Demographic Characteristics of the Vision-Disabled Elderly

Transcription

1 Demographic Characteristics of the Vision-Disabled Elderly David B. Elliott,* Mia Trukolo-Ilic,^ J. Graham Strong,^ Rodger Pace,\ Ann Plotkin,j and Pauline Beversj- Purpose. To profile certain demographic features of the low-vision population in Ontario, Canada. Methods. Sixty-six optometrists or optometry centers, 8 ophthalmologists, and 23 Canadian National Institute for the Blind rehabilitation worker teams were recruited to the study. They were required to report on their low-vision examinations during a 3-year period. Results. Reports from 4744 low-vision examinations were received. Of the patients examined, 71% were over age 65 (subsequently called seniors or elderly), and 55% were over age 75. Ninety percent of all the patients lived in households and 10% lived in institutions. Seniors made up 71 % of the patients living in households and 88% of the patients living in institutions. Most of the seniors were women (65%), and 57% had functional limitations in addition to low vision, most commonly limitations in mobility, hearing, or agility. Age-related maculopathy was the primary diagnosis in 75% of seniors, and the most common secondary diagnosis was cataract (46%). The main objective for most elderly low-vision patients was to gain improvement in personal reading (75%). Conclusions. The vast majority of low-vision patients were elderly, the largest number being 75 to 84 years old. When older senior low-vision patients (^85 years) were compared with younger seniors (65 to 74 years), the older seniors were more likely to be women, more likely to have additional functional limitations, more likely to live in an institution, and more likely to have age-related maculopathy and cataract. Whether some elderly low-vision patients may be helped by cataract surgery needs to be determined. Invest Ophthalmol Vis Sci. 1997; 38: JL he main objective of this study was to profile certain demographic features of the low-vision population in the province of Ontario, Canada. This study overcame some of the limitations of previous low-vision clinic reports 1 " 7 by providing detailed demographic data from a large sample of patients who had been examined by nearly 100 service providers scattered throughout the province. In addition to the generally collected data (age, sex, diagnosis, and low-vision aids used), data regarding secondary diagnosis, primary and secondary patient objectives for the examination, and additional functional limitations were also collected. From the *Department of Optometry, University of Bradford, Bradford, West Yorkshire, United Kingdom, and the f Centre for Sight Enhancement, School of Optometry, University of Waterloo, Ontario, Canada. Supported by grants from the Ontario Ministry of Health Rehabilitation Technology Research Fund (grant W2974) and from the Centre for Sight Enhancement (University of Waterloo). Submitted for publication October 15, 1996; revised February 12, 1997, April 29, 1997, andfuly 14, 1997; acceptedfuly 14, Proprietary interest category: N. Reprint requests: David B. Elliott, Department of Optometry, University of Bradford, Bradford, West Yorkshire, BD7 1DP, United Kingdom. These data still may not reflect the exact demographics of low-vision patients in Ontario because they describe only those who went for examination in a lowvision or ophthalmic practice. Given the high percentage of elderly persons (>65 years old) in the lowvision population, and the fact that this will increase further in the coming years, results relating to the senior patients are discussed in most detail. Because the elderly population of Canada and other developed countries is also aging, with dramatic increases in the population older than 85 years, the demographics of this older seniors population is also described and compared with that of the younger seniors population (65 to 74 years). METHODS The tenets of the Declaration of Helsinki were followed, informed subject consent was gained, and ethical approval was granted by the University of Waterloo Office of Research Investigative Ophthalmology & Visual Science, November 1997, Vol. 38, No. 12 Copyright Association for Research in Vision and Ophthalmology

2 Demographics of Vision-Disabled Elderly 2567 Participants Clinical low-vision services in Ontario, Canada, are provided by licensed practitioners (optometrists and ophthalmologists). The Ministry of Health's Assistive Devices Program (ADP) authorization process makes no distinction between these two professional groups. Vision rehabilitation workers employed by the Canadian National Institute for the Blind (CNIB) also provide low-vision rehabilitation services in cooperation with licensed practitioners. For a patient to become registered with ADP, he or she must receive an eye examination from an optometrist or ophthalmologist before any low-vision assessment can be carried out by CNIB workers. Participants for the study were recruited using a direct mailing solicitation to all licensed optometrists (approximately 900) and ophthalmologists (approximately 400) in the province for whom contact information was available. All rehabilitation workers from around the province were identified and contacted through the Ontario Division of CNIB. All participants were required to confirm licensure in the province of Ontario; to attend one of the regional introductory workshops; to be willing to provide lowvision assessment and authorization services according to ADP policies; to complete simple data report forms as required by the research protocols; to participate in an annual survey of registered professionals; and to attend 1-day low-vision review workshops. Many of the optometrists and ophthalmologists contacted had not been providing low-vision services and had no interest in doing so. Sixty-six optometrists, 8 ophthalmologists, and all 23 CNIB rehabilitation teams were recruited and completed the requirements outlined above. The regional distribution of participants was widespread and consistent with the general population distribution in Ontario. Essentially all existing low-vision service providers in Ontario participated in the study. In addition, many optometrists and ophthalmologists who were previously providing few or no low-vision services agreed to take part in the study and subsequently began to provide low-vision services. In return, all participants were provided with an extensive low-tech low-vision kit and low-vision review workshops at no cost. The low-vision kit consisted of an array of low-vision devices having equivalent viewing powers ranging from +4 D to +24 D. In addition to the optical low-vision aids, the kit also included various tints, filters, visual acuity charts, and so forth and had a total worth of approximately $2000 CAN. CNIB vision rehabilitation workers received a basic kit consisting of nonprescription low-vision devices that allowed them to perform a triage service. CNIB workers were restricted in their prescribing options for ADP, particularly regarding spectacle-mounted devices and spectacle prescriptions. Data Collection Forms All 97 participants agreed to complete report forms describing each of their low-vision patient encounters over the study period from November 1991 to March Data forms were completed once all related services had been finished and a follow-up, monitoring, or recall schedule established, and participants were asked to complete only one form per patient. Only one report was accepted for each patient, and that was the first report received and entered into the database. The report forms were divided into two sections, general information and ophthalmic information. General characteristics included individual identifier (Ontario Health Insurance Plan number, date of birth, and practitioner number); demographic information (sex and living arrangement [household or institution]); and other functional limitations, using the categories and definitions of disability stated in the Canadian postcensus surveys on disabilities, the Health and Activity Limitation Surveys. 8 For the ophthalmic characteristics section of the form, a categorical classification system was created to be consistent with other blindness and low-vision demographic data reported in the literature. 1 " 7 Other types of ocular disease classifications that have been used in the literature (e.g., the International Classification of Diseases, 9th revision) yielded a very high level of disorder specificity. The 17 diagnoses used were age-related maculopathy (ARM), albinism, cataract, congenital cataract, corneal disorders, degenerative myopia, diabetic retinopathy, glaucoma, injury, juvenile macular degeneration, nystagmus, optic atrophy, retinal detachment, retinopathy of prematurity, retinitis pigmentosa, stroke, and other. Study participants were asked to record the primary and up to two secondary diagnoses. A categorical classification of each patient's objectives for the low-vision examination was used, including all the categories reported previously in similar low-vision clinic studies. 2 ' 3 The objectives listed were school work, vocational reading, personal reading, daily living activities, watching TV, hobbies, mobility or independent travel, glare control, and other. Clinicians were asked to record each patient's primary and secondary objectives. Right and left eye distance visual acuities were recorded. Practitioners were asked to record whether their examination indicated the presence of any significant visual field defect, using the categories central scotoma, hemianopia, and restricted to 20, 10, or 5. Practitioners were not asked to indicate if they had made an assessment of the visual field or the type of visual field assessment used. Participants were asked to record the visual aid prescribed using the relevant ADP number taken from

3 2568 Investigative Ophthalmology & Visual Science, November 1997, Vol. 38, No. 12 TABLE l. Demographic Characteristics of All Patients Characteristic Sex Female Male Age (years) Children (2-14) Adults (15-64) Seniors (65+) Living arrangement Household Institution Additional disability Mobility Agility Hearing Speaking Other Unknown Number (n = 4744) (%) ADP manual. A category was also set up to indicate when refractive correction was provided. The forms were designed to minimize the need for time-consuming coding of data. The mean time required to complete the form was less than 5 minutes. Even so, the form was ophthalmically biased, and future studies could include important demographic questions regarding race or ethnicity, marital status, education, and socioeconomic status. The data were entered into an ORACLE database at the University of Waterloo run under a UNIX network and were analyzed using the STATIT statistical package. General Characteristics Demographic characteristics of the sample are summarized in Table 1. Given the amount of data, only information thought to be of interest is discussed here. Given the high percentage of the elderly within this population, and the fact that this will probably increase in the coming years, only results relating to the senior patients are discussed in detail. Age groups were defined using Statistics Canada's categories: children (0 to 14 years of age), adults (15 to 64 years), and seniors (65 and over; also called the elderly in this report). 8 Seniors were divided into three age groups: younger seniors (65 to 74 years), intermediate seniors (75 to 84 years), and older seniors (85 and over). 8 ' 9 The age of the patients ranged from 2 to 110 years, with a median age of 77 years. Most patients were in the older age group: 71% of the total were seniors and 55% were over age 75. Of all patients reported, there were 61% women and 39% men. This aggregate statistic conceals an imbalance: among younger patients (<35 years), there were more men than women (56% versus 44%). Among patients aged 35 and over, there were more women (63%) than men (37%). The imbalance was even more evident in patients over age 75, of whom 67% were women and 33% were men. The age distribution of patients by sex is shown in Figure 1. Services for vision-impaired persons were provided by three service groups. Seventeen percent of patients were seen at optometrists' and ophthalmologists' offices (subsequently termed low-vision prac- RESULTS Subjects in the study were patients who visited one of the 97 practitioners for a low-vision assessment and whose report forms were returned to the Centre for Sight Enhancement (CSE). There were 4954 report forms returned. Some report forms that were missing vital data (e.g., patient's date of birth) were discarded, producing a final sample of 4744 patients. There were several reasons why data may have been lost or not reported. We suspect that some participants failed to submit data forms for all their lowvision patients, but there is no way of objectively estimating the extent of this noncompliance. Some data were lost because of faulty or missing vital data on the report forms (approximately 210), and some were lost because of mistakes in recording ADP device codes. ADP codes for low-vision aids changed during the study; therefore, low-vision aids were simply grouped and reported in generic device categories Age group (years) FIGURE l. Age distribution of vision-disabled patients by gender (plotted as a percentage of the total of 4744).

4 Demographics of Vision-Disabled Elderly Age group (years) 85 + CNB Practitioners FIGURE 2. Comparison of the age distributions of vision-disabled patients seen by the three service providers: Canadian National Institute for the Blind (CNIB), Centre for Sight Enhancement (CSE), and optometrists and ophthalmologists in general practice (practitioners). The percentage distribution is shown for each individual service provider. titioners). Twenty-four percent were seen at the CSE at the University of Waterloo. Fifty-six percent were seen at the CNIB, where patients were examined mainly by rehabilitation workers trained for low-vision assessment, or sometimes by a visiting optometrist. In 129 cases (3%), the report form listed no practitioner number. The age distribution by the three service groups is shown in Figure 2. The age distribution of the patients seen by the low-vision practitioners was very similar to that in patients seen by the CNIB rehabilitation workers, with the vast majority of the patients seen being elderly (78% and 83%, respectively). However, the age distribution of the patients seen at the CSE was bimodal: only 41% of the CSE patients were seniors, and 47% were under age 35. Ninety percent of patients lived in households and 10% in institutions. Seniors made up 17% of the patients living in households and 88% of the patients living in institutions. This is in agreement with age distributions of living arrangements of disabled persons in Ontario. 10 Not surprisingly, many of the elderly patients living in institutions were older seniors (48%) and women (70%), and many of the elderly patients living in households were intermediate seniors (49%) (Fig. 3). Additional functional limitations were present in 55% of all patients and 57% of all seniors. Of the vision-disabled elderly with other functional limitations, 83% lived in households and the rest (17%) in institutions. There was a higher average age for the institutionalized population for seniors both with and without additional functional limitations. In addition, the average age of both populations with other disabilities was higher than the average age of both populations without other disabilities. There were 36% older CSE seniors, 47% intermediate seniors, and 17% younger seniors with other disabilities living in households (Fig. 4). In the institutionalized population, there were 57% older seniors, 37% intermediate seniors, and 6% younger seniors with other functional limitations. Mobility (29%), hearing (28%), and agility (27%) limitations were the most common disabilities among vision-disabled elderly patients living in households (n = 1507). The same disabilities were also the most prevalent among the institutionalized elderly patients (n = 399; 32% mobility limitations, 29% agility limitations, and 24% hearing limitations). All other categories (i.e., other, unknown, and speaking limitations) accounted for 17% of the elderly patients with limitations other than seeing living in households and for 15% of the elderly patients with other limitations living in institutions. Ophthalmic Characteristics The distribution of the primary ocular diagnoses of the elderly patients is presented in Figure 5 (there were 19 missing senior cases). For the elderly population, it is not surprising that ARM was the leading cause of low vision (75% of the senior patients). Other primary ocular diagnoses included other causes (10%), glaucoma (6%), diabetic retinopathy (5%), and cataract (4%). With advancing age, ARM became more prevalent: it was present in 58% of younger seniors and in 84% of older seniors. Diabetic retinopathy, however, became far less prevalent with advancing age: the prevalence was 13% in so 40 Household Institution Age group (years) FIGURE 3. Living arrangements of vision-disabled elderly patients by age group (plotted as a percentage of the total of 3342).

5 2570 Investigative Ophthalmology & Visual Science, November 1997, Vol. 38, No. 12 Agility Hearing Mobility U Other Speaking Unknown a Age group (years) Diabetic ret. 4,57% Glaucoma 6.01% Agility Hearing Mobility E3 Other D Speaking Unknown cataract became more prevalent: 47% of younger seniors had cataract as a secondary diagnosis versus 59% of intermediate and 60% of older seniors. Visual acuity levels ranged from 6/6 to "count fingers," with a median of 6/46. Because most of the data were obtained from CNIB centers, where visual acuities are often taken with the patient's habitual correction (his or her own spectacles) rather than optimal refractive correction, these data may not represent optimal visual acuity values. The visual acuity data from the CNIB centers were compared with those from the practitioners using the chi-square test. The comparison showed significantly worse visual acuities of patients seen at the CNIB centers, widi 59% having a visual acuity of 6/60 or less (compared with 46% in the practitioner group) and only 22% having a visual acuity better than 6/30 (compared with 35% in the practitioner group). Cataract 3.53% ARM 75.49% Other 10.39% ARM 8.28% Age group (years) FIGURE 4. Additional functional limitations of vision-disabled elderly patients living in households (upper plot; plotted as a percentage of 1507) and in healthcare institutions (lower plot; plotted as a percentage of 399) by age group. younger seniors, 3% in the intermediate group, and only 1% in older seniors. The prevalence of glaucoma remained approximately the same for all age groups (6% for younger and intermediate seniors, 5% for older seniors). Of all the elderly patients with a primary diagnosis, 37% of men and 40% of women had a secondary diagnosis (see Fig. 5). Older seniors had significandy more secondary diagnoses than younger seniors (34% versus 18%). Of all the elderly with secondary diagnoses, 57% had cataract, 13% had glaucoma, and 8% had ARM (see Fig. 5). As the age of the seniors increased, Glaucoma 13.27% Cataract 56.90% Other 21.55% FIGURE 5. Pie chart of the distribution of primary (upper chart; n = 3342) and secondary (lower chart; n = 1304) diagnoses for vision-disabled elderly patients. Any category with a score <2.5% is not shown individually and is added to the "other" category.

6 2571 Demographics of Vision-Disabled Elderly Daily living activities 14.45% Personal reading 75.17% Mobility 4.60% ^0* Hobbies 9.76% Glare control 10.79% Watching TV 17.73% v^c /. Olher 3.23% T \ ^<&ZA ^*< ^ ^ ^ ^ ^ ^ y' Daily living activities 33.20% Persona! reading FIGURE 6. Pie chart of the distribution of primary (upper chart; n = 3335) and secondary (lower chart; n = 1455) objectives for vision-disabled elderly patients. Any category with a score <2.5% is not shown individually and is added to ihe "other" category. Visual field data are not presented because these results were somewhat unreliable. Because there was no "not measured" category, it was impossible to determine if visual fields were not measured or not reported. Of those reported (41%), 89% indicated a central scotoma, which was predictable given the high prevalence of ARM. Pie charts of the distribution of the elderly patients' primary and secondary objectives for the lowvision examination are shown in Figure 6 (there were 39 missing senior cases). By far the most common primary objective for elderly patients was personal reading (75%, or 62% of all patients). The second most common primary objective was to obtain help with the vision-oriented performance of daily living activities (14%). There was a slight age trend within the results from the elderly patients, with the prevalence of personal reading as a primary objective increasing in prevalence from younger (71%) to intermediate (77%) and older seniors (76%). The distribution of the secondary objectives among senior patients varied to a greater degree (see Fig. 6). The goal of improving performance of daily living activities was the most prevalent (33%); other prevalence rates were personal reading (21%), watching TV (18%), glare control (11%), hobbies (10%), and mobility and independent travel (5%). Analysis of the age distribution of the patients' secondary objectives revealed some interesting findings. The objective of improving vision for watching TV had a slight downward trend with age: 20% of younger seniors, 17% of intermediate seniors, and 16% of older seniors wanted improved vision for watching TV. The highest increase in an objective with advancing age among seniors was for glare control: 8% among younger seniors, 11% among intermediate seniors, and 13% among older seniors. Interest in mobility and independent travel decreased slightly with aging, from 6% among younger seniors to 4% among older seniors. Low-vision aids were prescribed in 76% of cases for seniors and refractive correction in 12%. No help was provided in 11% of senior cases. Because CNIB rehabilitation workers cannot refract or prescribe a refractive correction, their low-vision therapy prescribing is limited and differs greatly from that of optometrists and ophthalmologists. The percentages of seniors receiving the various therapies from the CNIB (n = 2205) were low-vision aids 79%, refractive correction 2%, and none 13%. The same information from the practitioner group (n = 623) was low-vision aids 77%, refractive correction 74%, and none 6%. For the CNIB, hand and stand magnifiers were by far die most commonly prescribed ADP low-vision aid (70% of all aids). They were also the most commonly prescribed low-vision aid in the practitioner group, but at a much lower percentage level (43%). Spectacle-based low-vision aids (high distance vision corrections, spectacle magnifiers/microscopes, and spectacle-mounted telescopes) made up 38% of prescribed aids from the practitioner group and 9% of prescribed aids from the CNIB. DISCUSSION Previous studies on low-vision demographics have used information from one or a few low-vision clinics,1"7 from questionnaire reports, as a subset of general health status,11"14 or from blindness registration data. The latter two methods are used mainly to provide prevalence figures for partial sight and blindness; data from low-vision clinics are used to provide detailed information regarding the type of patient and service provided. However, all three types of information have been used to estimate the distribution of low vision with age and sex. This information is of great importance when estimating the need for future resources for the low-vision population, given the

7 2572 Investigative Ophthalmology & Visual Science, November 1997, Vol. 38, No. 12 aging of the population. Data from the survey method is limited in the amount of detail and the accuracy of the information gained. In Canada, two comprehensive postcensus surveys on disabilities have been conducted, the Health and Activity Limitation Surveys (1986 and 1991). 12 Only two questions related to vision were asked to identify those with visual disability: "Do you have trouble reading ordinary newsprint, with glasses or contact lenses if usually worn?" and "Do you have any problems recognizing a face across the room with glasses or contact lenses if usually worn?" l2>13 In other surveys, only the question related to reading problems has been used Another serious disadvantage of these data is that they are derived from perceived (self-reported) vision problems. The advantage of surveys is that the numbers of participants are usually large (e.g., 5335, , ), so that there is a much lower probability of sampling error. The disadvantage of the third method (blindness registration) is that many people may be vision-impaired but not legally blind. In addition, many eligible people may remain unregistered because of the emotional connotations of the "blindness" label or because of the lack of services in rural areas. Immigrants could be underrepresented because cultural and language barriers make it difficult for them to gain access to services. In 1993, Robinson 15 estimated that the actual number of persons who were eligible to be registered as blind or partially sighted in the United Kingdom was four times the number who were officially registered. Data from low-vision clinic studies are often collected from small and sometimes preselected populations of patients from isolated low-vision clinics; thus, their value is limited because of possible sampling errors. For example, reports have been based on a sample of 185 patients whose best visual acuity with conventional aids did not exceed 20/70 in the better eye or whose maximal diameter of the visual field did not exceed 20 2 ; 200 patients 3 ; 200 patients who were supplied with low-vision aids on their first visit to the clinic 5 ; 172 patients who were supplied with low-vision aids for near vision 6 ; and 218 patients. 7 The advantage of these studies is that they provide reliable and usually detailed ophthalmic information. This study overcame some of the limitations of previous low-vision clinic reports by providing detailed demographic data from a large sample of patients who had been examined by nearly 100 service providers. Demographic Information In previous low-vision clinic studies, the age distributions of younger patients, up to age 50, were very similar to those found here (see Fig. 1). Of all the patients, 8% were 0 to 14 years old and 21% were 15 to 64 years old. For the 0-to-l 4-year-old age group, the female to male ratio was 80:100; for the 15-to-34-yearold age group, it was 82:100. Part of this difference can be explained by the fact that there are more males than females in this age group in the general population of Ontario (95:100) 16 ; also, sex-linked congenital ocular diseases are more common in males. 7 We compared the prevalence of seniors in our population with the prevalence found in earlier studies. The percentage of low-vision clinic patients >70 years old, as approximated from Figure 8 of Leat and Rumney, 7 is as follows: 56% J ; 55% 4 ; 57% 5 ; 66% 7 ; the present study, 66%. There were more elderly patients in the Leat and Rumney study 7 and in this study than in earlier studies. This is not because Canada has more elderly people than other countries; on the contrary, Canada's population is relatively young compared with other developed countries However, it is experiencing the worldwide pattern of demographic aging. 17 Older studies contain younger populations (the data in the Hill and Cameron study 4 were collected from 1970 to 1980; Robbins' 1 data are from 1977 to 1982), but newer studies reflect the aging of the population and therefore contain older populations (Leat and Rumney's 7 data are from 1984 to 1988, and our data are from 1991 to 1994). The number of seniors in Canada grew by 128% between 1961 and 1991 from 1.4 million to 3.2 million (representing 11.6% of Canada's population). By 2031, the proportion of seniors (>65 years) is expected to exceed 20%, or more than 8 million. 19 Similar demographic trends are expected to occur in Ontario. 20 In addition to the aging of Canada's population as a whole, the elderly population of Canada is also aging. Between 1961 and 1991, the number of persons age 85 and older increased by 250%, compared with only 128% for seniors as a whole. 19 This trend is continuing, so we have also described the demographics of this older seniors group and compared the results with those from the younger senior group to provide a further indication of the probable demographics of the low-vision population in the future. Another difference between this study and others was that most other reports provide data from only one large low-vision clinic. 1 ' 4 ' 7 Because this was a multicenter study, easier access for patients was provided. The subsequent reduction in traveling distances and costs may have caused a relative increase in the number of seniors presenting for eye examinations. Another factor that may make these results different from those of other studies is the healthcare benefits available to vision-disabled patients in Ontario. During the study period (and at present), the government paid up to 75% of the cost of any low-vision aids prescribed for vision-impaired residents through the ADP. In addition, both primary and supplementary eye examinations were provided free of charge to all

8 Demographics of Vision-Disabled Elderly 2573 residents through the Ontario Health Insurance Plan. In many other provinces and countries, a major part of the financial burden is carried by the patient. 11 Because of the substantially reduced average incomes of seniors, 21 this support may have removed any monetary constraints preventing them from obtaining lowvision devices. Given that this easier access to services and removal of monetary constraints may particularly help the elderly to obtain low-vision services, these data may represent the best estimate to date of the demographics of the elderly population with low vision. In this study, there were substantially more women among all seniors (the ratio was 194:100 for the 65- and-up age group). This may also be explained in part by the trend in the general population of the same age (140:100). 16 Other factors are that senior women are relatively older than senior men, various age-related ocular diseases may be more prevalent in women, 22 and women report greater morbidity and use of health services than do men. 23 ' 24 Ophthalmic Information In all low-vision clinic reports from developed countries that provide diagnostic information, ARM is the major presenting condition.'' 4 ' 5 ' 7 The percentages are similar: 38%'; 39% 4 ; 45% and 54% 5 ; 48%. 7 The percentage of low-vision patients with ARM as a primary diagnosis in the present study was 56% of all patients; ARM was also present as a secondary diagnosis in 7% of cases. The high percentage of ARM in this study reflects the relatively large number of older patients in the sample. ARM was present in 58% of younger seniors, 79% of intermediate seniors, and 84% of older seniors in this study. The increasing prevalence of ARM with age has also been found in large epidemiologic studies, such as the Framingham 22 and the Beaver Dam 25 eye studies. Cataract was present as a primary diagnosis in a small percentage of patients. These patients were unable or unwilling to have cataract surgery, perhaps because of poor general health, advanced age, or general reluctance. 1 Cataract was by far the most common secondary diagnosis. The prevalence was 46% of the 1134 patients reported as having a secondary diagnosis. Although most studies have not reported secondary diagnoses, Leat and Rumney 7 also found that cataract was the most common secondary diagnosis, at 41% of their low-vision clinic patients. Once again, this is related to the high prevalence of older patients in the studies. The prevalence of age-related cataract increases substantially with age, 1 ' 7 ' 2225 and cataract was shown to be increasingly prevalent as a secondary diagnosis among the older seniors (from 47% in young seniors to 60% in older seniors). There may be some link between this and the increase with age among the senior population who listed glare control as a secondary objective (from 8% to 13% for the young and older senior groups, respectively). The most common combination of primary and secondary diagnoses is, not surprisingly, ARM and cataract. Modern surgery has made cataract extraction a relatively simple and very successful operation. This raises the important question of whether the many low-vision patients with cataract and ARM (19.3% of all patients in this study, ~20% in the Leat and Rumney study 7 ) would benefit from cataract surgery. It is likely that cataract surgery would improve such patients' visual acuities and the "hidden" vision losses of contrast sensitivity and disability glare. 26 Surgery is also likely to lead to improvements in response to magnification, reading ability, and mobility orientation, among other functional vision tasks. 27 With the number of people with the combination of ARM and cataract likely to continue to increase with the aging of the population, this requires further investigation to assess the improvement that may be possible with cataract surgery, and whether it is possible to predict which patients would benefit. Diabetic retinopathy became less prevalent with advancing age. Among all patients, the peak prevalence of diabetic retinopathy was in the 55-to-64-yearold group (25% of the patients in this age group, or 61 patients). The prevalence was 13% in younger seniors (98 patients), 3% in intermediate seniors (50 patients), and only 1% in older seniors (10 patients). The reduction in percentage terms is caused in part by the increases in numbers of low-vision patients with ARM being examined. However, the results suggest that after age 84 there are fewer diabetic patients alive, or perhaps they are unable or unwilling to attend an examination. The CNIB visual acuity data were significantly worse than those reported by low-vision practitioners. These differences could be due to uncorrected refractive errors in some CNIB patients, because many studies have shown that visual acuity can be improved by measuring it with the best spectacle correction rather than the one that a patient presents. 7 ' 28 ' 29 This is particularly true for elderly persons 29 and low-vision patients. 728 However, every CNIB client had a registration assessment with an optometrist or ophthalmologist before a CNIB visit to determine the need for refractive change. In addition, rehabilitation workers were instructed about how to screen for significant refractive error using a pinhole acuity method. Other possible causes for the difference include sampling differences (perhaps the CNIB examined patients with worse visual acuities than other practitioners for some reason, perhaps registration criteria) or differences in visual acuity measurement (possibly differ-

9 2574 Investigative Ophthalmology & Visual Science, November 1997, Vol. 38, No. 12 ences in chart type or luminance or measurement technique 30 ). By far the most common primary objective in seniors for the low-vision examination was personal reading (75%, or 62% of all patients). Two previous reports have found similar percentages (68% 2 and 79% 3 ). Generally, this can be accomplished using lowtech devices, and these services can be provided by the ophthalmic clinician in general practice. Studies have shown that a high proportion of patients can benefit from a low-vision kit consisting of simple lowvision aids (~75% 5 ; 77% 6 ; 68% 7 ). The advantages of having low-vision services in general practice are easier accessibility for patients and a reduction in the number of people seeking help from already overloaded specialist low-vision centers. Low-vision aids were prescribed in 76% of cases for seniors, refractive correction was prescribed in 12%, and no help was given in 11% of cases. The percentage of seniors receiving a refractive correction from the CNIB (n = 2205) was 2%. These were presumably data from the centers that work with an optometrist or an ophthalmologist. The seniors examined by the practitioner group (n = 623) were prescribed a refractive correction in 74% of cases. Approximately half of these (38%) were spectaclebased low-vision aids (high distance vision corrections, spectacle magnifiers, spectacle-mounted telescopes). The remainder were either refractive corrections needed for optimal use of their low-vision aid, or new spectacles. Only 9% of prescribed aids from the CNIB were spectacle-based low-vision aids, presumably from the centers that worked with optometrists and ophthalmologists. Given that most low-vision patients examined in Ontario were seen by the CNIB, the trend for optometrists and ophthalmologists working in CNIB centers should be encouraged. Our results present a picture of the most typical low-vision examinations. Of the 4744 people seen in the study, 71% were over age 65 and 55% were over age 75. Most of these elderly people were women: 65% and 67% of those over 65 and over 75 years of age, respectively. Most seniors (57%) had functional limitations in addition to low vision, most commonly limitations in mobility, hearing, or agility. ARM was the primary diagnosis in 56% of the total cases and in 75% of seniors. Personal reading was the most common primary objective for low-vision examination (75% of all senior patients). The fastest-growing low-vision group is older seniors. With increasing age (shown by differences between younger and older seniors), the percentage of women increased, patients had additional functional limitations (particularly those living in institutions), patients had ARM as a primary diagnosis, and patients were more likely to have a secondary diagnosis, most often cataract (which may explain why older seniors were more likely to have a secondary objective of glare control). Key Words age-related maculopathy, demographics, low vision, low-vision aids References 1. Robbins HG. The low-vision patient of tomorrow. Aust JOptom. 1978; 61: Kleen SR, Levoy RJ. Low-vision care: Correlation of patient age, visual goals, and aids prescribed. Am J Optom Physiol Opt. 1981;58: Schwartz M. Low-vision patient populations: A comparative statistical analysis. Optom Monthly. 1982;73: Hill AR, Cameron A. Pathology characteristics and optical correction of 900 low-vision patients. In: Woo GC, ed. Loiu Vision: Principles and Applications. 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