1. Clinical and Epidemiologic Research
Binocular Vision and Eye Movement Disorders in Older
Susan J. Leat,1
Lisa Li-Li Chan,1
Patricia K. Hrynchak,1
Carolyn M. Machan,1
and Elizabeth L. Irving1
School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
University of Waterloo, Waterloo, Ontario, Canada
Correspondence: Susan J. Leat,
School of Optometry and Vision
Science, University of Waterloo,
Waterloo, ON, Canada, N2L 3G1;
Submitted: December 29, 2012
Accepted: May 2, 2013
Citation: Leat SJ, Chan LL-L, Maharaj P-
D, et al. Binocular vision and eye
movement disorders in older adults.
Invest Ophthalmol Vis Sci.
PURPOSE. To determine the prevalence of binocular vision (BV) and eye movement disorders in
a clinic population of older adults.
METHODS. Retrospective clinic data were abstracted from ﬁles of 500 older patients seen at the
University of Waterloo Optometry Clinic over a 1-year period. Stratiﬁed sampling gave equal
numbers of patients in the 60 to 69, 70 to 79, and 80þ age groups. Data included age, general
and ocular history and symptoms, use of antidepressants, a habit of smoking, refraction, visual
acuity, BV and eye movement status for the most recent full oculo-visual assessment, and an
assessment 10 years prior. The prevalence of any BV or eye movement abnormal test (AT)
result, deﬁned as a test result outside the normal range, was determined. This included
strabismus (any) or phoria; incomitancy; poor pursuits; and remote near point of convergence
(NPC). The prevalence of signiﬁcant BV disorders (diagnostic entities, i.e., a clinical condition
that may need treatment and may have functional implications) was also determined.
RESULTS. The prevalence of any BV or eye movement AT was 41%, 44%, and 51% in the 60 to
69, 70 to 79, and 80þ age groups, respectively. These ﬁgures were lower for 10 years earlier:
31%, 36%, and 40% for ages 50 to 59, 60 to 69, and 70þ, respectively. The prevalence of any
BV or eye movement disorder was 27%, 30%, and 38% for the three age groups and 17%, 19%,
and 24% for 10 years prior. Age and use of antidepressants most commonly predicted BV or
eye movement AT or disorder.
CONCLUSIONS. BV disorders are common among older adults.
Keywords: aging, heterophoria, binocular vision disorders, eye movement disorders
There has been little attention paid to age-related changes in
binocularity or to the prevalence of binocular vision (BV)
disorders in older adults.1 The deﬁnition of what is included as
a BV disorder differs between studies, making them hard to
compare. Despite this, it appears that the overall prevalence of
BV disorders in prepresbyopic clinic populations is quite high,
ranging from 10%2
when only near esophoria or convergence
insufﬁciency were included, to 21.8%3
when any one of the
following conditions were included: convergence insufﬁciency,
basic eso- or exophoria, divergence excess, divergence
insufﬁciency, convergence excess, or reduced fusional ver-
gence ranges. Porcar and Martinez-Palomera4
found a total of
15.3% who exhibited either convergence insufﬁciency, conver-
gence excess, basic eso- or exophoria, or fusional vergence
dysfunction in a population of university students. These
studies excluded people with strabismus and the ﬁgures quoted
here exclude accommodative disorders. The prevalence of
strabismus has been found to be between 2.7% and 5.5% in
and is similar in the adult population.12–14
Therefore, this percentage should be added to the prevalence
of nonstrabismic BV disorders quoted above. There are, as far as
we are aware, no studies of the overall prevalence of BV
disorders speciﬁc to older adults.
There are, however, a few studies regarding speciﬁc
binocular changes in older adults. Yekta et al.15 found increased
near exophoria in adults aged up to 65 years and Palomo
´Alvarez et al.1
found no change in distance phoria in adults aged
up to 70 years. Pickwell16
reported an increase in prevalence of
high near associated exophoria between the ages of 40 to 59
and 60þ years. There have been reports of decreased prism
adaptation with age17,18 and Palomo ´Alvarez et al.1 showed
signiﬁcant decreases in positive and negative distance fusional
recovery points with increasing age. Older adult patients may
be more prone to a breakdown of BV, which could result in
poorer stereopsis, asthenopic symptoms, and possibly diplopia.
There are several reports of decreased stereopsis with age, with
especially large changes for some individuals aged over 60
has shown that stereoacuity
deteriorates with age more than high contrast visual acuity,
becoming 103 poorer in adults aged 90 to 95 years compared
with those aged 60 years. Deﬁcits in stereoacuity may be due to
sensory losses (monocular or binocular decreases of visual
acuity [VA]), but may also be caused by a breakdown of BV due
to changes in heterophoria or the onset of strabismus. Of
patients aged over 60 years receiving strabismus surgery, the
majority had strabismus secondary to disease processes
(neuroparalytic, mechanical restriction, or as a result of sensory
and 26% of the total had a vertical component.
Mechanical restriction included strabismus secondary to
thyroid disease, retinal detachment surgery, orbital ﬂoor
fracture, and multiple surgical procedures on the sinuses. The
most common reasons for strabismus surgery were diplopia
Copyright 2013 The Association for Research in Vision and Ophthalmology, Inc.
www.iovs.org j ISSN: 1552-5783 3798
2. and asthenopia. Magramm and Schlossman22
on patients having treatment, that the pattern of strabismus is
different in older adults compared with younger patients.
There are frequent reports that poor stereopsis is one of the
visual risk factors associated with falls and hip fractures in
older adults.23–28 Other aspects of vision that are associated
with the frequency of falls are poor visual acuity, reduced
contrast sensitivity, and visual ﬁeld loss (see Lord et al. for a
). Not all studies, however, have found a signiﬁcant
association between falls and these measures of visual
Reduced stereopsis has also been shown to be
associated with postural instability (increased sway on a foam
surface that disrupts proprioreception).31
good stereoacuity may help to reduce the incidence of falls and
improve general visual function and quality of life for older
people. Good BV is a prerequisite for maintaining good
Our hypothesis is that there are changes in binocular
function with advancing age. Our goals are to determine the
prevalence of BV and eye movement disorders in an older
clinic population and compare it with the prevalence in the
same population 10 years earlier. We also investigated factors
that may be associated with poorer BV and eye movement
This is a retrospective study of clinical information from the
ﬁles of 500 patients, aged 60 years and older, who were seen
for a full eye examination in the Primary Care Clinic at the
School of Optometry and Vision Science, University of
Waterloo, between January 22, 2008, and June 29, 2009. The
ﬁles of patients who had attended the clinic for at least 9 years
were randomly selected based on their clinic ﬁle number. Data
were retrieved from the most recent full oculo-visual assess-
ment, and an assessment 9 to 11 years prior, and entered into
the database. Files were selected until there was a stratiﬁed
sample with respect to age for the most recent eye
examination. This allowed an equal number of patients aged
60 to 69, 70 to 79, and 80þ years to be included for analysis.
Patients in their 80s and 90s were grouped together due to the
relatively low proportion of clinic patients aged 90þ years.
Additionally, the study did include three patients aged 59 years
(59, 59.6, and 59.9 years).
The data extracted included the patient’s sex and age; entering
symptoms (with a separate note taken of the presence of
diplopia); existing ocular and systemic diagnoses; a habit of
smoking; use of antidepressants (as it was thought that they
might have an effect on BV34,35
); the presence of any
strabismus; presence and amount of vertical and horizontal
distance and near phoria as measured by the alternating cover
test, and by Maddox rod, if undertaken; near point of
convergence (NPC); ocular motility; pursuits; incomitancy
(based on either Maddox rod or the alternating cover test
performed in the different positions of gaze or observations
during broad H motility testing); and best corrected visual
acuity. In the situation when there was a discrepancy between
the cover test and the Maddox rod results, the Maddox rod
result was used. Data from the following tests were also
included for those patients for whom they were measured;
fusion with the Worth 4 Dot, stereopsis, and fusional reserves.
The patient ﬁle has prompted data entry boxes for all these
tests. The testing procedures for the individual tests are taught
and undertaken according to descriptions in Hrynchak et al.36
The standard tests used in the clinic are listed in Table 1. As it is
a teaching clinic, occasionally there were cases in which the
supervising optometrist adjusted a student’s assessment. In
such situations, the corrected values provided by the
optometrist were used in the database. The case history
section of the patient ﬁle has checklist prompts for symptoms
such as diplopia, previous eye surgery or injury, current
smoking, medications, medical care, and last medical exami-
nation. The same research assistant, who acted as transcriber,
entered the data for both clinic visits. She was not masked
regarding the results of the previous visit, but did not compare
back or conﬁrm data between visits. Any queries were dealt
with by one of two optometrists who were investigators in the
This study was approved by the University of Waterloo’s
Ofﬁce of Research Ethics and followed the tenets of the
Declaration of Helsinki. Patients at the University of Waterloo
Optometry Clinic were made aware that data may be used from
their ﬁles for research purposes and that it would be
anonymous and kept conﬁdential. Patients could opt out of
this implied consent agreement.
Deﬁnitions of Terms
Several criteria were adopted in order to assess binocular
function. A single test result outside of the normal range was
deﬁned as an abnormal test (AT). The criteria used to deﬁne
ATs are listed in Table 1. The total percentage of people who
had one or more ATs of BV or eye movements was determined
(prevalence of ATs). The prevalence of each individual type of
AT was also calculated, with the exception of poor stereopsis
and abnormal Worth-4-Dot responses. The prevalence was not
calculated for stereopsis and Worth-4-Dot as these tests were
not undertaken routinely on patients. Since a single AT may not
result in the experience of a disability (i.e., a difﬁculty in
interacting with the environment37), we also deﬁned BV
disorders in the following way: a clinical condition that may
need treatment and may have functional implications (see
Table 1 for deﬁnitions of speciﬁc disorders). The percentage of
people who had one or more of these BV or eye movement
disorders was determined.
A comorbidity score was determined by counting the
number of comorbidities that were reported by the patient and
listed in the case history section of the ﬁle for that patient
encounter using the categories shown in Table 2. If a patient
reported more than one condition in a category (e.g., more
than one type of cancer), it was counted only once. This is an
approach that has been shown to give a good estimate of the
severity of comorbidity.38,39
Similarly, a score for the number of
already diagnosed ocular health conditions was determined
from the case history and the categories used for this are also
shown in Table 2. VAs were measured using Snellen notation
and converted into log of the minimum angle of resolution
(logMAR). Participants were separated according to whether
they had a visual acuity impairment (deﬁned as a VA worse
or logMAR 0.1 in the better eye) or low vision
(deﬁned as a VA worse than 6/1240,41
or logMAR 0.3 in the
better eye). VA was also considered for analysis in terms of the
logMAR VA for the right eye, left eye, the eye with poorer VA,
and the eye with better VA.
To consider the change in prevalence longitudinally, the 95%
conﬁdence intervals of the prevalence were calculated by the
Wald method and were considered signiﬁcantly different if the
conﬁdence intervals for each percentage did not overlap.
Cross-sectional association with age was considered with
BV and Eye Movement Disorders in Older Adults IOVS j May 2013 j Vol. 54 j No. 5 j 3799
3. univariate logistic regression. The prevalence of the following
independent variables were ﬁrst considered in a logistic
univariate analysis: age, sex, better and worse eye corrected
VA, presence of visual impairment, presence of low vision,
comorbidity score, ocular disease score, smoking, and use of
antidepressants. All univariate and multivariate analyses were
undertaken on the data collected in the same time period (i.e.,
not between the current and past datasets). The dependent
variables were the presence of either BV or eye movement AT,
disorder in the current data or 10 years prior. For each of these
dependent variables, a multivariate analysis was undertaken
using forward stepwise logistic regression, with alpha to enter
equaling 0.05 and alpha to remove equaling 0.15. The
independent variables that were included were those that
reached signiﬁcance (P < 0.05) or were moderately close to
signiﬁcance (P < 0.15) in the univariate analysis. Univariate
analysis was also used to determine any association with age
for each of the individual past and current ATs and disorders
(e.g., presence of strabismus or large distance exophoria). Data
were analyzed in a spreadsheet application (Microsoft Excel;
Microsoft Corp., Redmond, WA) for the descriptive statistics
and a statistics software package (Systat; Systat Software, Inc.,
Chicago, IL) for the regressions. For signiﬁcance, a value of P <
0.05 was used.
The total percentage of females was 56.8%. Figures 1A to 1I
show plots of the prevalence of the individual BV and eye
movement ATs and Figure 2 shows the prevalence of disorders
that were classiﬁed differently than ATs (decompensated
distance and near exophoria). Figure 3 and Table 3 show the
ﬁnal prevalence of any AT or disorder according to age for the
current and past visits. When equivalent age groups were
compared between the past and present data, no signiﬁcant
TABLE 2. Conditions Counted Toward the Comorbidity Score and the Ocular Disease Score
Comorbidities Counted for the Comorbidity Score Ocular Diseases Counted Toward the Ocular Disease Score
Heart disease and cardiovascular disorders Diabetic retinopathy or macular edema
Cancer (not including skin cancer) Cataract or other media opacity
Respiratory disorders Age-related maculopathy
Depression Previous retinal detachment
Thyroid disorders Epiretinal membrane
Cerebrovascular disorders (stroke) Retinal vein or artery (or branch) occlusion
Arthritis (osteo and rheumatoid) Other retinal conditions (e.g., retinoschisis, macular hole)
Other (e.g., dementia, seizures, Parkinson’s disease)
TABLE 1. Criteria for AT Results and Disorders
Criteria for AT Result Criteria for Disorder
Strabismus (unilateral cover test) Any Any
Distance or near vertical phoria (alternating
cover test using prism bars or MR with
room lights dimmed using a variable
>2 pd by CT or >1 pd by MR in the
As for AT
Distance exophoria (as for vertical phoria) >4 pd exophoria (by CT or MR) in the
As for AT PLUS abnormal þve fusional
reserves or symptoms of diplopia or
suppression (i.e., a distance phoria with
evidence of decompensation)
Near exophoria (alternating cover test using
>8 pd exophoria (by CT or MR)52,53 As for AT PLUS NPC >10 cm or symptoms
of diplopia or decreased stereopsis or
suppression (i.e., a near phoria with
evidence of decompensation)
Esophoria (alternating cover test using prism
NPC >10 cm See near exophoria
Incomitancy (as for vertical phoria but in the
horizontal and vertical positions of gaze,
motility testing undertaken with the
>1 pd vertical change or >5 pd horizontal
change between any direction of gaze (by
CT or MR) or any incomitancy in motility
As for AT
Anomaly of pursuits (observation with target
moved in horizontal and vertical
Suppression (performed in the dark, and if
abnormal results, repeated in the light)
Any suppression or unfused response on
See distance and near exophoria
Stereoacuity (Randot or Titmus circles at 40
>60 s See near exophoria
The standard test used in the clinic is brieﬂy described in parentheses. CT, cover test; MR, Maddox rod; W4D, Worth-4-Dot.
BV and Eye Movement Disorders in Older Adults IOVS j May 2013 j Vol. 54 j No. 5 j 3800
4. differences were found for either AT or disorder (Fisher exact
test, P > 0.05). Longitudinal analysis of the change of
prevalence across the 10-year period (comparing the same
patients currently and 10 years prior) was undertaken to
determine changes with age. The Fisher exact test showed that
there were no signiﬁcant differences in the ATs (except when
comparing the group aged 70–79 years with the group aged
80þ years), but there were signiﬁcantly more disorders with
increasing age (Table 3).
The results of the univariate logistic regression analysis are
shown in Table 4. Only those parameters that were signiﬁcant
or close to signiﬁcant at the P < 0.05 level, are shown. It can
be seen that the use of antidepressants and age were most
commonly associated with BV and eye movement AT or
disorder. AT in the past data was signiﬁcantly associated with
age and antidepressants, but the association with antidepres-
sants was signiﬁcantly stronger than that with age (as judged by
the nonoverlapping conﬁdence intervals of the odds ratios).
Current AT was best predicted by the number of comorbidities
or antidepressants, and these were not signiﬁcantly different in
their association (as judged by the overlapping conﬁdence
intervals of the odds ratios). Disorder in the past data was best
predicted by antidepressants or worse eye VA, but these were
not signiﬁcantly different in their association. Current disorder
was signiﬁcantly associated only with age. Age was signiﬁcantly
associated with past BV or eye movement AT (P ¼ 0.028, Fig.
1A, Table 4) and with current disorder (P ¼ 0.035, Fig. 1B,
Table 4), but this association did not reach signiﬁcance for
current AT or past disorder.
It is notable that the prevalence of a large near exophoria
(Fig. 1D) is signiﬁcantly higher than the prevalence of such a
phoria that shows signs of decompensation (Fig. 2B). Thus,
based on our criteria, the majority of people with a large near
exophoria do appear to be able to compensate for it. Although
not shown, it is also worth noting that 51 patients (10.2%)
reported diplopia at their most recent examination and 33
patients (6.6%) in the past examination.
Univariate (cross-sectional) analysis showed that the only
individual ATs that were signiﬁcantly associated with age were
anomalies of pursuits (Fig. 1I); distance esophoria (Fig. 1F); and
FIGURE 1. Prevalence of BV and eye movement abnormal test results. Past data were from the same patients but approximately 10 years prior to the
current data. (A) Strabismus. (B) Distance or near vertical phoria. (C) Distance phoria >4pd. (D) Near exophoria >8pd. (E) NPC >10cms. (F)
Distance esophoria. (G) Near esophoria. (H) Incomitancy. (I) Anomaly of pursuits. NPC, near point of convergence.
FIGURE 2. Prevalence of BV disorders that were classiﬁed differently from the AT results shown in Figure 1. (A) Decompensated distance
exophoria. (B) Decompensated near exophoria. Decompensated distance exophoria was deﬁned as >4 pd exophoria in the primary position PLUS
abnormalþve fusional reserves or symptoms of diplopia or suppression. Decompensated near exophoria was deﬁned as >8 pd exophoria PLUS NPC
>10 cms or symptoms of diplopia or decreased stereopsis or suppression. pd, prism diopter.
BV and Eye Movement Disorders in Older Adults IOVS j May 2013 j Vol. 54 j No. 5 j 3801
5. exophoria (Fig. 1C) for the current data and anomalies of
pursuits and distance exophoria for the past data (P < 0.05).
Table 5 shows the combined prevalence for all age groups for
any AT or disorder and for the various measures of AT and
disorder that were consistently measured at both visits. This
longitudinal analysis shows that there was no change in the
prevalence of abnormal distance phoria over the 10-year
period, whereas there were signiﬁcant increases in the
prevalence of vertical phoria; near exophoria; remote NPC
(Fig. 1E); and anomalies of pursuits (Table 5). These would
appear to contribute to the increasing prevalence of any BV
and eye movement AT and disorder (also shown in Table 5).
The results of the multivariate regression analysis are shown
in Table 6. Age and use of antidepressants were the factors that
most frequently came into the models, with number of
comorbidities explaining current AT and worse eye VA
explaining some of the variation in past disorder.
The overall prevalence of BV and eye movement ATs and
disorders are high in the older population, ranging from 31% to
51% for any AT and from 17% to 38% for any disorder. As far as
the authors are aware, this is the ﬁrst study giving the
prevalence of a range of BV disorders in older adults and an
additional strength is the longitudinal component of the data. It
is impossible to compare this study precisely with other
studies of the prevalence of BV disorders, as different
deﬁnitions have been used, different conditions included,
and different age groups sampled. However, the previously
reported prevalence of BV disorders is quite high even in
younger adult populations ranging from 15% to 26.7%, if 5% is
added for strabismus.2–10,12,13 Thus, it appears that in clinic
populations, BV disorders have a high prevalence in adults of
all ages. The present study found an additional 3% to 5%
prevalence of incomitancy (see Fig. 1H) and a 1% to 2%
prevalence of anomalies of pursuits (Fig. 1I).
In the present study, there was an association of BV and eye
movement ATs and disorders with age, although it was not
always the best predictor. The use of antidepressants,
comorbidities, and VA in the worse eye were better predictors
than age in some cases (current AT and past disorder; Tables 4,
5). The link with antidepressants is interesting and relevant as
the use of antidepressants is common and increasing in the
older population.42 There are occasional references to associ-
ations between use of antidepressants and speciﬁc BV disorders
in the literature. Gilmartin34
mentions that the use of tricyclic
and related antidepressants may be associated with decompen-
sation of an existing hyperphoria, very occasionally resulting in
reports that certain drugs, including
tricyclic antidepressants and antianxiety drugs (benzodiaze-
pines), may be associated with diplopia due to a breakdown of
heterophoria or more rarely due to extraocular muscle palsy,
gaze palsy, or internuclear ophthalmoplegia. To our knowledge,
this is the ﬁrst study which links the prevalence of general BV
and eye movement disorders to the use of antidepressants.
Similarly, although the association between speciﬁc diseases
(such as, thyroid disease, diabetes, and cerebral vascular
accident) and incomitancy and strabismus is known, we are
not aware of any other studies that speciﬁcally link the
prevalence of general BV disorders with a comorbidity score.
The prevalence of strabismus once a person reaches school
age is quite consistent between studies at approximately
; and we have found a similar result (Fig. 1A). In the
present study, strabismus did not increase signiﬁcantly with
age. The increase of near exophoria with age is in agreement
with the few previous studies that consider the change of
exophoria for presbyopes (for prepresbyopes and early
presbyopia, there is the additional factor of decreasing
accommodation). Yekta et al.15
reported an increase of near
exophoria, associated phoria, and ﬁxation disparity with age
from 10 to 65 years, and that the rate of change appears to be
constant over the prepresbyopic and presbyopic years.
Hrynchak et al.43 found a continued increase of the prevalence
of near exophoria and exotropia well after the onset of
absolute presbyopia. Thus, the present study and that of
Hrynchak et al.43
differ regarding changes in the prevalence of
strabismus at near. This may be because the present study
counted distance and/or near strabismus together (which may
tend to mask the changes that occur speciﬁcally at near),
whereas Hrynchak et al.43
considered only strabismus at near.
However, the two studies are in agreement regarding the trend
TABLE 3. Prevalence (%) of BV and Eye Movement AT Results and Disorders According to Age
AT Results Disorders
Years 50–59 60–69 70–79 80þ 50–59 60–69 70–79 80þ
Past assessment 30.9 35.5 39.8 – 17.3 19.3 23.5 –
Current assessment – 40.5 43.5 51.2 – 26.8 29.8 38.4
Fisher exact test (comparing the same
age, but different groups) P ¼ 0.432 P ¼ 0.505 P ¼ 0.155 P ¼ 0.214
Fisher exact test (comparing the same
group past and current) P ¼ 0.088 P ¼ 0.181 P ¼ 0.046 P ¼ 0.048 P ¼ 0.043 P ¼ 0.004
FIGURE 3. Final prevalence of any AT result or any disorder. (A) Any abnormal test result. (B) Any disorder.
BV and Eye Movement Disorders in Older Adults IOVS j May 2013 j Vol. 54 j No. 5 j 3802
6. of increasing prevalence of exodeviation at near and some of
these exodeviations may be expected to breakdown from a
phoria to a strabismus. Yekta et al.15 point out that the increase
in near exophoria happens gradually over the prepresbyopic
and presbyopic years (i.e., it does not seem to be related to the
provision or increase of a reading addition). Our results
conﬁrm this as all the patients in the current study were
presbyopic, requiring a reading addition.
Although some longitudinal studies of distance phoria in
younger populations show changes with age,44,45
have included older populations show no signiﬁcant change1
(Irving EL, IOVS 2012;53:ARVO E-Abstract 1785). Pickwell,16
a cross-sectional study, found no age trends for prevalence of
distance associated phoria. Our longitudinal analysis is in
agreement that there is no signiﬁcant change of the prevalence
of either distance eso- or exophoria with age.
The increasing prevalence of ATs and disorders with age
seems to be inﬂuenced by an increasing prevalence of vertical
phoria, near exophoria, decreased NPC, and anomalies of
pursuits. Although we did not ﬁnd a signiﬁcant change in the
prevalence of strabismus or incomitancy, the large change in
the prevalence of vertical phorias (3.6%–14.4% over 10 years,
Fig. 1B) might lead to strabismus. Magramm and Schlossman22
reported that 26% of patients aged over 60 years receiving
strabismus surgery had a vertical component to their
strabismus and the majority had strabismus secondary to
disease processes (neuroparalytic, restrictive or as a result of
sensory loss) .
BV problems are common in the older adults, and may
result in reduced stereopsis, which has functional consequenc-
including being a known risk factor for falls in older
However, the management of BV disorders may not
be receiving the attention that it deserves. Magramm and
reported that on average, patients aged over 60
years experienced symptoms (most commonly diplopia and
asthenopia) for a duration of 8 years prior to obtaining surgery
for strabismus. Some of these BV disorders may be treatable,
either with surgery, prismatic correction, or vision therapy that
may be successful in older adults.47,48
vision training for convergence insufﬁciency reduces symp-
toms in presbyopic patients and Cohen and Soden50 report on
a cohort of adults aged over 60 years whose symptoms
associated with convergence insufﬁciency decreased and
whose near point of convergence measurements improved
with in-ofﬁce and home-based visual therapy. However, there
are no randomized clinical trials of the effectiveness of vision
therapy for binocular disorders in older adults, which may be
an area for future study.
We thank Linda Lillakas for editing the text and for creating the
Supported by Vision Services Plan and the Canadian Optometric
Education Trust Fund.
Disclosure: S.J. Leat, None; L.L.-L. Chan, None; P.-D. Maharaj,
None; P.K. Hrynchak, None; A. Mittelstaedt, None; C.M.
Machan, None; E.L. Irving, None
TABLE 5. Combined Prevalence for All Age Groups for AT Results and
Any BV and EM abnormal
test result 35.4 45.0 0.003*
Any BV and EM disorder 20.0 31.6 <0.001*
Strabismus 5.8 6.4 >0.05
Vertical phoria 3.6 14.4 <0.001*
Distance exophoria 2.2 2.4 >0.05
Near exophoria 7.4 12.0 0.018*
NPC >10 6.8 13.8 <0.001*
Distance esophoria 4.4 5.0 >0.05
Near esophoria 3.8 3.4 >0.05
Incomitancy 4.4 3.6 >0.05
Anomaly of pursuits 3.4 7.4 0.005*
exophoria 0.4 1.0 >0.05
exophoria 1.2 1.6 >0.05
EM, eye movement; NPC, near point of convergence.
* Indicates a signiﬁcant difference in prevalence at the P ¼ 0.05
TABLE 6. Models From Forward Multivariate Logistic Regression for
Any AT Result or Disorder
Coefﬁcient P P for Model
Past AT result
Antidepressants 1.17 0.027 0.007
Age 0.02 0.027
Current AT result
Number of comorbidities 0.21 0.010 0.010
Antidepressants 1.45 0.005 0.003
Worse eye VA 1.20 0.037
Age 0.02 0.035 0.034
TABLE 4. Results of Univariate Analysis for Any AT Result and Any
Disorder for Past and Current Data
Odds Ratio (Lower–Upper CI) P
Past AT result
Age 1.02 (1.00–1.05) 0.028*
Number of comorbidities 1.23 (0.99–1.52) 0.066
Antidepressants 3.16 (1.13–8.86) 0.028*
Worse eye VA 2.24 (0.81–6.22) 0.121
Better eye VA 5.22 (0.80–34.1) 0.085
Current AT result
Age 1.02 (0.997–1.04) 0.098
Number of comorbidities 1.23 (1.05–1.44) 0.010*
Antidepressants 5.78 (1.16–4.21) 0.016*
Worse eye VA 2.27 (0.88–5.84) 0.090
Age 1.02 (1.00–1.05) 0.083
Antidepressants 4.26 (1.56–11.7) 0.005*
Worse eye VA 3.28 (1.08–9.97) 0.037*
Age 1.02 (1.00–1.05) 0.035*
Number of comorbidities 1.16 (0.99–1.37) 0.075
Worse eye VA 2.20 (0.84–5.79) 0.109
Better eye VA 2.95 (0.74–12.0) 0.131
Data show those whose probabilities were P < 0.15. Those that are
signiﬁcant at the P ¼ 0.05 level are indicated with *. CI, conﬁdence
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