Definitions

AWARENESS OF AGE RELATED EYE DISEASE

People who were not previously diagnosed with one or more of the three conditions were asked if they had heard of cataract, glaucoma, and AMD (yes/no).

PREVIOUS DIAGNOSIS OF AGE RELATED EYE DISEASE

A respondent was classified as being previously diagnosed with cataract, AMD, or glaucoma, if they self reported that a doctor had diagnosed then as having any of the three eye conditions. Previous diagnosis was assessed as the potential to confound the relation between knowledge, attitudes, and self care practices.

FAMILY HISTORY OF AGE RELATED EYE DISEASE

Participants were questioned on their family’s history of age related eye disease, cataract, glaucoma, and AMD. Family members comprised parents and siblings.

CORRECT KNOWLEDGE OF EYE DISEASE

During the interview, respondents previously diagnosed as having an eye disease, or who indicated that they were aware of the disease in question, were asked to describe it. Acceptable, correct definitions were provided by co-author (HRT) and are presented below.

Cataract:

lens opacity; film over the eye; causes vision loss/blindness; affects the elderly; causes blurred vision;

Macular degeneration:

problem related to the retina; causes vision loss/blindness; central focusing problem; affects the elderly;

Glaucoma:

pressure problem related to the eye; causes vision loss/blindness; causes tunnel vision; affects the elderly; problem at the back of the eye.

 People who provided knowledge on one or more of the three eye conditions were compared with those who did not provide any information on one or more of the three eye conditions.

ATTITUDES

Participants were asked additional questions on their attitudes on the prevention and treatment of blindness. Responses were dichotomised into those who reported blindness prevention or treatment and support as their highest priority compared with the other conditions and those who did not.

SELF CARE PRACTICES

All participants were asked the year of their last visit to an eye practitioner—that is, either an ophthalmologist or optometrist. The period of the most recent visit to an eye service was grouped as 2 years or less, 3 or more years, or never.

The following categories were used: age was grouped into decades, language spoken at home as English or other language; country of birth as Australia or other; family history as a family member with a diagnosis of cataract, AMD, glaucoma, or none; location as rural compared with urban and education level was grouped into primary or secondary, trade, or tertiary.

For people who could not speak English, family members or employed interpreters translated the questions and responses given.

Participants were not prompted to possible responses. Data were recoded and analysed using sas (Cary, NC, USA). Statistical methods included the χ² test for comparing groups; odds ratios and 95% confidence intervals were calculated using logistic regression techniques. The results of the analyses were considered statistically significant when p<0.05.

Results

A total of 1711 people participated in eye examinations in the first five sample areas of the Melbourne VIP and 1473 participants from the four sample areas of rural Victoria. This represented an 89% participation rate from the total of 5520 residents enumerated in the private household census. In metropolitan Melbourne, although non-English speaking people were less likely to participate (OR: 0.61; CI: 0.48–0.77), there were no other significant differences between participants and non-participants and between participants and the Melbourne and Australian populations.10 In rural Victoria, there were no significant differences between participants and non-participants. The participants ranged in age from 40 to 103 years and 53% were female.

A total of 2443 (77%) people reported that they were aware of one or more of the three eye conditions. The majority of people provided knowledge of cataract (74%) (Table 1). Many respondents confused glaucoma with other eye conditions: 10% described it as cataract or a growth over the eye; 4% described it as trachoma, and 1% linked it with diabetes; 3% of people who stated an awareness of AMD confused the disease with cataract. Seven per cent of people who had knowledge of cataract, 6% who had knowledge of glaucoma, and 11% of people who had knowledge of AMD provided general information on the diseases—that is, the condition causes blindness/vision loss or affects the elderly.

To evaluate the association of specific sociodemographic characteristics among those who provided correct knowledge about age related eye disease, several regression models were constructed (Table2).

A multivariate logistic regression model was constructed using all of the significant factors from the univariate analyses (Table 2). When the individual variables were adjusted for, the significant predictors of correct knowledge of eye disease were: age (younger), sex (females), higher levels of formal education, a recent visit to an eye practitioner, and English spoken at home. Contingency table analyses are presented (Table 3).

A subsample of 1557 participants was asked questions to determine their attitudes to the prevention of total blindness. Overall, 25% of the sample indicated that they would prevent total blindness first compared with cancer of the bowel (36%), Alzheimer’s disease (24%), schizophrenia (8%), or heart disease (7%). The univariate analysis assessing the association between those who gave blindness prevention their first priority and specific sociodemographic factors highlighted that older people were less likely to regard blindness as a high priority (Table 4).

The subsample of participants were then asked their attitudes on the treatment of total blindness. Nearly two thirds (60%) of the sample reported that they would treat total blindness first compared with paralysis on one side of the body as a result of stroke (16%), loss of speech as a result of a stroke (15%), total deafness (4%), and amputation of an arm (4%). A univariate analysis assessed the characteristics associated with attitudes towards blindness treatment and a multivariate analysis performed (Table 4).The significant predictors of positive attitudes towards blindness treatment were a recent visit to an eye practitioner (within the past 2 years); younger age, correct knowledge of eye disease, and speaking English at home (Table 4).

Contingency table analyses indicated that 57% of people who spoke English at home considered blindness treatment a first priority compared with 30% of people who spoke another language at home; 58% of people with correct knowledge specified treatment as the priority compared with 48% of people who did not have any knowledge of age related eye disease; and 47% of people over the age of 70 considered visual impairment the important priority compared with 53% of people under the age of 70.

The third stage of the analysis was to determine factors that may influence self care practices or the regular utilisation of eye services. The distribution of optometric and ophthalmic service utilisation was similar in both areas (data not shown) so we grouped the urban and rural cohorts together. Overall, 1953 (61%) of the population sample had visited an eye practitioner, either an ophthalmologist or optometrist within the past 2 years compared with 1232 (39%) who had done so 3 or more years ago or never.

Again, a multivariate regression model was constructed after the univariate analyses (Table 5). The significant predictors of self care practices were a previous diagnosis of an age related eye disease, age, sex, knowledge of age related eye disease, and English spoken at home. When the potential confounding variable previous diagnosis of cataract, glaucoma, and AMD was removed from the multivariate analysis, there was found to be no significant confounding effect whatsoever.

Contingency table analyses indicated that 85% of people with a previous diagnosis of cataract, AMD or glaucoma visited an eye practitioner within the past 2 years compared with 58% who did not have a previous diagnosis; 53% of people over the age of 60 years visited an eye practitioner in the past 2 years compared with 38% of people 3 or more years ago; 63% of females had visited an eye practitioner in the past 2 years compared with 59% of males; and 62% of people who spoke English at home had a recent visit to an eye practitioner compared with 52% of people who spoke another language.

The final stage of the analysis was to determine whether a combination of knowledge of any of the age related eye disease and positive attitudes towards the prevention and treatment of total blindness would influence self care practices. However, an interaction between correct knowledge and attitudes with a recent visit to an eye practitioner was not found (OR: 1.15; 95% CI: 0.97–1.37) (Fig 1).

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Figure 1

Tree of knowledge and positive attitudes and their association with use of eye services.

Discussion

This investigation examined the knowledge, attitudes, and self care practices of individuals in an urban population sample. To our knowledge, no other study has investigated the influence of location (urban compared with rural communities) or the potential role of family history of age related eye disease and KAP. The study was undertaken to identify information that could enhance a public health campaign designed to reduce the prevalence and incidence of the three most common age related eye diseases. The results may help target specific groups within the community.

Few studies have investigated the relation between KAP and age related eye disease.11-13 The results of the current study indicated that the majority of people had correct knowledge of one or more of the three eye conditions specified; however, this was mainly attributable to respondents providing a lay description of cataract—that is, “a film over the eye”. There were serious deficiencies in respondent knowledge of both glaucoma and AMD, with 20% of respondents confusing glaucoma and AMD with other eye conditions. This lack of knowledge is consistent with other studies conducted in Germany and the United States.10 11

In this study, younger people, females, those with higher levels of education and those speaking English at home were more likely to have a better understanding of age related eye disease. Similar predictors of correct knowledge have been demonstrated in other KAP studies conducted both in other health areas as well as eye disease.9 10 14 Pronzato et al 14 also found that women and patients with a higher education level were more knowledgeable about their disease. Michielutte et al 12 found that females and people who reached higher levels of education had the highest levels of knowledge of glaucoma and diabetes. Researchers of the Lighthouse National Survey10 found that the youngest, wealthy, and more educated respondents were more likely to be informed about visual impairment.

Older people did not appear to consider blindness prevention as a particularly high priority. This may have been attributable to the design of the questions themselves. The choices offered in the question on the prevention of disease included mortality-type conditions such as heart disease and cancer of the bowel as well as morbidity-type conditions, such as total blindness. Verbrugge et al 15 analysed the impact of several conditions on adults and found that life threatening conditions such as heart disease and malignant neoplasms received greater community prominence despite the fact that non-fatal conditions such as visual impairment, arthritis, and hearing impairment had a significant long term impact on both the individual and the community.

Other studies10 16 17 have indicated that knowledge of a condition or disease can positively influence self care practices. In this study, knowledge of age related eye disease appeared to influence positive self care practices.

Women were more likely to participate in regular eye health care. This is consistent with the previous reports of women’s overall perception of health care and the propensity for women to seek out preventive health care compared with men.18 Interestingly, people who had correct knowledge of age related eye disease were more likely to participate in regular utilisation of eye services; however, a combination of both correct knowledge and attitudes that considered prevention and treatment of total blindness as the highest priority did not appear to interact with self care practices. Further research is required to establish the reasons why people participate in ophthalmic eye services on a regular basis. It could be that fear of going blind or losing vision predicts people’s behaviour. Alternatively, it may be the individual’s income predicts behaviour. Constraints on income may limit self care practices.

There are limitations to this study that need to be considered when interpreting the results. Firstly, self report measures can result in recall bias; however, in any study, inaccuracies are unavoidable when self report measures form part of the study design. In addition, the concepts that we were attempting to assess may be influenced by current prevalence rates of disease in the community and state of the art in disease definition over time. With an aging community, people are more likely to develop age related eye conditions; and with new diagnostic equipment, we are more likely to diagnose the diseases earlier.

Notwithstanding these limitations, the results of this study suggest that there is limited knowledge among those at greatest risk of suffering from vision loss and visual impairment as a result of age related eye disease. Educating the community on glaucoma, AMD, and to a lesser extent cataract will be an important first component in the promotion of preventative ophthalmic care towards a reduction of visual impairment in the community. Redressing the lack of knowledge associated with common eye disease poses a challenge for public health professionals. To maximise their effectiveness, innovative information programmes must be focused on groups that are at greatest risk of losing their vision. In the first instance, information programmes that highlight the consequences of age related eye disease on the individual, the benefits of regular eye examinations, and appropriate treatment could be undertaken by general practitioners. General practitioners are important agents of health behaviour change as they have the opportunity to affect, at a population level, at least 80% of the population in Australia each year.19 General practitioners, therefore, are well placed to target the aging community, particularly males, people from non-English speaking backgrounds, and those with limited formal education.