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REVIEW ARTICLE
Factors related to the use of magnifying low vision aids: a scoping review
Marie-C
eline Lorenzini
a,b
and Walter Wittich
a,b
a
School of Optometry, University of Montreal, Montreal, QC, Canada;
b
Centre de Recherche Interdisciplinaire en R
eadaptation de Montr
eal
m
etropolitain, Montreal, QC, Canada
ABSTRACT
Background: The decision process around the (non-)use of assistive technologies is multifactorial. Its
determinants have previously been classified into personal,device-related,environmental and interventional
categories. Whether these categories specifically apply to the use of magnifying low vision aids was
explored here, using this classification.
Methods: A scoping review (Embase, MedLine, Cochrane, ERIC ProQuest, CINAHL, NICE Evidence, Trip
Database) was conducted to summarize the extent, range, and nature of research regarding the catego-
ries that are associated with low vision aid (non-)usage. A combination of key words and MeSH terms
was used based upon the identified core concepts of the research question: low vision,assistive technol-
ogy and adherence. Inter-rater reliability for the selection process was considered acceptable (kappa ¼
0.87). A combination of numerical and qualitative description of 21 studies were performed.
Results: Studies report high variability rates of people possessing devices but not using them (range:
2.3–50%, M ¼25%, SD ¼14%). We were able to replicate the conceptual structure of the four categories
that had previsouly been identified with other devices. Age, diagnosis and visual acuity demonstrated
contradictory influence on optical low vision aids usage. Change in vision, appropriate environment, con-
sistent training, patient’s motivation and awareness of low vision services, emerged as contributor factors
of use.
Conclusion: This review provides evidence that clinicians should not rely on traditionally available clinical
factors to predict device use behavior. Worsening vision and low motivation appear as predictors of
device nonuse and should be considered from the clinician’s point of view. Education about potential
facilitating factors and promotion of innovative care are strongly encouraged.
äIMPLICATIONS FOR REHABILITATION
Investigation of the factors predicting (non-)use of magnifying low vision aids is important. These
findings can help clinicians to identify patients with a higher risk of non-use of low vision aids as
well as provide evidence for interventions designed to improve use.
Knowledge of low vision services and types of magnifying low vision aids available to patients
appears as fundamental in the process of device use and needs to be supported by more educational
programs.
Psychological factors predicting (non-)use of low vision aids need to be considered in the choice of
rehabilitation and follow-up strategies by a multidisciplinary team, focusing more in mechanisms of
adaptation and patient’s motivation.
Training intensity should play a central role in the development of innovative intervention programs
to reduce device abandonment.
ARTICLE HISTORY
Received 20 June 2018
Revised 5 March 2019
Accepted 6 March 2019
KEYWORDS
Visual impairment; assistive
technology; magnification;
optical aid; adherence;
abandonment
Introduction
The ability to be living independently in their own home and
community has been reported as a major priority by individuals
with a disability [1]. Independent living is strongly encouraged by
health providers and policy makers in order to reduce social
expenses [2]. In this context, assistive technologies might be con-
sidered as tools facilitating disability self-management to maintain
independence and quality of life. Technology users want to be
able to use the device to the best of their ability; however, in
reality, acceptance of assistive technologies may be challenging.
In recent decades, given rapid technological development and
advancement, several studies have been performed in the field of
assistive technology (non-)use and have found that the decision-
making process of whether a person with a disability uses or
abandons their aids is likely multi-factorial [3–5]. In the specific
context of low vision, rehabilitation can be associated with
improved visual ability and an increase in functional status. Just
like other assistive technologies, low vision aids aim to increase
autonomy and enhance quality of life. The prescription of magnifi-
cation devices is one of the most common forms of intervention
[6,7]. Magnifiers are commonly handheld, head-mounted devices
or spectacles with convex lenses to magnify objects and intend to
facilitate the reading of small print at near or of details at far [8].
With the growing aging population, it is expected that the
CONTACT Marie-C
eline Lorenzini marie-celine.lorenzini@umontreal.ca School of Optometry, University of Montreal, 3744, Jean-Brillant, Montr
eal, Qu
ebec H3C
3J7, Canada
Supplemental data for this article can be accessed here.
ß2019 Informa UK Limited, trading as Taylor & Francis Group
DISABILITY AND REHABILITATION
https://doi.org/10.1080/09638288.2019.1593519
number of individuals with a visual impairment increases over the
coming decades [9]. It is urgent to gain a better understanding of
the mechanisms explaining the (non-)use of low vision aids, in
order to improve their success rate, the benefits gained, and their
cost-effectiveness. (Non-)use is a complex subject to study
because many factors are likely to be involved. It is well known
that, to gain the maximum benefit from low vision aids, device
users require manual dexterity and motivation [10]. However, our
knowledge about (non)-use rates and the factors specifically
related to the (non-)use of magnifying low vision aids
remains limited.
The reasons why clients with low vision may or may not
choose to utilize their low vision aids can vary widely and the
variability among reports of device abandonment is large.
Without distinguishing among low vision aid types, 84.5% of devi-
ces prescribed were still used (defined by reported as helpful or
used in the past year) by individuals with low vision in the U.S.
Department of Veterans Affairs [11]. In contrast to this high usage
rate and without distinction among low vision aid types, only
20% of their patients participating in a hospital-based low vision
program used their low vision aids frequently (a term not defined
by these authors) [12].
An overview of the determinants of assistive technology non-
use in general has previously been classified into four categories:
reasons related to the individual (e.g., depression or anxiety), to
the device itself (e.g., device weight or size), to the user’s environ-
ment (e.g., perception of stigma), and reasons related to the inter-
vention with the device (e.g., absence of technical support)
[13,14]. Using the same paradigm, it is probable that some of
these same categories common to adherence and the assistive
technology field are also associated with the (non-)use of magni-
fying low vision aids. The investigation of the factors predicting
nonuse of low vision aids is important. Such insights can help
clinicians to identify patients at higher risk of device abandon-
ment, and can provide evidence for interventions designed to
improve adherence. Moreover, to the best of our knowledge, no
other review has so far focused on factors related to magnifying
low vision aids use. Therefore, we decided to conduct a scoping
review on factors related to magnifying low vision aids (non-)use,
building on an existing classification of assistive technology non-
use in general.
Materials and methods
Here, we conducted a scoping review, instead of a systematic
review, in order to rapidly map and analyze the extent and nature
of studies about magnifying low vision aids. This approach has
previously been enhanced by healthcare researchers to provide
increased relevance to the clinical environment [15], and is espe-
cially appropriate in specific practice areas of research for which
only a limited amount of information has been published [16]. For
our team, this was the first step in a series of studies exploring
factors related to discontinuation of head-mounted displays, a
new class of magnifying low vision aid where device non(-use)
has not yet been explored. Following the systematic step-wise
methodology laid out by Arksey and O’Malley [16], their guide-
lines were used to examine and summarize the volume, range,
and nature of research activities and findings regarding categories
of factors associated with magnifying low vision aid usage. We
followed this 5-step process, which required us to a) identify the
research question, b) identify relevant studies, c) select inclusion
and exclusion criteria, d) chart the data and e) collate, summarize,
and report the results.
Identify the research question
Previously, four categories of factors relevant to device use have
been identified: they are personal,AT-related,linked to the user’s
environment and intervention-related [13]. The same categories
have also been associated with adherence to medical interven-
tions. Thus, this scoping review answers the following question:
Are these previously identified categories of factors, that have
been shown to be related to device use in general, also associ-
ated with the use of magnifying low vision aids?
Identify relevant studies
Searches were conducted using the following online databases:
Embase, MedLine, Cochrane, ERIC ProQuest CINAHL, Trip Database
and NICE Evidence, limited to English and French but without
limitation on publication dates. The databases were searched up
to October 2018 and each database was queried since its earliest
available date. The starting point (year) of Embase search was
1974, 1946 for MedLine, 2005 for Cochrane, and for CINAHL, Eric
ProQuest, NICE Evidence and Trip Database « all dates » option
was selected. A combination of key words and MeSH terms was
used (see Supplementary Tables S1 for MedLine; S2 for Embase;
S3 for Cochrane; S4 for Eric ProQuest; S5 for CINAHL; and S6 for
Gray literature research strategies), and based upon the identified
core concepts of the research question: (1) Low vision; (2)
Assistive technology; and (3) Adherence. The three concepts were
searched individually and were then combined together: Low
vision AND Assistive technology AND Adherence. The main inves-
tigator (MCL) and a research assistant independently screened
titles and abstracts, and then full-text articles against the eligibility
criteria (see below). Inter-rater reliability (kappa) was calculated
for agreement between the two screeners when sorting articles,
(first sample extracted from the titles and second sample
extracted from abstracts and entire article) and was considered
acceptable with a kappa value of 0.87.
Select inclusion and exclusion criteria
Through an iterative process with the literature about (non-)use
of low vision technologies, inclusion and exclusion criteria were
defined. Different inclusion criteria were applied between the first
and second screening, whereby articles that were not about low
vision aids were excluded during the first screening and articles
that were not about magnifying low vision aids and that did not
address (non)-use were excluded during the second screening. It
was difficult to find the relevant literature about magnifying low
vision aids in the initial research because “magnification”is not a
MeSH term; therefore, the search terms were chosen to be more
global to include all literature on low vision aids. Once the search
was complete, a refinement was implemented to exclude all
articles on non-magnifying devices during the second screening.
For the purpose of this study, the full-text review included
studies focusing on (1) low vision, (2) magnifying aids and (3)
(non)-use, regardless of research methodology. Magnifying low
vision aids refer to all systems enabling an enlargement of the
image, with or without optical components or refractive system,
whatever their distance of use and activities for which they are
intended. The category of low vision aids studied here includes
telescopic devices for distance tasks; handheld magnifiers and
stand magnifiers (e.g., closed circuit television systems) for near
tasks; and head-mounted-displays for both near and distance
tasks. Other systems not involving optical lenses but enlarging
the image, such as software integrated into a desktop or tablet
2 M-C. LORENZINI ET AL.
computer or smartphone were also included. The terms
“technology use”in this study was defined in various ways,
including adoption, adherence, acceptance or compliance. In par-
allel, “technology nonuse”here refers to abandonment, rejection,
underutilization, non-acceptance or non-adherence. The popula-
tion of interest consists of individuals with low vision without
restriction of age or visual pathologies. Literature about magnify-
ing low vision aids consisting of both peer-reviewed articles and
gray literature where (non)-use was central to the assessment
(main or secondary objective) were selected. In contrast, this
scoping review excluded studies involving sensory substitution or
mobility (e.g., cane or sound tools), as well as articles in which
only satisfaction or performances with magnifying low vision aid
components were the focus. A flow chart of the study exclusion
process is shown in Figure 1. The terminology “patients”was used
for individuals with low vision as it globally refers to health care
and is consistent and suitable for a rehabilitation context.
Charting the data
A charting form was developed by the first author to retrieve the
following data from the selected studies: author(s), year of publi-
cation, methodology, design, population, sample size and charac-
teristics of the participants, type of magnifying low vision aids,
(non-)use measurement, usage rate, theoretical frameworks and
categories of factors related to magnifying low vision aids use
(see Supplementary Table S7).
Collating, summarizing, and reporting the results
By incorporating the guidelines published by Colquhoun et al.
[15] as well as Sandelowski [17], the first author conducted a
qualitative and numerical description, whereby the quantitative
analysis focused on the characteristics of the studies (year of pub-
lication, design, sample/population). A qualitative description
presents data to answer the scoping review question. The four
previously presented categories of personal, device-related, envir-
onment and intervention were initially chosen [13,14]. However, if
a new category should emerge, based on information that would
not fit these existing four categories, it would be reported as a
new category. Then, each time an item was identified in articles
selected, it was placed in one of the four pre-determined catego-
ries in the appropriate column of the charting form.
Results
General findings
Study characteristics
The publication dates of the 21 selected studies ranged from
1974 and 2017. Observational studies (e.g., chart reviews or clin-
ical service descriptions) represented 86% while 14% were inter-
vention studies. Cross-sectional data collection was most frequent,
representing 62%, compared to 38% for using a longitudinal
design. Two randomized controlled trial were identified. Sample
size varied between n ¼11 and n ¼343.
(Non-)usage rate
Studies on (non-)use of magnifying low vision aids exhibited high
variability rates of participants owning/having devices available
but not using them (range: 2.3% - 50%, M ¼25%, SD ¼14%). It
is important to highlight that results from separate studies cannot
be directly compared, in part, because these studies did not focus
on the same devices, they defined (non-)use in different ways,
and measured it differently and at different moments in time.
Thus, to attempt to present the results in a more cohesive way,
low vision aids were categorized according to the working dis-
tance that characterizes their use. While studies focusing on low
vision aids in general reported a non-usage rate ranging from
14.6% to 36% (M ¼21.9, SD ¼7.7) [11,18,19], those involving
mainly near low vision aids exhibited a nonuse rate between
2.3% and 46.72% (M ¼20.5, SD ¼10.6) [8,10,20–28], whereas the
one study using distance low vision aids recorded a non-usage
rate of 50% [24]. Some of the studies indicated that distance low
vision aids were characterized by a very high rate of rejection as
compared to near low vision aids. For instance, one study using
closed-circuit television systems recorded a very good acceptance
rate but telescopes were characterized by a very high rate of
rejection (non-specified) [27].
Proportionally, the most prescribed low vision aids were for
near tasks. For example, one of the studies reported that 89% of
their patients were issued with low vision aids to assist near
vision, whereas only 4% patients were issued with distance low
vision aids, while 7% were issued with both [10]. Interestingly,
one study explored the usage of near devices, which are the most
abandoned; of the 33% of the near devices that were never used,
53% were hand-held, 28% were spectacle-mounted and 19%
were stand magnifiers [10]. As mentioned above, the definition
used by the authors to describe the (non)-use is important. For
this scoping review, a range of definitions used to characterize
(non)-use was established that are discussed in the next section.
Definition of (non-)use.
The clearest question that defined (non-)use of magnifying low
vision aids was asking participants: “Have you used the device?”
or specifying: “Have you used your devices consistently”[26,p.30].
Initial search within Embase, MedLine, ERIC ProQuest,
CINAHL, Trip Database, NICE Evidence
n = 2324
Articles for first screening
(Titles and Abstracts)
n = 1993
Articles for second screening
(Full-texts)
n = 237
Articles excluded because
they were not about
low vision aids
n = 1756
Articles excluded because
they were not about
magnifying low vision aids
n = 46
Duplicates excluded
n = 331
Selected articles
n = 21
Articles excluded because
(non)-use was not studied
n = 170
Figure 1. Flow chart of study selection process.
MAGNIFYING LOW VISION AIDS 3
In general, actual use was defined as a binary variable (yes/no
question) [20,28,29]. In one study, assistive technology use was
measured as the reported total number of devices used, based on
a given list of devices, wherein the authors aggregated all the
information into a sum score [30]. Some authors applied a more
refined and precise definition of (non-)use whereby device aban-
donment could be defined as no-use in the past three months [8]
or in the past year [31], or as interrupted usage during the past
year [31]. Nonuse was defined as irregular use averaging less than
twice per month [18] and as no use in the previous four weeks
[21]. Quantitative details referred to: how long the device was
used [22], the frequency of use [8,10–12,18–21,23,26–28,32,33],
the duration of use [8,11,20,21,23,26,27] at one time [20], per day
[23,31] or the longest time of continuous use [21], the last time a
device was used [11], or the average use [26]. Implementing a
more functional approach, participants were asked to manipulate
the device to prove that they continued using it [22]. Demirkilinc
et al. [28,p.982] used the definition of Nilsson et al. [34]of“not
treatment success”as a condition “when the patient does not
find an aid beneficial and does not use it to solve one or more
visual problems”. More comprehensively, the use of low vision
aids for reading was categorized at several levels of success
whereby the determination of levels involved 4 factors: the
degree of helpfulness in the reading task, the frequency of use,
the duration of use, and the improvement in reading ability [11].
In the same way, Rosenbloom [25] defined usage as the extent to
which a low vision patient continues to use a low vision aid and
the extent of its use in his/her life. In summary, a large variety of
terms referring to nonuse can be found in the literature (also see
Supplementary Table S7).
Categories of factors reported as related to (non-)use of
magnifying low vision aids
Personal category
Demographic factors. Personal characteristics such as gender, age,
and education, were studied by several authors in order to estab-
lish if they have the potential to influence and predict the (non-
)use of magnifying low vision aids. Although a consensus was not
always observed, the studies provided different insights.
Regarding gender, it was found that females were more likely to
use assistive technology after the provision and after one year fol-
lowing the provision [30]. However, in another study the authors
indicated that gender was not significantly related to the per-
ceived benefit of a magnifying low vision aid [20]. As far as age is
concerned, several studies did not reveal any significant relation
to low vision aid use [10,11,30,31], nor was age an indicator of
successful device use [20]. One study indicated that there was no
evidence for low vision aids to be less frequently used by older
patients [12]. In contrast, other studies highlighted that age was a
risk factor for not using a magnifying low vision aids; it appeared
that increasing age was a factor in decreasing compliance. For
instance, Demirkilinc et al. [28] stated that 73% of their patients
who were 65 years old or younger used their low vision aid. In
contrast, only 47% of their patients older than 65 years used their
devices. Similarly, Watson et al. [31] indicated that those under
the age of 74 reported the most success with their device use.
Other authors came to the same conclusion; however, they
revealed that age could not be used as a reliable predictor of
patient satisfaction or of eventual benefit [10]. Moreover, individu-
als with more education were more likely to use assistive technol-
ogy initially, and education was significantly linked to change in
the use of assistive technology over time, whereby those with
more education showed a tendency to reduce the number of
devices used over one year [30]. Other authors affirmed that
lower education was not a contributing factor of device abandon-
ment [29]. Finally, one study concluded that none of the demo-
graphic characteristics were significantly different between those
who had abandoned a device and those who had not [8].
Physical factors. Physical factors were defined as characteristics
such as: diagnosis, type of visual field deficit, duration of vision
loss, visual acuity, global change in vision and functional and
physiological issues.
The effect of diagnosis on the use of low vision aids had been
studied by several authors, with divergent conclusions. Some did
not detect a statistically significant difference in the usage rate
across diagnostic groups [11,28,31]. However, for other authors
etiology constituted a predictive factor related to device compli-
ance. For instance, McIlwaine et al. [10] concluded that patients
with non-macular disease tended to have lower compliance rates
than patients with macular disease; however, they highlighted
that etiology could not be used as a reliable predictor of patient
satisfaction or of eventual benefit. It appeared that the type of vis-
ual field deficit was considered as a consistent predictive factor
related to low vision aid compliance, whereby several authors
observed that patients who had a documented loss of non-central
visual field were significantly more likely to have abandoned their
magnifying low vision aid [8,26,33]. One study reported that dur-
ation of vision loss on low vision aid compliance was positively
related with low vision aid use at the delivery time and after one
year, with an even stronger relation after a one-year period than
initially [30]. Visual acuity was an important factor, and its link to
device use has been studied extensively; however, divergent con-
clusions emerged from this scoping review. Some authors indi-
cated that the patients’visual acuities were related to the
compliance rate; for example, decreasing visual acuity might
decrease compliance without visual acuity being used as a reli-
able predictor of patient satisfaction or of eventual benefit [10].
Interestingly, for these authors, visual acuity could not be used as
a reliable predictor of patient satisfaction or of eventual benefit.
In contrast, for others, visual acuity was not statistically related to
continued use [11,28].
Global change in vision appeared as a factor related to per-
ceived benefit of low vision aids use and motivation to use these
aids [24] and was largely considered as a predicting factor of
magnifying low vision aid usage. When vision was worse
(decrease in visual acuity or general loss in vision), it appeared
that usage rate was lower [8,11,25]. Two studies highlighted that
when vision was much worse, aid use also decreased. However,
the authors indicated that device use was improved when vision
was improved or declined, and when it remained stable, device
usage remained constant [20,26].
Finally, among the other factors influencing success in magnifying
low vision aid usage, functional and physiological issues such as
degree of residual vision [25], fixation and focusing problems [24],
and general age-related health changes or poor health were
reported as relevant [25]. Interestingly, from a functional perspective,
one study highlighted that when comparing subjects with a different
level of disability (evaluated by a visual function questionnaire) at
the beginning of device acquisition, those with a lower level of dis-
ability maintained a high level of use, suggesting that the level of
disability did not appear to be predictive of (non)-use [18].
Psycho-social factors. Psycho-social factors make reference to vari-
ous aspects in which magnifying low vision aids might impact on
4 M-C. LORENZINI ET AL.
the individual’s internal state, they refer to: perceived effective-
ness, adaptability, self-esteem, confidence, and motivation.
For a device to be used, it must be perceived as effective to
the one who uses it and provide some level of benefit. In this sec-
tion, benefit makes reference to what extent the device meets the
needs of its user, and concerns both occupational factors, refer-
ring to activities of daily living, and functional factors, making ref-
erence to more general near or distance tasks. Benefits of low
vision aids might be seen as a substantial solution to a variety of
needs, including reading, writing, and money management [35].
Moreover, the number of tasks that a patient was able to accom-
plish with a device was associated with perceived success [19,20].
Feeling more competent and productive was a major factor influ-
encing device usage [32]. Moreover, some studies point out that
certain devices could encourage their use for new additional tasks
beyond those initially anticipated, which could be considered as a
signifier of success [35]. Indeed, it was estimated that 42% of the
devices were used for additional tasks, with an average of two
new tasks per device [11]. Similarly, Copolillo et al. [35] were inter-
ested in characteristics leading to successful low vision aid use
decision-making, and highlighted the importance of experiencing
positive appraisals of devices and discovering unexpected advan-
tages. Intuitively, when the user failed to effectively realize a task
with a device, the chances of abandonment increased [8]. It is
important to highlight that, even if participants had abandoned
their devices because they did not completely meet their needs,
they recognized how much the device served them [26].
Adaptability is defined here as the ability to adjust to one’s vis-
ual disability, to develop new strategies, to involve coping mecha-
nisms to face the challenges of visual disability. In this scoping
review, adaptability appeared to substantially affect magnifying
low vision aids use. For example, Copolillo et al. [35,p.310] made
reference to “adjustment to low vision disability”, involving differ-
ent components, such as experiencing emotional reactions to hav-
ing to abandon desired activities, making psychological and
logistic adjustments, and maintaining independence. Similarly,
other authors investigated factors influencing success or usage
failure and concluded that psychological and emotional adjust-
ment to life with a visual impairment were considered success
indicators [25,26]. Interestingly, one study revealed that assistive
technology users with visual impairments showed a statistically
higher level of adaptability versus those with another sensory or
with motor impairments [32]. In the majority of the cases
reported, developing new strategies and skills influenced usage
success; however, this was not always the case. For example,
Bachofer [26] indicated that some users developed other strat-
egies for the period when visual access was problematic, they felt
that their coping skills were strong enough that the low vision
aids use was not deemed necessary.
Self-esteem and self-confidence were considered by some
authors as key to success in the process of magnifying low vision
aid use [32]. Moreover, confidence in assistive technology and
placing high personal value on optical devices had been reported
as a successful user’s characteristics [26].
Motivation emerged as one of the main psychological factors,
having received the most attention in the reviewed articles, and
was influenced by intrinsic need as well as the presence/absence
of depression. In this scoping review, studies that focused on
motivation, agreed in their reports about its substantial influence
on the use of optical low vision aids. Some authors indicated psy-
chological reasons for the non-acceptance or discontinuation of
an optical low vision aid, such as poor motivation and depression
[24,25]. Elsewhere, motivation was associated with success [32].
Moreover, for a user to use a device, it was necessary not only
that s/he had identified its utility but also the need to use it.
These two components were considered as fundamen-
tal [24,26,28].
Other personal factors. Use of several low vision aids: Other
material resources closely related to device nonuse or discontinu-
ation relate to the use of another or other device(s) to complete
the task [8,11,31]. The number of low vision aids owned was not
related to successful or continued device use [20].
Combination of personal factors: A specific combination of per-
sonal factors previously cited could represent a predictor of the
participants’confidence about device use. According to Bachofer
[26], device users were statistically more confident about magnify-
ing low vision aid use if they were male, had better central vision,
and had used optical devices for a longer period of time.
However, no direct comparison between these factors and the rate
of use was made. Although a classification was used to make dis-
tinctions among the main categories related to the use of low
vision aids, certain complex factors are influenced by overlap
among categories as well as their interactions. This overlap is dem-
onstrated in more detail in Figure 2. For example, satisfaction
towards device use may be interpreted both as within the personal
and the device categories. Satisfaction is reported here globally,
without any distinction of specific components (i.e., performance,
ease of use, service provided, counseling). Few of the selected stud-
ies revealed information about the users’global satisfaction with
their devices. Using the Quebec User Evaluation with Assistive
Technology questionnaire to assess user’s satisfaction [36], Burton
et al. [32], stated that participants generally reported medium to
high satisfaction with their assistive technology. Also, the number
of tasks that a user was able to accomplish and the frequency of
use had been associated with perceived success but not duration
of use [20]. Interestingly, despite using a device, user may not
necessary be satisfied by using it. Indeed, among patients who
used their low vision aid, only 30% were satisfied [28]. Along the
same lines, another study exhibited a significant reduction in
patient satisfaction after 18 months, compared to the initial 3
months. Yet, disability was reduced from the low vision aid acquisi-
tion, the use of devices remained high, and there was no substan-
tial change in device use for the same time period [18].
Device category
Factors in this category refer to objective and subjective compo-
nents of the device. Objective aspects make reference to intrinsic
parameters of the device such as: dimensions, weights, ergonom-
ics, quality, effectiveness, and maintenance. Subjective aspects
define extrinsic parameters involving the habits or the judgment
of the user such as: frequency and duration of use, design/
appearance, or ease of use.
Objective device-related factors. Types, dimensions, weight,
design/ergonomics, quality of the device, technical performance
and price may be considered as facilitators or barriers. Two stud-
ies indicated that low vision aid type was relevant because dis-
tance low vision aids were characterized by a very high rate of
rejection as compared to near low vision aids [24,33]. Dimension
and weight were considered as challenges to successful device
usage. Indeed, limits of low vision aids use were reported for
devices characterized as too big, heavy, or as taking too much
space [10,35]. Another reason for discontinuing use were the
ergonomics [11]. Rinnert et al. [27] indicated that, of approxi-
mately one fifth of nonused low vision aids, one of the
MAGNIFYING LOW VISION AIDS 5
responsible reasons was impractical handling of the device.
Another reason related to the ergonomics was cited by Chan
et al. [24] and concerned five of 30 participants who decided not
to use a microscopic system because of the uncomfortable short
working distance between the reading material and the eye. The
quality of the device was also a predictor of the (non-)use,
whereby 17% of participants abandoned their device because of
a defective lens that interfered with use [8]. Technical perform-
ance was mentioned in some studies and corresponded to the
functionality that a device may have, depending on the nature of
its technical components. One of the main reasons reported by
users who had abandoned their device was that the magnifying
power was too low [11]. The cost of the device and its mainten-
ance were important factors mentioned as potentially impacting
the usage but they were not extensively studied [29].
Maintenance is not only related to the device but also to the
intervention and may be analyzed as a more complex combin-
ation of factors belonging to two categories (i.e., device and inter-
vention categories).
Subjective device-related factors. The way in which the device is
used is intimately related to the user’s lifestyle. It appeared that
the frequency of low vision aid use was a good indicator of its
perceived benefit [28]. However, for other authors the duration
and frequency of use did not represent a success predictor [20].
Reasons for discontinuing usage also related to dislike of the
design and appearance [11]. Magnifying low vision aids character-
ized as awkward [26,35] or with a cumbersome appearance [33]
were often abandoned. The ease to use a device is an intuitive
indicator. Demirkilinc et al. [28] stated that 29% of the patients
who obtained a low vision aid, but never used it had done so
because the devices were not practical, a finding replicated by
Bachofer [26]. Additionally, magnifying low vision aids continued
to be abandoned due to time-consuming manipulation [33]. In
the context of children with low vision, device features that were
not adapted to their age, represented a barrier [19]. The place
where users keep their device was considered as an indicator of
successful use (i.e., reachable versus inaccessible) [20].
Maintenance, as well as professional or follow-up services were
Other material
resources
Combinaon of
personal factors
Demographic
Physical factors
Subjecve
device-related factors
Psycho-social
factors
Immediate
social circle
Customer services
Follow-up
services
Physical factors
Societal level
Origin of the
provision
Training
Instrucon
Clinician atude
Magnifying
Low Vision
Use
Objecve
device-related factors
Sasfacon
(age, gender, education, living situation)
(diagnosis, visual eld,
visual acuity, change in vision, duration of vision loss, residual
vision, age related changes, functional issues)
(infrastructure, installation,
equipement)
(caregivers, familly, friends,
helpers at home)
(functional competence-ecacy,
adaptability, motivation,
emotional-self-estime condence,)
(stigmatization, encouragement)
(ease of use, appearance, design,
frequency/duration of use)
(dimensions, eectiveness,
weight, quality, ergonomics)
(duration, frequency)
(awareness/knowledge of low vision rehabilitation
services, relationship with patient)
(professional services,
maintenance)
(basic features)
Environment
Intervenon
Device
Personal
Figure 2. Classification of categories influencing the use of magnifying low vision aids. Figure 2 displays the factors involved in the use of low vision aids according
to the selected articles of this scoping review. The most frequently mentioned contributing factors are indicated in bold and small characters.
6 M-C. LORENZINI ET AL.
classified in a combination of the device and the intervention cate-
gories. The fact that a device had been lost or broken and had
not been replaced was one of the reasons for not using magnify-
ing low vision aids [26].
Social acceptance and fear of stigmatization can be related to
the psycho-social impact of the device on the user and is another
example of overlap. They might be considered part of device
(subjective factors), personal (psychological), and environment
(society) categories. Little information was found within the
reviewed studies. In one study, magnifying aid users were charac-
terized by having a high social acceptance of their devices [26].
Surprisingly, Copolillo et al. [35] reported that the literature did
not document fear of stigmatization as a major concern for older
adults; however, this fear constituted one of the reasons for not
using devices by younger adults [26].
Environmental category
Environmental factors refer to the immediate personal social circle
(e.g., caregivers, family and friends), the larger-scale social environ-
ment (e.g., at the societal level), as well as the physical environ-
ment (e.g., urban or home architecture, outside and interior
infrastructures). The social circle is probably the most frequently
solicited support environment by the visually impaired person,
and includes individuals who are most familiar with the person’s
needs. Resource exchange refers to a well-established, informal
network of families, friends and people with low vision [35]. It has
been demonstrated that having a supporting individual in the
home was significantly related to use of the low vision aids
[11,31], where the probability was 1.9 times higher of continued
device use [11]. The majority of study participants across publica-
tions referred to the family as a support system; however, some
also acknowledged the potential negative effect on autonomy by
relying on family instead of independent action initiated by the
person with a visual impairment. For example some individuals
were pressured into getting a device by their family without really
wanting it [8].
The extended social environment can also potentially impact
on how a person will use a technological aid. Its effect can be a
facilitator as reported by Burton et al. [32]. When asking the ques-
tion, "What have been the biggest keys to your success with
assistive technologies?" one user commented, "It’s about taking
recommendations from other very important folks" [32,p.104] . In
parallel, the impact of society can induce the opposite effect; for
example, Bachofer [26] reported a form of stigmatization induced
by student’s mockery, causing abandonment of the low vision
aids. Interestingly, a recent randomized controlled trial exhibited
no negative peer comments for children experimenting with
iPads as a mainstream device at school [19].
Physical barriers to device training represent another cause of
potential nonuse. Infrastructure, such as limited access to trans-
portation, appeared to limit the ability to receive training with a
device [29]. Lack of supplementary materials to facilitate device
use, such as a reading desk, was also a limiting factor, highlight-
ing the importance of equipment and appropriate installation for
the optimal devices use home [8]. In some cases, although light-
ing needs were assessed in the clinic, they could also be problem-
atic if the user was unable to maintain and control the optimal
illumination level at home [31]. These non-optimal lighting condi-
tions should all the more to be taken into consideration, as a fifth
of low vision aid nonuse was caused by unsatisfactory illumin-
ation [27]. In addition, with the use of mainstream devices, a con-
nected environment becomes indispensable. For example, in the
context of the use of an iPad by visually impaired children in
school, a lack of access to the Internet had been reported as a
major barrier [19].
Intervention category
For a device to be disseminated to the user, practitioners/profes-
sionals must be aware of the existence of the device, and be able
to identify the needs of their patients in order to direct them
towards the most beneficial magnifying low vision aid. It seems
obvious that appropriate devices assured continuous use [35]. Yet,
Copolillo et al. [35] observed that a certain number of professio-
nals lacked awareness of optical low vision aids as alternative
solution and did not discuss low vision devices with their patients
nor oriented them towards low vision rehabilitation services. It
appeared that maintaining positive interactions between the
patient/client and low vision health care professionals were essen-
tial in the process of acquiring and incorporating low vision devi-
ces. Negative health care experiences, unmet device needs, poor
knowledge of devices, and delays in obtaining an appointment
were considered as barriers to magnifying devices use [35].
When an individual starts to use an assistive technology, s/he
should undergo the correct provision process, training in its use
and installation in the specific environment or context. Proper
instructions about the use and maintenance of the device by the
clinician or any provider appeared as essential to enhance the use
of a device [23]. Indeed, one fifth of nonused low vision aids were
abandoned, in part, because the prescribing practitioner failed to
provide instructions [27]. Innovative therapeutic education strat-
egies are increasingly used in visual rehabilitation. For example,
the impact of a video program, explaining ocular disease and
treatment solutions and optical devices, on knowledge and will-
ingness to use the devices have been explored and the authors
concluded that the video program had a clinically small but statis-
tically significant impact on use [29].
After initial and basic instructions, training emerged as an
important component for magnifying low vision aid users. Indeed,
50% of users felt training was somewhat to extremely important
and was very critical of how care is provided and how monitoring
is ensured. [32]. According to McIlwaine et al. [10], 50% of
patients were not satisfied with the service they received, of
which 25% requested more training in the use of their device,
and about 50% wanted follow-up appointments. However, in
another study 75% of participants preferred to have access to a
setting where they could try out on their own different devices
and ask question, rather than a specific group or individual train-
ing session [32].
The duration and frequency of training seemed to be predic-
tors of a high level of compliance. Some authors suggested that a
higher degree of training could be related to successful low vision
aids use [31]. For example, a very high compliance rate was
observed in a population of low vision veterans, where most of
them received more than 20 hrs of training and more than 20 hrs
of practice in the use of their devices at the clinic. Among these
veterans, 95% stated receiving enough training and practice [11].
In another study, the authors highlighted that health services pro-
viding intensive training in optical device use achieved a higher
level of compliance. These same authors concluded that a mean
to improve service may be operated by employing additional pro-
viders specifically trained to teach low vision patients how to
optimize the use of their devices [10]. Finally, frequency of use
was a better indicator of perceived benefit from low vision
rehabilitation [20]. Clinical training is the most commonly
reported intervention type, but for ecological reasons, some
authors highlighted the importance of transferring learning from
MAGNIFYING LOW VISION AIDS 7
the clinic to the home when attempting to incorporate optical
low vision aids into the daily routine [35]. Finally, neither the
number of visits to the clinic nor the place where the device was
provided constituted factors of success [20]. However, others
observed that, although some users may be disappointed by their
device, the use of magnifying low vision aids was more frequent
by those who had attended a low vision clinic [12], whereas bene-
fits from attending the clinic were reported by 89.5% of patients
and 81% of patients were regularly using low vision devices [20].
Discussion
The purpose of the present scoping review was to map the litera-
ture on factors related to magnifying low vision aids (non-)use,
building on an existing classification of assistive technology non-
use in general [13,14]. As expected, the previously established
four categories (personal,device-related,environmental and inter-
ventional) were well suited for the classification of the factors that
emerged from our review, whereby the most frequently reported
category consisted of factors related to the personal characteris-
tics of the devices users.
Expected and present findings
Personal category
Demographic factors have been identified in this review as con-
flictingly influencing low vision aid (non-)usage. The effects of
age, gender, and education were reported in the selected studies
in an inconsistent way. In parallel to some demographic factors
identified here as contradictorily influencing low vision aid (non-
)usage, the influence of age was also reported in the literature in
an inconsistent way. Advanced age of the users represented one
of the predictors for nonuse. For example, Zammitt et al. [37] had
identified that referral at an early age represented a factor likely
to positively affect device use. It appeared that elderly patients
were more likely to have general associated health problems and
limited dexterity skills, which impacted on low vision aid use.
However, in other studies, age had not been associated with
(non-)use of devices [38]. Leat et al. [39] did not find a relation-
ship between age and perceived benefit of low vision aids use as
a measure of success.
Regarding physical factors, the effects of diagnosis, visual acu-
ity, and visual fields deficit on the use of low vision aids had been
studied by several authors and divergent conclusions emerged.
One study looked at the effect of duration of vision loss on device
compliance and reported it to be positively related with low
vision aid use. Change in vision appeared as an important factor
related to device use, whereby, when vision was worse low vision
aid use was decreased. As reviewed here, it seems that a consen-
sus was not always observed regarding conclusions related to eti-
ology. Indeed, while some authors considered ocular diagnosis as
a predictor of use [40], others reported that etiology did not
affect the continued use of devices in patients with diabetic retin-
opathy, glaucoma, optic atrophy, myopia, and retinitis pigmen-
tosa, as well as in patients with macular degeneration [34].
Considering psycho-social factors, very little information was
obtained regarding the social acceptance of low vision aids, and
findings about stigmatization did not entirely converge. However,
psychological factors were explored in different ways through
functional competence-efficacy,adaptability, self-esteem, confidence,
and motivation, having been reported as predictors of use.
Motivation and adaptability are certainly the main psychological
factors, having received the most attention in the reviewed
articles and appearing as substantially affecting magnifying devi-
ces use. In line with these findings, literature exploring assistive
devices use in other disabilities highlights that the functional com-
petence or efficacy with the device is an important issue. If in gen-
eral an assistive technology fails to improve function, it will
probably be abandoned [41]. Regarding the psycho-social factors,
many reasons for abandonment of assistive technologies are
reported, but among the important reasons identified by the
users, appearance remains a major concern [42]. Negative terms
evoked by users, such as the fear to feel “dehumanized”or to
appear “freaky”qualified their discomfort. Several studies related
to low vision aid use in general and not necessarily related to
magnifying systems, highlighted the importance of the motiv-
ational and need factors. Series of focus groups, conducted by the
National Eye Institute (NEI) in the U.S. in 2001 [43], identified that
patient motivation was one of the barriers to follow through on
referral. Healthier psychological status and higher motivation at
the time of rehabilitation were associated with better outcomes
[44]. Along these lines, Overbury et al. [45] found that success
with low vision aids was positively associated with present need
for activities requiring vision. When the assistive technology was
well integrated into the users’own life, device users felt grateful,
and when they considered the device as a physical extension of
themselves, the acceptance was described as internal [46].
Surprisingly, 23% of the general low vision aids prescribed were
found useful at home [40]. Acceptance is compromised when a
person accepts the assistive technology only when there is a
need and when it is a means of carrying out activities of daily liv-
ing [47]. Psychological factors, such as adaptability, were also
highlighted by several authors; coping strategies influenced
acceptability of an assistive device, they referred either to per-
sonal adaptation, or active modification of the environment [48].
Device category
Design and appearance emerged as predictors of use, and devices
whose appearance was judged negatively by their owners were
mainly not used. Several studies converged in the conclusion that
ease of use is another major factor. Devices perceived as awkward
are likely to be abandoned [49]. In parallel to theses subjective
aspects identified in the present review, the difficulty in operating
the device and its maintenance were reported as major barriers
for assistive technology use in general [50]. Regarding the object-
ive aspects, dimension, weight and ergonomics emerged here as
challenges to successful low vision aid usage. In line with this
conclusion, assistive technologies that feel heavy or defective
were not being used [49]. In this scoping review, low vision aid
type mattered since distance devices were characterized by a very
high rate of rejection as compared to near devices. However, this
findings needs to be considered with a grain of salt, given that
only one study reported a non-usage rate for distance low vision
aids. Proportionally, low vision aids for near tasks were the most
prescribed because near vision activities, such as reading, are the
main reason for consultation in low vision rehabilitation. Patients
used more microscope than telescope systems because they had
a greater need for near vision tasks in their daily lives, and also
because telescope systems may present problems of focusing and
fixation at a certain level of magnification [24].
Environmental category
Regarding environmental factors and, more specifically, the users’
social circle, the majority of the selected studies referred to the
family as a support system. Having a helper at home was signifi-
cantly related to use of the low vision aids. Parallels in the
8 M-C. LORENZINI ET AL.
literature have been reported whereby parental involvement has
been shown to be a statistically significant predictor of device
use. For example, high school students having a visual impair-
ment with parents involved in several parent meetings or partici-
pating in training sessions were more likely to use assistive
devices in comparison to those whose parents were not involved
[51]. Similarly, Zammitt et al. [37] found that a lack of involvement
of the child’s teacher and parent negatively affected device use.
However, the influence of family did not seem to easily replicate
as Overbury et al. [45] found that success with low vision aids in
general was not positively associated with the degree of family
support. While this scoping review provides little insight about
social acceptance, previous reports indicate that stereotypes main-
tained in society and the media in general might negatively influ-
ence the use of assistive devices [52]. Various studies indicated
that fear of stigma and marginalization is implicated in the pro-
cess of deciding when and under what conditions to use low
vision aids[53,54]. Change in personal competencies suggested by
the use of an assistive technology may have the potential to trig-
ger negative social judgments and affect its acceptability [55].
Many of the studies selected here agree that the physical environ-
ment can represent barriers to device use. This scoping review
shows the importance of equipment and appropriate installation
for the optimal use of devices at home, and that a lack of
adapted materials/environment represents an important barrier.
Limiting physical access to training represents an important cause
of potential nonuse as well. Similarly, transportation to and from
device training was identified as a barrier [43]. Given that environ-
mental barriers can indirectly limit the acceptance of an assistive
technology, other authors insisted on the importance to assess
physical environmental barriers in the home and in the outdoor
environment [56].
Intervention category
Among intervention characteristics, professionals lacked aware-
ness of low vision rehabilitation services and types of available
low vision aids are commonly reported as barriers. Negative inter-
actions between the patient and healthcare professional represent
another barrier to use in the context of the provisioning and attri-
bution processes. Similarly, knowledge of and ability to communi-
cate about a patient’s visual impairment might have an impact on
positive response to using low vision aids [57]. It seems obvious
that for a patient to access low vision services or appropriate
devices, it is necessary to first be aware of their existence.
However, not only are many adults unaware that they are eligible
to receive low vision services, but they have limited knowledge
about the varieties and types of available low vision aids and
whether they may be of benefit. For example, individuals with
low vision have very limited awareness of the benefits of add-
itional lighting [58], while limited knowledge of both services and
devices substantially contributed to the delay or absence of
device acquisition [59]. Another barrier to referral was the length
of time to obtain an appointment [43]. Yet, delayed introduction
to devices negatively affected device use [37].
Proper basic instructions and training about the use and main-
tenance of a device by the clinician or any provider appeared as
essential to enhance the use of magnifying low vision aids.
Interestingly, duration and frequency of training seem to be pre-
dictors of a high level of compliance and most of the selected
studies agree that intensive programs increase device use.
Similarly, training has previously been identified as an important
aspect in the process of low vision aid use in the literature at
large (i.e., not necessary related to magnifying systems). For
example, in different studies involving patients with visual loss
due to complications of diabetes [60] or macular degeneration
[34], training was considered as essential, and insufficient training
negatively affected device use [37]. An increase in quality and
quantity of training in device use had been identified as a poten-
tial correlate of successful low vision aid use [35]. Interestingly, in
comparison with traditional low vision services, Shuttleworth et al.
[61] argued the importance of an integrated approach to low
vision rehabilitation with an emphasis on training. In view of the
importance of training, the characteristics of the population are
relevant. Indeed, older adults might experience difficulty transfer-
ring what they have learned in a clinic to their living environment
[62]. Finally, to maintain relevant training specifically addressing
the individual’s needs, regular follow-up was necessary, as failure
to provide timely reassessment negatively affected device use
[37]. While the present study did not find congruent conclusions
related to the place where the individuals practice with their device,
literature provides insights. In the context of young adults, school
placement represented a statistically significant predictor of
device use. For example, high school students with low vision
attending residential schools were 1.8 times more likely to use
assistive technologies than not attending [51].
Expected but absent findings
Interestingly, some anticipated factors such as quality of life, did
not emerge in this scoping review. Although different psycho-
social factors have been studied separately, they have not been
related to each other so as to reflect quality of life more gener-
ally. Yet, in the same way as if an assistive device fails to improve
function, or if quality of life is not improved or even declines, the
device probably be abandoned. For example, Day et al. [63,p. 34]
stated that “an assistive device should promote good quality of
life for the user to the extent to which it makes the user feel
competent, confident and inclined (or motivated) to exploit life’s
possibilities”. Taking into account quality of life, the Psychosocial
Impact of Assistive Devices Scale (PIADS) [41] was developed spe-
cifically to assess this dimension of assistive technology use. It
reflects the quality of life with three distinct subscales: compe-
tence, adaptability and self-esteem, and is a reliable and valid tool
that appears to have significant power to predict abandonment
and retention.
In the present study, the focus is on optical and non-optical
magnifying systems. Most of the studies concerned near optical
low vision aids, such as handheld and stand magnifiers. In con-
trast, very little information has been gathered about magnifying
software. Yet, software has become more and more available with
the digital development, and its use is widespread among individ-
uals with visual impairment that are using computers. A prelimin-
ary search within online databases revealed articles about tablets
and smartphones as low vision aids [64]; however, these articles
were excluded from this scoping review because they were not
associated with nonuse but only focused on performance meas-
ure comparisons. Unexpectedly, taking the user opinion into
account during the low vision aid selection process did not
emerge as a factor. Yet, the literature defending the need to
include user input in the process of assistive device provision is
abundant [41,63,65].
Finally, the present scoping review focused on sophisticated
devices requiring a certain budget. One expected major potential
negative factor that did not appear in the selected studies was
the expense related to the devices; yet, a series of focus groups
[43] had identified the cost of visual aids as one of the major
MAGNIFYING LOW VISION AIDS 9
barriers to referral. More generally, cost has been identified as the
primary barrier to acquiring all assistive technology, including low
vision aids [5,66]. In line with these findings, devices outside of
low vision also faced this issue. We speculate that the regional
differences in third-party payer systems and insurance eligibilities
across countries are partially responsible for why the topic of
funding and device expenses is only discussed within the context
of cost-benefit analyses but not within studies on device
abandonment.
Theories on the prediction of compliance behavior
Parallels have been found between the mechanisms influencing
nonuse of assistive technology and those influencing non-adher-
ence with other medical interventions [67]. Adherence to health-
care treatments or intervention is complex involving multiple
factors that interact and produce individual behaviors. Model-
linked medication adherence interventions, such as the Theory of
Planned Behavior, the Health Belief Model and the Medication-
Taking Behavior Model [68–70] propose four influencing catego-
ries of factors related to the: person (e.g., self-efficacy, cognitive
impairment, culture and ethnicity, stress, depression, comorbid
conditions); health system (e.g., access to medication, care deliv-
ery approach); treatment (e.g., cost, regimen complexity, treat-
ment duration) and environment (interpersonal influences, or
information from friends, relatives). Although these categories are
named differently, there is large overlap in their content when
compared to those identified here for assistive technologies and
low vision aids [13,14].
Currently, more and more medical research is based on psy-
chological theories in order to study and predict the adherence
to and compliance with a specific treatment. The extent of theory
use and intervention effectiveness in terms of adherence and clin-
ical outcomes varied across studies. Interestingly, Livi et al. [71]
used a health behavior theory to predict noncompliance with
daily disposable contact lenses replacement. Using the Theory of
Planned Behavior model [72], they showed that user’s perceived
behavioral control and its subjective norms are two significant
predictors of compliance behavior. Regarding technology accept-
ance, The Technology Acceptance Model [73] and the Unified
Theory of Acceptance and Use of Technology [74] are the models
often employed to explain (non-)usage based on specific predic-
tors. These two models are relevant but do not take into account
biophysical, psychological, and contextual factors [75]. In this con-
text, the biopsychosocial model of the International Classification
of Functioning, Disability and Health [76] had been identified as a
more comprehensive predictive model to determine the best
match between person and technology [77]. Despite the increas-
ing use of theories, more research testing theory-based interven-
tions is necessary to add to the body of evidence in this field
[78]. Indeed, only 18% of medical adherence interventions identi-
fied reported using a theory or conceptual framework for devel-
oping interventions [79]. In comparison, only 15% of the studies
included in the present scoping review used a conceptual frame-
work. Among them, the theories included were mainly borrowed
from the field of health psychology, but were not directly related
to prediction of compliance behavior or potential to adopt a par-
ticular technology. Like in many medical interventions, it would
be relevant and advisable to use theories, such as Health
Psychology Theories or those related to assistive technology mod-
els to explain the mechanisms underlying the use of low
vision aids.
Clinical Implications
The results suggest that clinicians should establish positive part-
nerships with patients for them to better be able to understand
the necessity and expected effectiveness of the low vision
rehabilitation services and devices as prescribed. It appears that
acceptability of assistive technology is highly related to its charac-
teristics and emphasizes the need for developing/enhancing col-
laborations between clinicians, researchers, engineers and
industry in order to pool their expertise and efforts towards emer-
gence of effective and appropriate assistive technologies accepted
by the target population. These findings also suggest that clini-
cians should involve patient’s relatives more in the rehabilitation
process. Health policy and healthcare providers should further
support the deployment of evaluation and training in the
patient’s home, providing individualized services, overcoming
physical distance as a barrier, and promoting innovative interven-
tion, such as telerehabilitation.
Limitations and next directions
Several challenges in this scoping review were associated with
the heterogeneity in terms of populations, low vision aids, adher-
ence definition, adherence measurement, application of relevant
theory in terms of independent variable selection, study duration,
and presentation of outcomes. Regarding the populations, the
reviewed studies mainly focused on older adults with a diagnosis
of macular degeneration. Thus, it seems difficult to generalize to
the entire low vision population. In terms of type of magnifying
low vision aids, studies related to tablets and smartphones were
mostly excluded because all except one did not included meas-
ures of nonuse or related factors. More information on the rea-
sons for abandoning these technologies and comparisons with
conventional low vision systems would provide a more complete
view, especially as these current technologies are increasingly
used as magnifying visual aids by the visually impaired population
[64,80]. Given their multi-functionality, it will be interesting to
observe how nonuse will eventually be defined for these devices,
as they may be used for some activities in an adapted format
(e.g., enhanced contrast) and for other functionalities without
adaptations (e.g., music). Moreover, it was difficult to isolate mag-
nifying devices during the review because some studies included
magnifying low vision aids exclusively while others did not. In
these cases, the specific information extracted on magnifying low
vision aids was compromised. Several challenges were associated
with the design of the studies. In the majority, self-report was the
main measure of low vision aid use. However, indirect measures
can involve some degree of assumption that a participant has
used the device, leading to a potential overestimation of utiliza-
tion, thereby reflecting response bias. Further, few of the studies
were longitudinal with follow-up assessments of usage rate, and
very little information was available about changes in magnifying
low vision aid (non-)use over time. Despite the limitations, we
were able to identify and summarize a large number of predic-
tors. This scoping review repesents the first step, in the context of
exploring factors related to discontinuation of head-mounted dis-
plays, a new class of magnifying low vision aid, used both at near
and distance, for which we do not yet have insights about which
factors may be related to their nonuse. Both a cross-sectional
study and a prospective trial are ongoing to determine whether
similar variables are involved.
10 M-C. LORENZINI ET AL.
Conclusion
When studying the factors that affect the nonuse of low vision
aids, through an existing classification in four categories, it was
possible to replicate the same classification of personal, device-
related, environment and intervention categories to the specific
context of magnifying low vision aids. Although a categorical clas-
sification was used, there was a dynamic interconnection among
the four categories influencing the use of such devices. Certain
complex factors are influenced by overlap and interactions among
categories. We hope that our work will assist clinicians in their
efforts to identify patients that are unlikely to utilize their low
vision aids, and overcome their barriers to device acceptance. We
aim to provide evidence for optimal rehabilitation service provi-
sion to the low vision population designed to reduce device non-
use and to improve the patients’quality of life. The fact that
magnifying low vision aids and medical interventions in general
share the same categories influencing patients’behavior suggests
that strategies applied to enhance adherence of a treatment
might be useful to reduce nonuse of low vision aids. More com-
plete descriptions of interventions and the linkages between spe-
cific intervention components within a theory framework are the
next logical steps.
Disclosure statement
No potential conflict of interest was reported by the authors. This
study follows the principles of the Declaration of Helsinki.
.
Funding
The work was supported by Mitacs Accelerate Fellowship
IT08595 Grant
ORCID
Marie-C
eline Lorenzini http://orcid.org/0000-0001-5019-5350
Walter Wittich http://orcid.org/0000-0003-2184-6139
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