El marco legal de la formación de los maestros

As mentioned in the introduction, the leading causes of vision impairment in older people are ARMD, glaucoma, cataracts and diabetic retinopathy. Some studies have indicated that the cause of impairment can be correlated with one's reaction to the loss. For example, Upton, Bush and Taylor (1 998) undertook a study on the impact of vision loss on 80 older male veterans with diabetes in comparison to those whose vision loss was caused by other aetiologies such as ARMD, glaucoma and trauma. Results indicated that diabetes and recent loss of vision were more strongly correlated with problems with adjustment and with daily functioning. The degree of vision impairment was not a strong stressor variable. Thus, it may have been the aetiology of the loss, or factors associated with the loss, that had more meaning to individuals than the impact the loss had on daily functioning.

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Later, Keeffe, McCarty, Hassell and Gilbert ( 1 999) incorporated in their study the degree of vision impairment, as well as cause of impairment in relation to activity and participation, and measures of emotional reaction to vision loss. Their study involved the development and testing of a measure to describe and measure disadvantages caused by impaired vision. Ninety-five Australians with impaired vision were involved, with vision acuities of 20/200 or worse after correction. Most participants were women, and most reported ARMD as the cause of their vision impairment. Although the age range was 1 8-9 1 , the mean age was 67 years. Questions relating to "handicap" were derived from a pool of vision-related quality of life questionnaires. For this study, handicap was defined as "limitation on activity experienced by an individual relative to their own needs, or those of peers or society" (p. 1 84). The major concerns of those older people with impaired vision who helped to develop the measure were ability to drive and emotional problems associated with diagnosis of an eye condition. Also measured were domains of personal and household care, social and consumer interactions, mobility and leisure or work.

Major findings from this study by Keeffe et al. (1 999) were that those with better vision reported less difficulty with all measured activities. Nevertheless, degree of vision impairment was not related to degree of emotional reaction to vision loss. Degree of vision impairment was related to difficulty with daily activity domains of leisure and work, mobility, social and consumer interactions and household and personal care. Type of vision impairment was considered as well. Those with ARMD reported greater difficulty in social and consumer interactions whereas those with glaucoma and

retinopathies had greater emotional reactions to vision loss. Cause of vision impairment, even when controlled for age, was found to be significant in predicting

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mobility difficulties. Keeffe et al. concluded that vision does have a role in the nature and degree of activity and participation, but other factors also can create difficulties for those with vision impairments and these, too, must be explored. Other studies have also found that degree of vision impairment was not associated with 1ife satisfaction

(Kleinschmidt et. aI, 1 995).

Severity of vision impairment has been the focus of numerous studies in relation to activity and independence for older people. Standard clinical measures of vision include acuity and degree of field. Estimates of the prevalence of vision impairment in older people vary greatly, according to the definitions used for vision impairment. Vision impairment is determined, based on an established difference from the norm.

Eligibility for services from the RNZFB requires acuity of 6/24 (20170) or less in the better eye with correction or field restriction of 20 degrees or less, with normal fields being about 1 80 degrees. In the U.S., legal blindness is defined as having an acuity of 20.200 (6/60) or less in the better eye with correction, or field restriction to 20 degrees or less. A broader category of severe vision impairment is often defined in terms of functional norms, as an inability to read regular newspaper print, even with corrective lenses. The New Zealand census regarded vision impairment in functional terms, i.e. inability to read newsprint with glasses, or clearly see the face of someone across the room (Statistics New Zealand, 200 1 a). No matter how estimates are made, it is clear that incidence of significant vision impairment increases with age, as many causes of vision loss are age-related (Branch et al., 1 989; Havlik, 1 986; Rosenbloom, 2000).

2 -Reviewing the Literature and Reviewing the ICF Model Brenner, Curbow, Javitt, Legro and Summer (1 993) found links between severity of vision impairment and decreased physical and mental functioning in 1 ,02 1 older adults. Participants were all receiving ophthalmological treatment at the time of the survey and were aged 50+. Vision was measured with the Snellen acuity chart, and this acuity was translated into a binocular acuity measure. Visual function was assessed in interview questions related to reading, recognising people, seeing steps and seeing cracks in the footpath. These researchers also found that improvements in visual functions

accompanied improvements in quality of life (QOL), community participation, ADL, mental health and life satisfaction, especially in those with cataracts. This was primarily a study on the effect of improved vision on QOL, but the links between severity of impairment and functioning are relevant to this review.

Elfervig (1 997) introduced the variable of life satisfaction in relation to severity of vision impairment in a study with 80 adults with impaired vision aged 65+. Elfervig examined functional independence and life satisfaction for those with ARMD. Those eligible for the study had visual acuities of no better than 20/200. The Instrumental Activities of Daily Living Scale was used to assess eight categories of daily functioning (telephoning, shopping, food preparation, housekeeping, laundry, transportation use and managing money). The Life Satisfaction Index-A was used to measure satisfaction with life. This is an I 8-item life satisfaction scale, administered by the researcher in a face­ to-face interview, with dichotomous responses (satisfied, dissatisfied). Results indicate that severity of vision impairment was related to both functional independence and life satisfaction, even when controlled for age and gender. The greater the severity of vision impairment, the less satisfied they were with life . The greater the severity of vision impairment, the more limitations older adults had in activities of daily living,

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"specifically shopping, laundry and handling finances." (p. v). Duration of vision impairment was not related to functional independence nor to satisfaction with life for this group, nor was the type of onset of vision loss (gradual or sudden), related to functional independence. The relationship between functional independence and life satisfaction was not tested in this study.

Recent onset of significant vision loss has been indicated to have profound negative effects on psychosocial functioning of older adults (Kleinschrnidt, 1 999). Kleinschmidt used both quantitative and qualitative methods to study differences in response to vision loss among older people. Although this study involved only 1 2 participants, a useful finding is that initial reactions to vision loss were nearly universally negative. Only after time did positive affect emerge as predominant for the 1 2 participants who were rated as "successfully adjusted" to vision loss. Prior life experiences, internal and external resources were identified as factors correlated with good adjustment to vision loss. Kleinschmidt's study was not of normative adjustment but of exemplary

adjustment. The sampling procedures used were not random, but selected by the author based on subjective researcher judgment of the participant having adjusted well, and the participants were homogeneous in terms of socio-economic status and gender ( 1 0 of 1 2 were women). A comparison of this group o f well-adjusted adults to those viewed as adjusting "poorly" or "adequately" to vision loss would, perhaps, reveal additional useful information. In contradiction to Kleinschmidt' s findings, and the results of the other studies reviewed in this section, other studies have found no link between type of vision impairment, age at onset of significant vision impairment or time since onset to social support or quality of social support in the older popUlation (Hersen et aI., 1 995; Reinhardt & Blieszner, 2000).

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In summary, over recent decades research has emerged investigating activity, independence, some measures of QOL and life satisfaction, and the impact of other health impairments as well as type, severity and duration of vision impairment for older people. Some studies have found that the differences in activity or participation

measures between the groups of people with impaired vision and sighted older people were not as large as expected. In fact, Crews and Campbell (200 1 ) found that people with vision impairments were similar to those without such impairments on measures of activity participation. Those with vision impairments did report, however, a greater desire for more social activities than did their sighted peers. The authors concluded that the area required further investigation. In contrast to these findings, it has been found that decreased participation in social and recreational activities and dependence in activities of daily living were more frequently due to vision impairment than to other health impairments (Burack -Weiss, 1 999). Other factors warrant further investigation to explore the impact of impairment on activity, independence and life satisfaction, including contextual factors such as personal and environmental variables.