1361 subjects (response rate, 66.6%) participated in both completion of the questionnaire and ophthalmic examination. The prevalence of correctable visual impairment (presenting visual acuity in the better eye <6/12 that improved to no impairment [≥6/12] after refractive correction) was 9.55% (95% confidence interval [CI], 7.97%–11.13%). Under multiple logistic regression analysis, older age (≥75 years; odds ratio [OR], 2.41; 95% CI, 1.56–3.70) and nonemmetropic eyes (myopia; OR, 6.80; 95% CI, 3.77–12.77 vs. hyperopia; OR, 2.13; 95% CI, 1.29–3.51) were significantly related to correctable visual impairment. A higher level of education (OR, 0.52; 95% CI, 0.32–0.83) and wearing distance eyeglasses during the eye examination (OR, 0.23; 95% CI, 0.12–0.43) were protective factors for correctable visual impairment. Subjects with correctable visual impairment scored significantly lower in the physical functioning dimension of the SF-36 questionnaire (P < 0.001).
conclusions. The results demonstrate that approximately 10% of the senior population in the Shihpai district has a correctable visual impairment. Thus, it is important to educate the public about the importance of regular examination and the possibility of improving visual acuity by wearing glasses.
Visual impairment in older persons is of increasing importance because of the changes in life expectancy and the resultant growing senior population.
1 As people age, refractive error is one of the most frequent reasons for consultation with an eye care practitioner, and refractive error is the most common cause of impaired vision.
2 The earlier onset of refractive error compared with cataract accounts for twice as many blind-person years.
3 Although most population studies have assessed the impact of noncorrectable visual impairment, several
2 4 5 6 7 have documented a high frequency of older persons with correctable visual impairment. More important than a person’s best corrected visual acuity is the person’s day-to-day functional vision,
4 because it reflects the visual acuity a person experiences when performing daily activities. Therefore, correction of refractive error is one of the five priorities of Vision 2020: The Right to Sight, the World Health Organization’s Global Initiative for the Elimination of Avoidable Blindness.
8
There are few population-based studies on correctable visual impairment in older persons, especially in Asia. The purpose of this study was to investigate the prevalence of correctable visual impairment in older persons in Taipei, to assess the risk factors, and to determine the spectacle coverage rate in the senior population. Moreover, the difference in quality of life between subjects with correctable visual impairment and those without visual impairment was evaluated.
The Shihpai Eye Study was a community-based, cross-sectional survey of vision and eye diseases among noninstitutionalized subjects 65 years of age and older in Shihpai, Taipei, Taiwan. The Shihpai community is located in the Peitou district of Taipei. The population in the Peitou district at the end of 1999 was approximately 247,100, making it the second largest district in Taipei. This area was chosen because the population is relatively stable—that is, there was a 0.3% annual population increase between 1994 and 1999. The baseline examination was conducted between July 1, 1999, and December 31, 2000.
Details of sample selection and methods for the Shihpai Eye Study have been published.
9 In summary, residents 65 years of age and older were identified by using the household registration system. This system officially registers personal information such as date of birth, sex, and home address, as well as family members and relations. The system is designed to collate and supply demographic information for efficient city planning and competent socioeconomic developmental programs. It also provides highly accurate and complete population statistics and allows for the availability of reliable demographic data to assist scholars in academic research.
According to the official household registration in 1999, the total number of residents 65 years and older in Shihpai was 4750. Excluding vacant households (658 subjects); residents who died before contact (48 subjects); and inpatient, paralyzed, and disabled residents (298 subjects), 3746 persons were eligible, and 2045 of them were randomly selected to be invited to participate in the study.
The study consisted of a structured questionnaire used to obtain baseline information on demographic data (age, gender, locality, marital status, and education), personal medical history (diabetes mellitus, hypertension, and cardiovascular disease previously diagnosed by a physician), family history, and lifestyle (smoking and alcohol intake). The 36-item short-form survey of the Medical Outcomes Study (SF-36) was also administered by the same interviewer.
Subjects that were interviewed were invited to participate in a comprehensive ophthalmic examination conducted in Taipei Veterans General Hospital, which included presenting and best corrected visual acuity, tonometry, slit lamp biomicroscopy, and direct and indirect ophthalmoscopy. Ophthalmologists conducted the eye examination according to a standardized protocol. Informed consent was obtained from each subject before enrollment in the study.
This study was approved by the Institutional Review Board of the Taipei Veterans General Hospital and conducted according to the tenets of the Declaration of Helsinki of the World Medical Association regarding scientific research involving human subjects.
Visual acuity was assessed with a Snellen chart at a distance of 6 m and recorded separately for each eye. Presenting visual acuity was measured initially with the subject’s glasses (if worn). Visual acuity was measured without glasses if the subjects did not have eyeglasses with them at the time of the ophthalmic examination (adults who did not wear eyeglasses or adults who had eyeglasses but did not wear them habitually).
If the presenting visual acuity was <6/6, the examination was repeated with subjective refraction. If the refraction measurement could not be appropriately obtained, a pinhole-corrected acuity test was performed. Visual acuity was determined as the smallest line in which most E’s were positioned correctly; that is, 4 of 4 E’s correct at a given level of acuity or at least 5 of 6 E’s correct at a given level. Best corrected distance visual acuity was defined as the best of all measurements.
Definitions of blindness and visual impairment vary widely around the world. The World Health Organization has reported 65 different definitions of blindness used by clinicians, scientists, and governments.
10 In the present study, correctable visual impairment was defined as presenting visual acuity (naked eye if without spectacles and with distance eyeglasses if worn) in the better eye of <6/12 that improved to no impairment (≥6/12) after refractive correction. The cutoff of 6/12 was used because it is more representative of the visual needs of modern life, such as driving, and is comparable to that used in other studies.
5 11 12
Spherical equivalent (sphere +1/2 cylinder) was calculated from the best refractive correction. A spherical equivalent between −1.0 and +1.0 D was defined as emmetropia, less than −1.0 D as myopia, and greater than +1.0 D as hyperopia.
Spectacle coverage was defined in accordance with the Bangladesh survey
13 :
\[\mathrm{Spectacle\ coverage(\%)\ {=}\ met\ need/total\ need\ {\times}\ 100\%}\]
\[\mathrm{Total\ need\ {=}\ met\ need\ {+}\ unmet\ need.}\]
“Met need” was defined as the number of subjects who wore distance spectacles and had a visual acuity of <6/12 in the better eye without correction, but who achieved ≥6/12 in the better eye with their present distance spectacles. “Unmet need” was the number of subjects who did not wear spectacles and had an acuity of <6/12 in the better eye without correction, but could achieve ≥6/12 in the better eye with correction. We further included those who wore spectacles and had a visual acuity of <6/12 in the better eye, but could achieve ≥6/12 in the better eye with refractive correction. This represents the group with spectacles of inappropriate power.
Educational level was classified into two groups in this study: secondary education and below, high school and above. Marital status was dichotomized into married and single/separated/divorced/widowed. Personal medical history was investigated using a checklist. Hypertension, diabetes mellitus, cardiovascular disease, and stroke were defined as positive if the subject was previously diagnosed by a physician as having the disease.
Analysis was performed for subjects with correctable visual impairment compared with subjects experiencing no visual impairment. Independent variables evaluated included sex (male versus female), age (≥75 years versus 65–74 years), marital status (married versus single/separated/divorced/widowed), living status (living alone versus living with spouse/children/relatives/friends), self-assessed need of support service (yes versus no), educational level (secondary education and below versus high school and above), history of hypertension (yes versus no), diabetes mellitus (yes versus no), cardiovascular disease (yes versus no), stroke (yes versus no), history of contact of eye service (yes versus no), distance eyeglasses worn during examination (yes versus no), and refractive status (emmetropia versus hyperopia and emmetropia versus myopia).
Odds ratios (ORs) and 95% confidence intervals (CIs) were used to examine whether there was a statistically significant association between each of these independent variables and correctable visual impairment under univariate analysis. P < 0.05 was considered to be statistically significant.
To determine whether independent variables were predictive factors for correctable visual impairment after adjustment among variables, multiple logistic regression analysis was used to fit the best model for independent variables (all the variables analyzed in univariate analysis were included in multivariate models), with correctable visual impairment as the dependent variable.
Scoring of the SF-36 questionnaire was performed using the Rand 36-Item Health Survey (version 1.0) method. For each variable item, scores were coded, summed, and transformed to a dimensional score. Dimensional scores represent the average for all items in the particular dimension and range from 0 to 100, with a higher score being indicative of a better health status.
The relationship between correctable visual impairment and quality of life was evaluated. Because the scores of the eight SF-36 dimensions were not normally distributed, the Wilcoxon rank sum test was used to detect differences between participants with correctable visual impairment and those without visual impairment in the SF-36 dimensions separately. P < 0.001 was considered to be statistically significant here to reduce the likelihood of making a type I error due to multiple comparisons (P = 0.3 for detecting a statistically significant difference by chance when making eight concurrent comparisons).
Multiple linear regressions were used to fit the best model with the log of the scores of the eight dimensions of SF-36 as the dependent variables. Correctable visual impairment and all the other covariates (sex, age, marital status, living status, self-assessed need of support service, educational level, history of hypertension, diabetes mellitus, cardiovascular disease, stroke, history of contact with an eye service, distance eyeglasses worn during eye examination, and refractive status) were independent variables.
Statistical analysis was performed with commercial software (SAS ver. 6.12; SAS Institute Inc., Cary, NC).
Of the 2045 subjects, 1361 (66.6%) participated in both the questionnaire and eye examination. Six hundred seventy-seven (33.1%) subjects cooperated only for the household interview. Seven (0.03%) subjects could not be contacted after three attempts to visit the household. A comparison of demographic information and some of the variables in subjects with and without the eye examination revealed that the participating subjects were younger than those that refused to participate in the study (72.2 years vs. 74.3 years, t= 5.10, P < 0.001), were more likely to be male (χ2= 24.8, P < 0.001), and more educated (χ2 = 14.16, P < 0.001). There was no significant difference in the other variables (marital status and history of diabetes and hypertension) between the two groups.
Among the participants, the men were more likely to be married (χ2 = 175.44, P < 0.001), to have a higher educational level (χ2 = 175.61, P < 0.001), and to have had previous contact with an eye service than were the women participants (χ2 = 8.67, P < 0.01). There was no significant difference between the sexes in the other demographic variables.
The correlation of refractive status between the right and left eyes was high (0.70; P < 0.001). Most of the participants (43.1%) were in the emmetropic group. Of the participants, 17.3% were myopic and 39.6% were hyperopic in the right eye.
There were two subjects in whom visual acuity could not be measured because a visual acuity test could not be performed. Thirteen subjects were legally blind (best corrected visual acuity ≤20/200) and 86 had noncorrectable visual impairment (<20/40 to >20/200), according to the United States criteria. The presenting visual acuity was not obtained for 29 subjects. Therefore, data were analyzed from 1231 subjects.
The prevalence of correctable visual impairment was 9.55% (95% CI, 7.97%–11.13%). There were significantly more women than men with correctable visual impairment (χ2 = 11.41, P < 0.001). Of the subjects with correctable visual impairment, 48.8% presented with Snellen visual acuity of 6/15 in the better eye. The remaining subjects had a visual acuity range of 6/60 to 6/20.
Table 1shows the spectacle coverage of the participants. Overall, 127 participants needed spectacles (114 subjects) or a change of spectacles due to inappropriate power (13 subjects). There was a significant difference in spectacle coverage between the men and women (76.4% in men versus 63.9% in women; χ
2 = 8.06,
P < 0.01).
Of the 127 subjects with correctable visual impairment, 112 (88.2%) obtained an improvement of at least two Snellen lines after refractive correction, and 44 (34.6%) subjects obtained an improvement of at least 5 Snellen lines
(Table 2) .
Table 3shows the association between correctable visual impairment and the various independent variables. Correctable visual impairment was significantly associated with older age (≥75 years; OR, 3.05; 95% CI, 2.10–4.44), female gender (OR, 1.82; 95% CI, 1.26–2.63), and a history of stroke (OR, 2.08; 95% CI, 1.05–4.11). Having nonemmetropic eyes (both hyperopia and myopia) was significantly related to correctable visual impairment. Myopia (OR, 5.45; 95% CI, 3.31–8.95), however, was a higher risk than hyperopia (OR, 1.79; 95% CI, 1.14–2.82).
On the other hand, being married (OR, 0.54; 95% CI, 0.37–0.80), a higher level of education (OR, 0.51; 95% CI, 0.33–0.77), and wearing distance eyeglasses during the eye examination (OR, 0.29; 95% CI, 0.16–0.52) were protective factors for correctable visual impairment.
In the final multiple logistic regression analysis controlling for all covariates, older age (≥75 years; OR, 2.41; 95% CI, 1.56–3.70) and nonemmetropic eyes (myopia; OR, 6.80; 95% CI, 3.77–12.77 versus hyperopia; OR, 2.13; 95% CI, 1.29–3.51) were significantly related to correctable visual impairment. A higher level of education (OR, 0.52; 95% CI, 0.32–0.83) and wearing distance eyeglasses during the eye examination (OR, 0.23; 95% CI, 0.12–0.43) were protective factors for correctable visual impairment.
Comparison of the quality of life was performed between participants with correctable visual impairment and those without visual impairment. Those with a correctable visual impairment scored significantly lower in the physical functioning dimension (Wilcoxon rank sum = 63,991.5, P < 0.001). There was no significant difference between the two groups in the other seven dimensions.
In the final regression analyses controlling for all covariates
(Table 4) , those with a correctable visual impairment scored significantly lower on the physical functioning dimension than did those with no visual impairment (
t = −2.80,
P < 0.01). Factors contributing to a lower score in the physical functioning dimension of the SF-36 were older in age (
t = −3.63,
P < 0.001), were women (
t = −4.81,
P < 0.001), and had a history of diabetes (
t = −2.28,
P = 0.02) or stroke (
t = −3.60,
P < 0.001), and requiring supportive service (
t = −3.50,
P = < 0.001). Correctable visual impairment was not significantly related to the other seven dimensions of the SF-36 in the multiple regression analysis.
Our results indicate that 9.6% of the senior population in the Shihpai district have a correctable visual impairment. Older age and nonemmetropic eyes (especially myopia) were significantly related to correctable visual impairment, whereas a higher education level and wearing distance eyeglasses during the eye examination were protective factors. Moreover, correctable visual impairment was negatively associated with the physical functioning dimension of the SF-36.
The SEE Project,
12 which recruited residents aged ≥65 years in Salisbury, Maryland, reported that 5.6% of whites and 10.4% of blacks had correctable visual impairment. In that study, presenting binocular visual acuity rather than visual acuity of the better eye was used, potentially resulting in slightly better acuities. Our prevalence of correctable visual impairment was between that of the two racial groups represented in the SEE study.
The Tanjong Pagar Survey reported that 17.3% of Singaporean Chinese aged 40 to 79 years had an undercorrected refractive error, defined as an improvement of at least 2 lines of visual acuity in the better eye.
14 Visual acuity could be improved by at least 4 lines in 4.6% of their participants, which corresponds to the percentage in the present study.
In the Blue Mountains Eye Study (age, ≥49 years),
15 7.5% of participants had correctable visual impairment, 3.6% had noncorrectable visual impairment, and 88.9% had no impairment. In their 5-year follow-up, the percentages were 5.6%, 2.7%, and 91.7%, respectively. In both their baseline study and 5-year follow-up, similar risk factors were identified: older participants, living alone, use of community service, dependence on others for activities of daily living, history of heart disease, fair to poor self-rated health, myopia, and wearing distance eyeglasses during the eye examination. Protective factors were being married, being a homeowner, having a high-prestige job, gaining qualifications after high school and being a current driver.
Undercorrected refractive error was defined as improvement of at least 5 letters (1 line) in best corrected visual acuity in the Visual Impairment Project.
7 The undercorrected rate was 9.8% for all participants. Increasing age was the most important predisposing factor, 3% in the 40s age group and 29% in the 80s age group. Absence of distance correction was the second most important factor. Although the age of recruitment and criteria for correctable visual impairment was different from that in the present study, similar predisposing factors were noted.
The spectacle coverage of our subjects was much higher than that in Bangladesh (30 years and older).
13 With a visual acuity cutoff of 6/12, the spectacle coverage was 25.3%, which is in stark contrast to our level of 71.2%. In both studies, spectacle coverage was significantly higher in the men (30.2%) than in the women (20.9%). A study in Tehran
16 recruited citizens aged ≥5 years reported that the spectacle coverage rate was 66.0%, which is comparable to that in our study. In that study, the rate of uncorrected refractive error was 4.8%. The difference in the rate of uncorrected refractive error may be due to differences in recruitment age. That study identified older age, less education, and myopia as risk factors, which is consistent with the Tanjong Pagar Survey
14 and our study.
In the Baltimore Eye Survey (40 years and older),
4 54.0% of participants improved their presenting vision by at least 1 line after refractive correction and 7.5% improved at least 3 lines. The investigators noted that in both blacks and whites, a significant proportion of visual loss was due to inadequately corrected refractive error. The reasons for the large volume of undercorrected refractive errors, despite the ready availability of optometric and ophthalmic services, are not clear.
Lack of utilization of ophthalmic care for prevention and treatment has created the impression that loss of vision is expected with increasing age, and the idea that nothing can be done to improve the situation is prevalent among older persons,
17 particularly those who are less educated.
18 This may be one of the reasons that despite the easy accessibility to ophthalmic consultation in this metropolitan area, only approximately one third of our participants had contacted an eye service. Economic impetus might be another reason but since the implementation of the National Health Insurance Program in Taiwan in 1994, this factor should no longer be a barrier to the accessibility of ophthalmic services.
Our results demonstrated that the very elderly and the myopic group are at highest risk of having a correctable visual impairment. However, higher educational level and wearing distance eyeglasses during the eye examination were protective factors. There are several possible explanations for these findings. The more highly educated might be more health conscious and have regular ocular check-ups. In the Bangladesh Study,
13 hyperopes were more likely to wear eyeglasses. The Tanjong Pagar Survey
14 identified myopia as one of the risk factors for undercorrected refractive error. In our population, both hyperopia and myopia were predisposing factors for correctable visual impairment, with myopic individuals at higher risk. It may be because in myopic older persons, near vision is still mostly preserved and they may be content with clear near vision, even though far vision is compromised, and thus they would not be inclined to correct their refractive error. In hyperopes, however, both far and near vision are compromised. In addition to the decreasing accommodative capacity at this age, eyeglasses are necessary to achieve adequate visual acuity for their daily activities.
The impact of correctable visual impairment on the quality of life in older persons, especially in the physical functioning dimension deserves further evaluation. Because our survey was cross-sectional in design, it is plausible that poor physical functioning led to correctable visual impairment because of the inconvenience in accessing ophthalmic service for these older persons. It is also possible that both are related to a third unidentified factor. The SEE Project
12 noted that a binocular visual acuity worse than 20/40 has an impact on all the self-report measures of functional status. The Blue Mountains Eye Study
11 also found that subjects with presenting visual impairment had an independent impact on global health ranking in people younger than 80 years of age. A randomized trial of individuals aged 65 and older with uncorrected refractive error demonstrated clear benefits of eyeglasses and magnifiers on vision-specific quality of life.
19 In the intervention group, there were clear benefits in the perception of general, distance, and near visual acuity and mental health and well-being due to vision.
There were some limitations in our study. First, potential subjects who were institutionalized were not examined. Excluding inpatients, the paralyzed and disabled may have accounted for a disproportionate number of people with physical and/or visual impairment and removing them from the subject pool biased our results. Hence, the association between quality of life and correctable visual impairment should be greater than our results indicate.
Our participants were more likely to be men, younger, and more highly educated than were nonparticipants. Also, our results indicate that older persons and the less educated are more likely to have correctable visual impairment. Hence, the extent and impact of correctable visual impairment should be even greater than our results indicate.
Despite these limitations, this is one of the few community-based studies of the ophthalmic condition as well as the quality of life of older persons in Asia. This study was performed by professionally trained ophthalmologists in a well-equipped medical center.
Our results demonstrate that approximately 10% of the senior population in the Shihpai district has a correctable visual impairment. Thus, it is important to educate the public about the importance of regular examination and the possibility of improving visual acuity by wearing glasses.
Supported by Grants VGH 89-404-1, VGH 90-445-1 and VGH 91-382-1 from Taipei Veterans General Hospital, Taipei, Taiwan. This manuscript was awarded the Best Poster at the 20th Congress of the Asia Pacific Academy of Ophthalmology, 2005, Malaysia.
Submitted for publication June 7, 2006; revised November 5 and 18, 2006; accepted January 19, 2007.
Disclosure:
T.-M. Kuang, None;
S.-Y. Tsai, None;
W.-M. Hsu, None;
C.-Y. Cheng, None;
J.-H. Liu, None;
P. Chou, None
The publication costs of this article were defrayed in part by page charge payment. This article must therefore be marked “
advertisement” in accordance with 18 U.S.C. §1734 solely to indicate this fact.
Corresponding author: Pesus Chou, Institute of Public Health, National Yang-Ming University, Shih-Pai, Taipei 112, Taiwan;
[email protected].
Table 1. Spectacle Coverage of Participants
Table 1. Spectacle Coverage of Participants
| Spectacle Coverage | Male (%) (n = 807) | Female (%) (n = 523) | Total (%) (n = 1330) |
| Naked eyes with no visual impairment | 503 (62.3) | 287 (54.9) | 790 (59.4) |
| With glasses, no visual impairment (met need) | 197 (24.4) | 117 (22.4) | 314 (23.6) |
| Naked eyes with correctable visual impairment (unmet need) | 53 (6.6) | 61 (11.7) | 114 (8.6) |
| With glasses, with correctable visual impairment (change glasses) | 8 (1.0) | 5 (1.0) | 13 (1.0) |
| Noncorrectable visual impairment | 46 (5.7) | 53 (10.1) | 99 (7.4) |
Table 2. Visual Improvement after Refractive Correction
Table 2. Visual Improvement after Refractive Correction
| Number of Snellen Line Gained | Subjects, n (%) |
| ≥1 | 127 (100) |
| ≥2 | 112 (88.2) |
| ≥3 | 91 (71.2) |
| ≥4 | 61 (48.0) |
| ≥5 | 44 (34.6) |
Table 3. Univariate and Multivariate Analysis of Correctable Visual Impairment
Table 3. Univariate and Multivariate Analysis of Correctable Visual Impairment
| Variable | Correctable VI/No VI | Univariate Odds Ratio (95% CI) | Multivariate Odds Ratio (95% CI) |
| Age group | | 3.05* (2.10–4.44) | 2.41* (1.56–3.70) |
| 65–74 | 66/847 | | |
| ≥75 | 61/257 | | |
| Gender | | 1.82* (1.26–2.63) | — |
| Male | 62/701 | | |
| Female | 65/403 | | |
| Education | | 0.51* (0.33–0.77) | 0.52* (0.32–0.83) |
| Secondary school and below | 95/662 | | |
| High school and above | 32/441 | | |
| Married | 80/836 | 0.54* (0.37–0.80) | — |
| Not married | 47/267 | | |
| Refractive status (SE, †) | | | |
| Hyperopia | 52/460 | 1.79* (1.14–2.82) | 2.13* (1.29–3.51) |
| Emmetropia (reference) | 33/522 | 1.00 (reference) | |
| Myopia | 42/122 | 5.45* (3.31–8.95) | 6.80* (3.77–12.77) |
| Distance eyeglasses worn during eye examination | | 0.29* (0.16–0.52) | 0.23* (0.12–0.43) |
| Yes | 13/314 | | |
| No | 114/790 | | |
| Ever contact eye service | | 0.76 (0.50–1.17) | — |
| Yes | 31/329 | | |
| No | 93/755 | | |
| Hypertension | 57/495 | 1.01 (0.70–1.47) | — |
| No hypertension | 68/598 | | |
| Diabetes mellitus | 17/164 | 0.92 (0.54–1.58) | — |
| No diabetes mellitus | 103/916 | | |
| Cardiovascular disease | 32/279 | 1.06 (0.70–1.63) | — |
| No cardiovascular disease | 86/798 | | |
| Stroke | 11/48 | 2.08* (1.05–4.11) | — |
| No stroke | 116/1050 | | |
| Lives alone | 9/80 | 0.98 (0.48–1.99) | — |
| Not lives alone | 118/1024 | | |
| Requiring supportive service | 3/21 | 1.24 (0.37–4.22) | — |
| Not requiring supportive service | 124/1078 | | |
Table 4. Multiple Linear Regression on Log of Score of Physical Functioning Dimension
Table 4. Multiple Linear Regression on Log of Score of Physical Functioning Dimension
| Independent Variable | Dependent Variable: Log (Physical Functioning Score) | |
| Parameter Estimate | P |
| Age group (≥75 y vs. 65–74 y) | −0.06 | <0.001* |
| Gender (female vs. male) | −0.09 | <0.001* |
| Education (≤secondary education vs. ≥high school) | 0.02 | 0.27 |
| Marital status (married vs. not married) | 0.03 | 0.11 |
| Correctable visual impairment (yes vs. no) | −0.07 | <0.01* |
| Distance eyeglasses worn during eye examination (yes vs. no) | −0.03 | 0.08 |
| Myopia (myopia vs. emmetropia) | 0.04 | 0.09 |
| Hyperopia (hyperopia vs. emmetropia) | 0.03 | 0.07 |
| Ever use eye care services (yes vs. no) | −0.02 | 0.16 |
| Hypertension (yes vs. no) | −0.02 | 0.19 |
| Diabetes mellitus (yes vs. no) | −0.05 | 0.02* |
| Cardiovascular disease (yes vs. no) | −0.05 | 0.07 |
| Stroke (yes vs. no) | −0.13 | <0.001* |
| Lives alone (yes vs. no) | −0.05 | 0.12 |
| Requiring supportive services (yes vs. no) | −0.20 | <0.001* |
OlshanskySJ, CarnesBA, CasseslCK. The aging of the human species. Sci Am. 1993;268:46–52.
[CrossRef] [PubMed]AtteboK, IversRQ, MitchellP. Refractive errors in an older population. The Blue Mountains Eye Study. Ophthalmology. 1999;106:1066–1072.
[CrossRef] [PubMed]DandonaR, DandonaL. Refractive error blindness. Bull World Health Organ. 2001;79:237–243.
[PubMed]TielschJM, SommerA, WittK, et al. Blindness and visual impairment in an American urban population. The Baltimore Eye Survey. Arch Ophthalmol. 1990;108:286–290.
[CrossRef] [PubMed]KleinR, KleinBE, LintonKL, et al. The Beaver Dam Eye Study: visual acuity. Ophthalmology. 1991;98:1310–1315.
[CrossRef] [PubMed]AtteboK, MitchellP, SmithW. Visual acuity and the causes of visual loss in Australia. The Blue Mountains Eye Study. Ophthalmology. 1996;103:357–364.
[CrossRef] [PubMed]LiouHL, McCartyCA, JinCL, et al. Prevalence and predictors of undercorrected refractive error in the Victorian population. Am J Ophthalmol. 1999;127:590–596.
[CrossRef] [PubMed]World Health Organization. Programme for the Prevention of Blindness and Deafness: Global Initiative for the Elimination of Avoidable Blindness. 1997;1–7.WHO Geneva.
TsaiSY, HsuWM, ChengCY, et al. Epidemiologic study of age-related cataracts among an elderly Chinese population in Shihpai, Taiwan. Ophthalmology. 2003;110:1089–1095.
[CrossRef] [PubMed]World Health Organization. Blindness information collected from various sources. Epidemiol Vital Stat Rep. 1996;19:437–511.
WangJJ, MitchellP, SmithW. Vision and low self-rated health: the Blue Mountains Eye Study. Invest Ophthalmol Vis Sci. 2000;41:49–54.
[PubMed]WestSK, MunozB, RubinGS, et al. Function and visual impairment in a population-based study of older adults. The SEE Project. Invest Ophthalmol Vis Sci. 1997;38:72–82.
[PubMed]BourneRRA, DineenBP, HuqDMN, et al. Correction of refractive error in the adult population of Bangladesh: meeting the unmet need. Invest Ophthalmol Vis Sci. 2004;45:410–417.
[CrossRef] [PubMed]SawSM, FosterP, GazzardG, et al. Undercorrected refractive error in Singaporean Chinese Adults. The Tanjong Pagar Survey. Ophthalmology. 2004;111:2168–2174.
[CrossRef] [PubMed]ForanS, RoseK, WangJJ, et al. Correctable visual impairment in an older population: the Blue Mountains Eye Study. Am J Ophthalmol. 2002;134:712–719.
[CrossRef] [PubMed]FotouhiA, HashemiH, RaissiB, et al. Uncorrected refractive errors and spectacle utilization rate in Tehran: the unmet need. Br J Ophthalmol. 2006;90:534–537.
[CrossRef] [PubMed]LandesR, PopayJ. “My sight is poor but I’m getting on now”: the health and social care needs of older people with visual problems. Health Soc Care. 1993;1:325–335.
LindesayJ, JaggerC, HibbettMJ, et al. Knowledge, uptake and availability of health and social services among Asian Gujarati and white elderly persons. Ethn Health. 1997;2:59–69.
[CrossRef] [PubMed]ColemanAL, YuF, KeelerE, et al. Treatment of uncorrected refractive error improves vision-specific quality of life. J Am Geriatr Soc. 2006;54:883–890.
[CrossRef] [PubMed]