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Journal of Bodywork & Movement Therapies (2015) xx, 1e6
Available online at www.sciencedirect.com
ScienceDirect journal homepage: www.elsevier.com/jbmt
COHORT FEASIBILITY STUDY
Multifactoral measures of fall risk in the visually impaired population: A pilot study Victoria Graham, PT, DPT, OCS, NCS a,*, Kierstyn Napier-Dovorany, OD, FAAO b,** a b
California State University Northridge, 18111 Nordhoff Street, California, 91330, USA Western University of Health Sciences, College of Optometry, USA
Received 19 March 2015; received in revised form 24 May 2015; accepted 19 June 2015
KEYWORDS Visual impairment; Accidental fall; Risk assessment; Physical examination; Interdisciplinary communication
Summary Objective: To determine the feasibility of taking multiple measures of visual and physical function in adults with visual impairment. A second objective was to obtain preliminary data on risk for falls in this population. Design: Cohort feasibility study. Setting: University ambulatory patient care center and research center. Participants: Convenience sample of community-dwelling men and women over age 18 with visual impairment (n Z 12). Thirteen subjects were enrolled in the study; one was subsequently excluded due to self-reported cognitive decline at time of testing. Subjects were grouped by prospective fall incidence. Interventions: Verbal education. Main outcome measures: Subjective measures of function; objective measures of visual and physical function. Results: Visually impaired adults can safely complete a battery of physical functions to predict fall risk. Recent onset of visual impairment was correlated with higher fall risk [0.53 0.22, p Z 0.04]. Conclusions: It is feasible for an interdisciplinary team to measure risk for falls in adults with a visual impairment. Further investigation is needed to identify predictors of falls in adults of all ages with visual impairment. ª 2015 Elsevier Ltd. All rights reserved.
* Corresponding author. California State University Northridge, 18111 Nordhoff Street, California, 91330, USA. Tel.: þ1 818 677 2346. ** Corresponding author. Western University of Health Sciences, 309 E 2nd St, Pomona, CA 91766, USA. Tel.: þ1 909 706 3887. E-mail addresses: [email protected] (V. Graham), [email protected] (K. Napier-Dovorany). http://dx.doi.org/10.1016/j.jbmt.2015.06.012 1360-8592/ª 2015 Elsevier Ltd. All rights reserved.
Please cite this article in press as: Graham, V., Napier-Dovorany, K., Multifactoral measures of fall risk in the visually impaired population: A pilot study, Journal of Bodywork & Movement Therapies (2015), http://dx.doi.org/10.1016/j.jbmt.2015.06.012
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Introduction Intervention across the lifespan is ideal to maximize quality of life for people with visual impairment (Leissner et al., 2014). The World Health Organization (WHO) classifies visual impairment as a decrease in visual acuity or a reduction in visual field (WHO, 2015). People with visual impairment may experience more handicap or disability, specifically related to mobility problems and reduced participation (Owsley et al., 2009). Visual impairment is on the rise due to increasing incidence in the United States (Ko et al., 2012). This population may seek care from a variety of healthcare providers including physicians, rehabilitation specialists, and eye care providers. The low vision population has different challenges with movement and navigating the environment than the sighted population. A person without visual impairment constantly scans the area, gathering information to formulate a motor plan to avoid obstacles. People with visual impairment use a variety of approaches, including compensatory tactile strategies to guide their movement plan (Wade and Jones, 1997). Visual impairment causes problems across the lifespan, as it is linked to fall risk in the elderly (Lord and Dayhew, 2001; Kulmala et al., 2008), and poor health in younger adults (Leissner et al., 2014). Among the elderly, multifactoral risk factors for falls include medicine side-effects, cognitive decline, loss of mobility, and visual impairment (Graafmans et al., 1996; Tinetti et al., 1988). Visual impairment in younger adults is linked to inactivity, higher body mass index (BMI), and poor balance reactions (Leissner et al., 2014; Ramulu, 2012) as well as an increase in chronic health conditions (Leissner et al., 2014). All the above mentioned factors can lead to falls (Wu et al., 2012; Fjeldstad et al., 2008). The level and cause of visual impairment leading to fall risk is less clear, as characteristics of visual impairment remains poorly defined in most fall risk and balance studies. In one study, a threshold of 20/40 acuity correlated to impaired independence in activities of daily living (ADLs), instrumental activities of daily living (IADLS), and mobility, but not falls specifically (Laitinen et al., 2007). There are inconclusive studies investigating the impact of specific visual interventions on balance, mobility and participation (Skelton et al., 2013; Virgili and Rubin, 2010). Intervention appears to reduce fall risk in this population; however a standard approach is not defined. The aim of this study was to determine the feasibility of taking multiple measures of visual and physical function to better understand fall risk and prevention in the adults 18 years or older with visual impairment. A second aim was to obtain preliminary data on fall risk in this population.
Methods Participants Subjects were recruited from a convenience sample of patients at the Western University Eye Care Center’s Vision Rehabilitation Clinic. Subjects were excluded if they were under 18 years of age or were non-ambulatory. Thirteen subjects met the inclusion criteria and were enrolled in the
V. Graham, K. Napier-Dovorany study; one was subsequently excluded due to self-reported cognitive decline at time of testing. Each subject gave signed consent to participate in the study. Trained examiners assisted with form completion and all testing. This protocol was approved by the Western University Institutional Review Board and the tenants of the Declaration of Helsinki were followed.
Procedures Subjects of both genders aged 20e86 underwent a battery of tests to measure visual function, subjective measures of function, and physical function. The investigators in this study were a low vision optometrist and a physical therapist, who supervised or performed all testing. In a separate preliminary study, the investigators trained each other to perform all measures, and then compared results for the Four Square Step Test (FSST) and the Walking Speed Test. We found good reliability between each other (p Z 0.96, unpublished data). As a result of this, we trained student from our own individual professional programs to perform testing under direct supervision. The physical therapist supervised or performed all physical testing and the optometrist supervised or performed all measures of vision function. Subjects completed all tests within a 2 h timeframe. Visual acuity was measured using a separate retroilluminated Early Treatment of Diabetic Retinopathy Study (ETDRS) chart for each eye and a separate chart for both eyes together (OU) at 4 m, or 1 m if the subject could not read the top line. If the subject still could not read the top line, the eye was evaluated for light perception acuity. Subjects were asked to read every letter on the chart until they could not read any more letters. Total number of letters read was ultimately converted into Snellen equivalent and is reported in this study as 20/X, with the denominator representing the level of vision. Higher denominator values represent worse visual acuity. Binocular (both eyes together) contrast sensitivity was measured with the Mars contrast sensitivity chart according to manufacturer instructions. Monocular (one eye only) visual fields were determined by a chart review of patients’ medical record (measured either by confrontation method, Humphrey Visual Field Analyzer or Octopus 900 Perimeter) and are reported as full or constricted. Subjective function was assessed by oral history and with 2 questionnaires: Activity Balance Confidence Scale (ABC), and the Visual Functioning Questionnaire-25 (VFQ). The ABC is a validated instrument to describe subjects’ perceived confidence with mobility (Lajoie and Gallagher, 2004; Powell and Meyers, 1995; Meyers et al., 1998). This tool is validated in multiple populations as predictive of future falls. The short (25 questions) version of the VFQ is a validated instrument developed by Mangione et al. (2001) to measure self-reported quality of vision and health in persons with chronic eye disease. Subjects performed three tests of physical function: Walking Speed Test, Four Square Step Test (see Fig. 1), and the NeuroCom Balance Master Sensory Organization Test (see Fig. 2). Examiners used either a safety belt around the waist or a harness during all mobility tests to prevent falls.
Please cite this article in press as: Graham, V., Napier-Dovorany, K., Multifactoral measures of fall risk in the visually impaired population: A pilot study, Journal of Bodywork & Movement Therapies (2015), http://dx.doi.org/10.1016/j.jbmt.2015.06.012
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Multifactoral measures of fall risk in the visually impaired population
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of balance. Subjects were allowed to use handheld assistive gait devices such as a cane or walker. The NeuroCom Balance Master Sensory Organization Test (SOT) (Wade and Jones, 1997) measured standing postural sway and reaction time with force plates on the floor (see Fig. 2). During the SOT, subjects stood for several minutes while the floor and/or walls moved around them. We followed the protocol as described by Napier-Dovorany and Graham 2013 for all mobility tests. At the end of the in-person session, all findings were reviewed in detail with each subject using lay terminology by the physical therapist and optometrist. Subjects were notified and counseled on individualized strategies to prevent falls when needed. Monthly follow up occurred for the subsequent 6 months via home phone calls to determine any incidence of falls or loss of balance. Subjects were asked to report incidence of loss of balance without fall, falls without injury or falls with injury. They were also queried regarding strategies used to prevent falls if balance loss was reported.
Statistics Figure 1
Subject performing the Four Square Step Test.
An independent samples t-test was run to determine if there were differences in fall report within 6 months after study onset. Statistics were generated using: International Business Machine Statistical Package for the Social Sciences (IBM SPSS Statistics) 22.0 and are reported as mean difference standard error. An equal number of males and females were in each group.
Results
Figure 2
Smart Balance Masterª sensory organization test.
The Walking Speed Test is a clinical measure of normal gait velocity (Fritz and Lusardi, 2009). Subjects were asked to walk 10 m at their normal pace. The middle five meters were timed to minimize acceleration and deceleration and therefore capture constant velocity. Subjects performed the FSST (Dite and Temple, 2002) to directly assess dynamic balance (see Fig. 1). Subjects used a pattern to step over four canes placed in an X on the floor. Subjects were given the following instructions: “Try to complete the sequence as fast as possible without touching the sticks. Both feet must make contact with the floor in each square. If possible, face forward during the entire sequence.” For the test, one practice and up to four trials were allowed. Scoring began when the first foot contacted the floor in square two. All trials were timed, with notation of any episodes of contacting a cane on the floor, turning, or loss
All 12 subjects completed testing with no adverse events. Four to six months of phone follow-up was completed for each subject. There were over 10 different ocular diseases causing visual impairment in this study. Five subjects reported falling during the 6 months prior to study onset, with an average of 1.8 falls each. Subject demographic, subjective data and functional data is displayed in Table 1. Average visual acuity in both eyes for the group of subjects was equivalent to 20/190, indicating central vision was about 10 times worse than the non-impaired population. Average contrast sensitivity in both eyes was 1.25 log, which is below the range for the population of 1.52e1.92 log. Visual fields were full in 4 subjects and constricted in at least 1 eye in 8 subjects. The average result of the Activities Based Confidence questionnaire was 78%, indicating an overall good level of confidence about balance, as a score below 67% represents an increased fall risk in the sighted population (Lajoie and Gallagher, 2004). In our subjects, 3 people had scores below 67%. The average result of the Visual Functioning Questionnaire was 54.8 out of 100 possible points, where 100 represents no self-reported disability related to vision. The average time for the fastest Four Square Step Test result was 10.9 s. Four subjects scored slower than the normally sighted population average of 11 s. The average time for the 5 m walking speed was 4.63 s which is within normal range compared to the normally sighted population average of 5 s. The average composite score for the Sensory
Please cite this article in press as: Graham, V., Napier-Dovorany, K., Multifactoral measures of fall risk in the visually impaired population: A pilot study, Journal of Bodywork & Movement Therapies (2015), http://dx.doi.org/10.1016/j.jbmt.2015.06.012
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V. Graham, K. Napier-Dovorany Table 1
Demographic, subjective data, and functional data.
Gender (Male) Age (Years) Race Caucasian Hispanic African American Asian Prior falls (Number) Ambulatory status Unaided Support cane Visual Acuity OU Contrast sensitivity OU (log) Visual field-constricted (at least 1 eye) ABC (%) VFQ-25 (100 max) Walking speed (sec) FSST (sec) SOT (Composite Score)
No fall (after intervention) n Z 8
Fall (after intervention) (n Z 4)
Frequency
Frequency
Average (range)
4
Average (range)
2 48.63 (21e86)
3 3 1 1
56.5 (20e84) 2 2 0 0
1.13 (0e5) 6 2
3 (0e5) 2 2
20/210 (20/90e20/800) 1.35 (0.4e1.68) 5
20/160 (20/50e20/320) 1.07 (0.68e1.4) 3
78.52 56.22 4.58 10.65 64.5
(45e97.5) (42.67e65.59) (3.53e6.13) (8.91e13.91) (49e80)
76.88 51.96 4.73 11.39 62.5
(62.5e95) (40.24e62.92) (4.17e6.09) (9.46e13.53) (32e84)
*OU Z both eyes, ABC Z Activities Balance Confidence Scale, VFQ-25 Z Questionnaire 25 question version, FSST Z Four Square Step Test, SOT Z Sensory Organization Test.
Organization Test was 63.8 for standing balance under three different sensory conditions. This represents more sway than the average age and sex matched normally sighted population score of 68.8. In our 12 subjects, six were participating in exercise programs, and encouraged to add balance specific activities such as tai chi or yoga. Five were advised to seek additional care to address specific limitations placing them at increased risk for falls. These limitations were persistent vertigo, knee pain, and poor use of ankle strategies to maintain balance. Four subjects experienced a fall (with or without injury) and eight subjects did not in the 6 months after data collection. Of the four subjects reporting falls, two were originally advised to seek physical therapy due to vertigo, and neither followed up. Both fell due to dizziness, one during month two and the other month five. The other two subjects who reported falls were both originally advised to continue exercise programs and integrate balance exercises during session one, and they both reported compliance with these activities during subsequent calls. One began walking his dog daily, with a fall and minor injury reported during month five, without reason given. The last subject with a fall reported was skateboarding regularly, and did take our advice to begin wearing a helmet. His fall was during skateboarding and included no injury. There were no statistically significant differences between fallers (n Z 4) and non-fallers (n Z 8) on any variables except that the group of fallers tended to have a smaller percentage of their life with visual impairment than the non-fallers [0.53 0.22, p Z 0.04], see Fig. 3. Of the 4 subjects with falls, 3 had a more recent onset of visual impairment, living only 1e5 years with their visual impairment. The fourth subject lived all his 20 years with a visual
impairment but reported high levels of physical activity, sustaining multiple falls while skateboarding. If this outlier is removed, the significance of the finding increases [0.77 0.17, p Z 0.002].
Discussion This was a pilot study with very few exclusion criteria. As such, this study had a small number of subjects with a large
Figure 3 Subjects were grouped by self-report of falls sustained, with or without injury, after study commencement. The scale is percent of lifetime with visual impairment, regardless of age. The black bars indicate the subjects that sustained a fall after the study commenced; the shaded bars indicate the subjects without fall report after the study commenced.
Please cite this article in press as: Graham, V., Napier-Dovorany, K., Multifactoral measures of fall risk in the visually impaired population: A pilot study, Journal of Bodywork & Movement Therapies (2015), http://dx.doi.org/10.1016/j.jbmt.2015.06.012
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Multifactoral measures of fall risk in the visually impaired population age range and diverse etiology of visual impairment. Four subjects in the study had systemic conditions that could affect balance including: knee replacement, weak ankles, vertigo, hydrocephalus and subdural hematoma. Five subjects were taking medications with side effects that could affect balance such as vertigo, hypotension, muscle weakness, or blur. These factors did not affect the feasibility of performing this battery of tests, our primary aim of the study. The tests described above were safe and feasible for an interdisciplinary team consisting of a physical therapist and an optometrist to perform in this population. Our second aim was to investigate if there were any risk factors associated with fall risk in this study. We found that recent onset of visual impairment may be a predictor of prospective falls, as it was a statistically significant potential indicator of fall risk. More research is needed to confirm this finding. Subjects were educated prior to study completion by both the physical therapist and optometrist researchers regarding fall risk with specific, personalized advice to reduce fall risk as we felt the ethical obligation outweighed research value. Subjects were interested in their results and recommendations for improved function. Common questions at the end of the in-person session included data about their visual and functional results, normal expectations for their specific visual impairment, how to prevent falls, ways to become more fit and active, and methods of accessing the community. Subjects were interested in how research findings would predict future function and impact their current mobility strategies which included cane use, route planning, fall prevention, and safety strategies. We referred subjects identified as at a risk for falls to appropriate providers and made specific recommendations for altered strategies to enhance balance and mobility based on findings, including use of supportive devices such as walkers. Subsequent follow up calls made during the next six months allowed for ongoing discussion of balance, falls and strategies. During each monthly call, subjects who described loss of balance with or without falls were asked about each incidence specifically. This offered an opportunity for researchers to provide feedback regarding efficacy of self - selected strategies. As a result of this monthly dialog, a pattern of behavior became discernable, and through discussion, several subjects became willing to seek additional assistance as originally advised. With our small pilot study, we identified four themes which may be beneficial for body work practitioners caring for visually impaired individuals. These themes include: 1) the need to assess multiple factors underlying fall risk, 2) initial resistance to behavioral change, 3) positive response to ongoing education when provided with specific feedback regarding vision function, and 4) need for visual compensatory strategies to improve mobility. Rehabilitation of the musculoskeletal system dysfunction often involves ongoing care that allows a close bond between the patient and provider. This ongoing contact can be used to assess behavior, and counsel when behaviors are not effective is recommended. People with new onset of visual impairment may be at higher risk for associated health risks including inactivity, obesity and falls. Referral to a professional with skills and training specific for VI strategies is indicated due
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to unique needs for training and adjustment. In the United States these professions include those occupational therapists and optometrists who have specialized training and clinical expertise in working with people with visual impairments. In addition, there are professionals trained specifically to work only with people with visual impairments, such as orientation and mobility specialists who train individuals on safe travel throughout the community.
Conclusion All professions that incorporate body movement should be aware of potential mobility issues in patients with a visual impairment. Professionals may need to alter treatment or instructions for this population. Fall risk evaluation should be performed on people with a visual impairment, either by an appropriately trained optician or by referral to an appropriate mobility specialist who is experienced in working with this population. Best practice requires coordinated, multidisciplinary care for those individuals at high risk of falling. Fall risk intervention across the lifespan is ideal for people with visual impairment to reduce injury and maximize quality of life. Further research in this area is important. Baseline normative measures must be established for this population and further investigation is needed to provide more evidence that time with visual impairment is a predictor of prospective falls, as well as to identify other predictors of falls in adults with visual impairment. We recommend an interdisciplinary approach to studying and managing fall risk in this population.
Financial support None.
Conflicts of interest None.
References Dite, W., Temple, V.A., 2002. A clinical test of stepping and change of direction to identify multiple falling in older adults. Arch. Phys. Med. Rehabil. 83 (11), 1566e1571. Fjeldstad, C., Fjeldstad, A.S., Acree, L.S., Nickel, K.J., Gardner, A.W., 2008. The influence of obesity on falls and quality of life. Dyn. Med. 7, 4. Fritz, S., Lusardi, M., 2009. White paper: “Walking speed: the sixth vital sign”. J. Geriatr. Phys. Ther. 32 (2), 46e49. Graafmans, W.C., Ooms, M.E., Hofstee, H.M., Bezemer, P.D., Bouter, L.M., Lips, P., 1996. Falls in the elderly: a prospective study of risk factors and risk profiles. Am. J. Epidemiol. 143 (11), 1129e1135. Ko, F., Vitale, S., Chou, C.F., Cotch, M.F., Saaddine, J., Friedman, D.S., 2012. Prevalence of nonrefractive visual impairment in US adults and associated risk factors, 1999e2002 and 2005e2008. Nonrefractive Visual Impairment in US Adults JAMA: J. Am. Med. Assoc. 308 (22), 2361.
Please cite this article in press as: Graham, V., Napier-Dovorany, K., Multifactoral measures of fall risk in the visually impaired population: A pilot study, Journal of Bodywork & Movement Therapies (2015), http://dx.doi.org/10.1016/j.jbmt.2015.06.012
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6 Kulmala, J., Era, P., Pa ¨rssinen, O., Sakari, R., Sipila ¨, S., Rantanen, T., Heikkinen, E., 2008. Lowered vision as a risk factor for injurious accidents in older people. Aging Clin. Exp. Res. 20, 25e30, 2. Laitinen, A., Sainio, P., Koskinen, S., Rudanko, S.L., Laatikainen, L., Aromaa, A., 2007. The association between visual acuity and functional limitations:findings from a nationally representative population survey. Ophthalmic Epidemiol. 14 (6), 333e342. Lajoie, Y., Gallagher, S.P., 2004. Predicting falls within the elderly community: comparison of postural sway, reaction time, the Berg balance scale and the Activities-specific Balance Confidence (ABC) scale for comparing fallers and non-fallers. Arch. Gerontol. Geriatr. 38 (1), 11e26. Leissner, J., Coenen, M., Froehlich, S., Loyola, D., Cieza, A., 2014. What explains health in persons with visual impairment? Health Qual. Life Outcomes 12, 65. Lord, S.R., Dayhew, J., 2001. Visual risk factors for falls in older people. J. Am. Geriatr. Soc. 49, 508e515. Mangione, C.M., Lee, P.P., Gutierrez, P.R., Spritzer, K., Berry, S., Hays, R.D., 2001. Development of the 25-item national eye Institute visual function questionnaire. Arch. Ophthalmol. 119 (7), 1050e1058. Meyers, A.M., Fletcher, P.C., Myers, A.H., Sherk, W., 1998. Discriminative and evaluative properties of the Activitiesspecific Balance Confidence (ABC) scale. J. Gerontol. A Biol. Sci. Med. Sci. 53, M287eM294. Napier-Dovorany, K., Graham, V., 2013. Evaluating fall risk in people with low vision: a case series. Optom. Vis. Perf. 1 (3), 158e170.
V. Graham, K. Napier-Dovorany Owsley, C., McGwin, G., Lee, P., Wasserman, N., Searcey, K., 2009 May. Characteristics of low vision rehabilitation services in the United States. Arch. Ophthalmol. 127 (5), 681e689. Powell, L.E., Myers, A.M., 1995. The Activities-specific Balance Confidence (ABC) scale. J. Gerontol. Med. Sci. 50, M28eM34. Ramulu, P.Y., van Landingham, S.W., Massof, R.W., Chan, E.S., Ferrucci, L., Friedman, D.S., 2012. Fear of falling and visual field loss from glaucoma. Ophthalmology 119 (7), 1352e1358, 2. Skelton, D.A., Howe, T.E., Ballinger, C., Neil, F., Palmer, S., Gray, L., 2013 Jun 5. Environmental and behavioural interventions for reducing physical activity limitation in community-dwelling visually impaired older people. Cochrane Database Syst. Rev. 6, CD009233. Tinetti, M., Speechley, M., Ginter, S., 1988. Risk factors for falls among elderly persons living in the community. N. Engl. J. Med. 319, 1701e1707. Virgili, G., Rubin, G., 2010 May 12. Orientation and mobility training for adults with low vision. Cochrane Database Syst. Rev. 5, CD003925. Wade, M.G., Jones, G., 1997. The role of vision and spatial orientation in the maintenance of posture. Phys. Ther. 77, 619e628. World Health Organization, 2015 May 20. International Statistical Classification of Disease Chapter VII H54 Blindness and Low Vision [Internet]. Available from: http://www.who.int/ classifications/icd/en/. Wu, X., Lockhart, T., Yeoh, H., 2012. Effects of obesity on slipinduced fall risks among young male adults. J. Biomech. 45, 1042e1047.
Please cite this article in press as: Graham, V., Napier-Dovorany, K., Multifactoral measures of fall risk in the visually impaired population: A pilot study, Journal of Bodywork & Movement Therapies (2015), http://dx.doi.org/10.1016/j.jbmt.2015.06.012
MODEL
Journal of Bodywork & Movement Therapies (2015) xx, 1e6
Available online at www.sciencedirect.com
ScienceDirect journal homepage: www.elsevier.com/jbmt
COHORT FEASIBILITY STUDY
Multifactoral measures of fall risk in the visually impaired population: A pilot study Victoria Graham, PT, DPT, OCS, NCS a,*, Kierstyn Napier-Dovorany, OD, FAAO b,** a b
California State University Northridge, 18111 Nordhoff Street, California, 91330, USA Western University of Health Sciences, College of Optometry, USA
Received 19 March 2015; received in revised form 24 May 2015; accepted 19 June 2015
KEYWORDS Visual impairment; Accidental fall; Risk assessment; Physical examination; Interdisciplinary communication
Summary Objective: To determine the feasibility of taking multiple measures of visual and physical function in adults with visual impairment. A second objective was to obtain preliminary data on risk for falls in this population. Design: Cohort feasibility study. Setting: University ambulatory patient care center and research center. Participants: Convenience sample of community-dwelling men and women over age 18 with visual impairment (n Z 12). Thirteen subjects were enrolled in the study; one was subsequently excluded due to self-reported cognitive decline at time of testing. Subjects were grouped by prospective fall incidence. Interventions: Verbal education. Main outcome measures: Subjective measures of function; objective measures of visual and physical function. Results: Visually impaired adults can safely complete a battery of physical functions to predict fall risk. Recent onset of visual impairment was correlated with higher fall risk [0.53 0.22, p Z 0.04]. Conclusions: It is feasible for an interdisciplinary team to measure risk for falls in adults with a visual impairment. Further investigation is needed to identify predictors of falls in adults of all ages with visual impairment. ª 2015 Elsevier Ltd. All rights reserved.
* Corresponding author. California State University Northridge, 18111 Nordhoff Street, California, 91330, USA. Tel.: þ1 818 677 2346. ** Corresponding author. Western University of Health Sciences, 309 E 2nd St, Pomona, CA 91766, USA. Tel.: þ1 909 706 3887. E-mail addresses: [email protected] (V. Graham), [email protected] (K. Napier-Dovorany). http://dx.doi.org/10.1016/j.jbmt.2015.06.012 1360-8592/ª 2015 Elsevier Ltd. All rights reserved.
Please cite this article in press as: Graham, V., Napier-Dovorany, K., Multifactoral measures of fall risk in the visually impaired population: A pilot study, Journal of Bodywork & Movement Therapies (2015), http://dx.doi.org/10.1016/j.jbmt.2015.06.012
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Introduction Intervention across the lifespan is ideal to maximize quality of life for people with visual impairment (Leissner et al., 2014). The World Health Organization (WHO) classifies visual impairment as a decrease in visual acuity or a reduction in visual field (WHO, 2015). People with visual impairment may experience more handicap or disability, specifically related to mobility problems and reduced participation (Owsley et al., 2009). Visual impairment is on the rise due to increasing incidence in the United States (Ko et al., 2012). This population may seek care from a variety of healthcare providers including physicians, rehabilitation specialists, and eye care providers. The low vision population has different challenges with movement and navigating the environment than the sighted population. A person without visual impairment constantly scans the area, gathering information to formulate a motor plan to avoid obstacles. People with visual impairment use a variety of approaches, including compensatory tactile strategies to guide their movement plan (Wade and Jones, 1997). Visual impairment causes problems across the lifespan, as it is linked to fall risk in the elderly (Lord and Dayhew, 2001; Kulmala et al., 2008), and poor health in younger adults (Leissner et al., 2014). Among the elderly, multifactoral risk factors for falls include medicine side-effects, cognitive decline, loss of mobility, and visual impairment (Graafmans et al., 1996; Tinetti et al., 1988). Visual impairment in younger adults is linked to inactivity, higher body mass index (BMI), and poor balance reactions (Leissner et al., 2014; Ramulu, 2012) as well as an increase in chronic health conditions (Leissner et al., 2014). All the above mentioned factors can lead to falls (Wu et al., 2012; Fjeldstad et al., 2008). The level and cause of visual impairment leading to fall risk is less clear, as characteristics of visual impairment remains poorly defined in most fall risk and balance studies. In one study, a threshold of 20/40 acuity correlated to impaired independence in activities of daily living (ADLs), instrumental activities of daily living (IADLS), and mobility, but not falls specifically (Laitinen et al., 2007). There are inconclusive studies investigating the impact of specific visual interventions on balance, mobility and participation (Skelton et al., 2013; Virgili and Rubin, 2010). Intervention appears to reduce fall risk in this population; however a standard approach is not defined. The aim of this study was to determine the feasibility of taking multiple measures of visual and physical function to better understand fall risk and prevention in the adults 18 years or older with visual impairment. A second aim was to obtain preliminary data on fall risk in this population.
Methods Participants Subjects were recruited from a convenience sample of patients at the Western University Eye Care Center’s Vision Rehabilitation Clinic. Subjects were excluded if they were under 18 years of age or were non-ambulatory. Thirteen subjects met the inclusion criteria and were enrolled in the
V. Graham, K. Napier-Dovorany study; one was subsequently excluded due to self-reported cognitive decline at time of testing. Each subject gave signed consent to participate in the study. Trained examiners assisted with form completion and all testing. This protocol was approved by the Western University Institutional Review Board and the tenants of the Declaration of Helsinki were followed.
Procedures Subjects of both genders aged 20e86 underwent a battery of tests to measure visual function, subjective measures of function, and physical function. The investigators in this study were a low vision optometrist and a physical therapist, who supervised or performed all testing. In a separate preliminary study, the investigators trained each other to perform all measures, and then compared results for the Four Square Step Test (FSST) and the Walking Speed Test. We found good reliability between each other (p Z 0.96, unpublished data). As a result of this, we trained student from our own individual professional programs to perform testing under direct supervision. The physical therapist supervised or performed all physical testing and the optometrist supervised or performed all measures of vision function. Subjects completed all tests within a 2 h timeframe. Visual acuity was measured using a separate retroilluminated Early Treatment of Diabetic Retinopathy Study (ETDRS) chart for each eye and a separate chart for both eyes together (OU) at 4 m, or 1 m if the subject could not read the top line. If the subject still could not read the top line, the eye was evaluated for light perception acuity. Subjects were asked to read every letter on the chart until they could not read any more letters. Total number of letters read was ultimately converted into Snellen equivalent and is reported in this study as 20/X, with the denominator representing the level of vision. Higher denominator values represent worse visual acuity. Binocular (both eyes together) contrast sensitivity was measured with the Mars contrast sensitivity chart according to manufacturer instructions. Monocular (one eye only) visual fields were determined by a chart review of patients’ medical record (measured either by confrontation method, Humphrey Visual Field Analyzer or Octopus 900 Perimeter) and are reported as full or constricted. Subjective function was assessed by oral history and with 2 questionnaires: Activity Balance Confidence Scale (ABC), and the Visual Functioning Questionnaire-25 (VFQ). The ABC is a validated instrument to describe subjects’ perceived confidence with mobility (Lajoie and Gallagher, 2004; Powell and Meyers, 1995; Meyers et al., 1998). This tool is validated in multiple populations as predictive of future falls. The short (25 questions) version of the VFQ is a validated instrument developed by Mangione et al. (2001) to measure self-reported quality of vision and health in persons with chronic eye disease. Subjects performed three tests of physical function: Walking Speed Test, Four Square Step Test (see Fig. 1), and the NeuroCom Balance Master Sensory Organization Test (see Fig. 2). Examiners used either a safety belt around the waist or a harness during all mobility tests to prevent falls.
Please cite this article in press as: Graham, V., Napier-Dovorany, K., Multifactoral measures of fall risk in the visually impaired population: A pilot study, Journal of Bodywork & Movement Therapies (2015), http://dx.doi.org/10.1016/j.jbmt.2015.06.012
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Multifactoral measures of fall risk in the visually impaired population
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of balance. Subjects were allowed to use handheld assistive gait devices such as a cane or walker. The NeuroCom Balance Master Sensory Organization Test (SOT) (Wade and Jones, 1997) measured standing postural sway and reaction time with force plates on the floor (see Fig. 2). During the SOT, subjects stood for several minutes while the floor and/or walls moved around them. We followed the protocol as described by Napier-Dovorany and Graham 2013 for all mobility tests. At the end of the in-person session, all findings were reviewed in detail with each subject using lay terminology by the physical therapist and optometrist. Subjects were notified and counseled on individualized strategies to prevent falls when needed. Monthly follow up occurred for the subsequent 6 months via home phone calls to determine any incidence of falls or loss of balance. Subjects were asked to report incidence of loss of balance without fall, falls without injury or falls with injury. They were also queried regarding strategies used to prevent falls if balance loss was reported.
Statistics Figure 1
Subject performing the Four Square Step Test.
An independent samples t-test was run to determine if there were differences in fall report within 6 months after study onset. Statistics were generated using: International Business Machine Statistical Package for the Social Sciences (IBM SPSS Statistics) 22.0 and are reported as mean difference standard error. An equal number of males and females were in each group.
Results
Figure 2
Smart Balance Masterª sensory organization test.
The Walking Speed Test is a clinical measure of normal gait velocity (Fritz and Lusardi, 2009). Subjects were asked to walk 10 m at their normal pace. The middle five meters were timed to minimize acceleration and deceleration and therefore capture constant velocity. Subjects performed the FSST (Dite and Temple, 2002) to directly assess dynamic balance (see Fig. 1). Subjects used a pattern to step over four canes placed in an X on the floor. Subjects were given the following instructions: “Try to complete the sequence as fast as possible without touching the sticks. Both feet must make contact with the floor in each square. If possible, face forward during the entire sequence.” For the test, one practice and up to four trials were allowed. Scoring began when the first foot contacted the floor in square two. All trials were timed, with notation of any episodes of contacting a cane on the floor, turning, or loss
All 12 subjects completed testing with no adverse events. Four to six months of phone follow-up was completed for each subject. There were over 10 different ocular diseases causing visual impairment in this study. Five subjects reported falling during the 6 months prior to study onset, with an average of 1.8 falls each. Subject demographic, subjective data and functional data is displayed in Table 1. Average visual acuity in both eyes for the group of subjects was equivalent to 20/190, indicating central vision was about 10 times worse than the non-impaired population. Average contrast sensitivity in both eyes was 1.25 log, which is below the range for the population of 1.52e1.92 log. Visual fields were full in 4 subjects and constricted in at least 1 eye in 8 subjects. The average result of the Activities Based Confidence questionnaire was 78%, indicating an overall good level of confidence about balance, as a score below 67% represents an increased fall risk in the sighted population (Lajoie and Gallagher, 2004). In our subjects, 3 people had scores below 67%. The average result of the Visual Functioning Questionnaire was 54.8 out of 100 possible points, where 100 represents no self-reported disability related to vision. The average time for the fastest Four Square Step Test result was 10.9 s. Four subjects scored slower than the normally sighted population average of 11 s. The average time for the 5 m walking speed was 4.63 s which is within normal range compared to the normally sighted population average of 5 s. The average composite score for the Sensory
Please cite this article in press as: Graham, V., Napier-Dovorany, K., Multifactoral measures of fall risk in the visually impaired population: A pilot study, Journal of Bodywork & Movement Therapies (2015), http://dx.doi.org/10.1016/j.jbmt.2015.06.012
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V. Graham, K. Napier-Dovorany Table 1
Demographic, subjective data, and functional data.
Gender (Male) Age (Years) Race Caucasian Hispanic African American Asian Prior falls (Number) Ambulatory status Unaided Support cane Visual Acuity OU Contrast sensitivity OU (log) Visual field-constricted (at least 1 eye) ABC (%) VFQ-25 (100 max) Walking speed (sec) FSST (sec) SOT (Composite Score)
No fall (after intervention) n Z 8
Fall (after intervention) (n Z 4)
Frequency
Frequency
Average (range)
4
Average (range)
2 48.63 (21e86)
3 3 1 1
56.5 (20e84) 2 2 0 0
1.13 (0e5) 6 2
3 (0e5) 2 2
20/210 (20/90e20/800) 1.35 (0.4e1.68) 5
20/160 (20/50e20/320) 1.07 (0.68e1.4) 3
78.52 56.22 4.58 10.65 64.5
(45e97.5) (42.67e65.59) (3.53e6.13) (8.91e13.91) (49e80)
76.88 51.96 4.73 11.39 62.5
(62.5e95) (40.24e62.92) (4.17e6.09) (9.46e13.53) (32e84)
*OU Z both eyes, ABC Z Activities Balance Confidence Scale, VFQ-25 Z Questionnaire 25 question version, FSST Z Four Square Step Test, SOT Z Sensory Organization Test.
Organization Test was 63.8 for standing balance under three different sensory conditions. This represents more sway than the average age and sex matched normally sighted population score of 68.8. In our 12 subjects, six were participating in exercise programs, and encouraged to add balance specific activities such as tai chi or yoga. Five were advised to seek additional care to address specific limitations placing them at increased risk for falls. These limitations were persistent vertigo, knee pain, and poor use of ankle strategies to maintain balance. Four subjects experienced a fall (with or without injury) and eight subjects did not in the 6 months after data collection. Of the four subjects reporting falls, two were originally advised to seek physical therapy due to vertigo, and neither followed up. Both fell due to dizziness, one during month two and the other month five. The other two subjects who reported falls were both originally advised to continue exercise programs and integrate balance exercises during session one, and they both reported compliance with these activities during subsequent calls. One began walking his dog daily, with a fall and minor injury reported during month five, without reason given. The last subject with a fall reported was skateboarding regularly, and did take our advice to begin wearing a helmet. His fall was during skateboarding and included no injury. There were no statistically significant differences between fallers (n Z 4) and non-fallers (n Z 8) on any variables except that the group of fallers tended to have a smaller percentage of their life with visual impairment than the non-fallers [0.53 0.22, p Z 0.04], see Fig. 3. Of the 4 subjects with falls, 3 had a more recent onset of visual impairment, living only 1e5 years with their visual impairment. The fourth subject lived all his 20 years with a visual
impairment but reported high levels of physical activity, sustaining multiple falls while skateboarding. If this outlier is removed, the significance of the finding increases [0.77 0.17, p Z 0.002].
Discussion This was a pilot study with very few exclusion criteria. As such, this study had a small number of subjects with a large
Figure 3 Subjects were grouped by self-report of falls sustained, with or without injury, after study commencement. The scale is percent of lifetime with visual impairment, regardless of age. The black bars indicate the subjects that sustained a fall after the study commenced; the shaded bars indicate the subjects without fall report after the study commenced.
Please cite this article in press as: Graham, V., Napier-Dovorany, K., Multifactoral measures of fall risk in the visually impaired population: A pilot study, Journal of Bodywork & Movement Therapies (2015), http://dx.doi.org/10.1016/j.jbmt.2015.06.012
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Multifactoral measures of fall risk in the visually impaired population age range and diverse etiology of visual impairment. Four subjects in the study had systemic conditions that could affect balance including: knee replacement, weak ankles, vertigo, hydrocephalus and subdural hematoma. Five subjects were taking medications with side effects that could affect balance such as vertigo, hypotension, muscle weakness, or blur. These factors did not affect the feasibility of performing this battery of tests, our primary aim of the study. The tests described above were safe and feasible for an interdisciplinary team consisting of a physical therapist and an optometrist to perform in this population. Our second aim was to investigate if there were any risk factors associated with fall risk in this study. We found that recent onset of visual impairment may be a predictor of prospective falls, as it was a statistically significant potential indicator of fall risk. More research is needed to confirm this finding. Subjects were educated prior to study completion by both the physical therapist and optometrist researchers regarding fall risk with specific, personalized advice to reduce fall risk as we felt the ethical obligation outweighed research value. Subjects were interested in their results and recommendations for improved function. Common questions at the end of the in-person session included data about their visual and functional results, normal expectations for their specific visual impairment, how to prevent falls, ways to become more fit and active, and methods of accessing the community. Subjects were interested in how research findings would predict future function and impact their current mobility strategies which included cane use, route planning, fall prevention, and safety strategies. We referred subjects identified as at a risk for falls to appropriate providers and made specific recommendations for altered strategies to enhance balance and mobility based on findings, including use of supportive devices such as walkers. Subsequent follow up calls made during the next six months allowed for ongoing discussion of balance, falls and strategies. During each monthly call, subjects who described loss of balance with or without falls were asked about each incidence specifically. This offered an opportunity for researchers to provide feedback regarding efficacy of self - selected strategies. As a result of this monthly dialog, a pattern of behavior became discernable, and through discussion, several subjects became willing to seek additional assistance as originally advised. With our small pilot study, we identified four themes which may be beneficial for body work practitioners caring for visually impaired individuals. These themes include: 1) the need to assess multiple factors underlying fall risk, 2) initial resistance to behavioral change, 3) positive response to ongoing education when provided with specific feedback regarding vision function, and 4) need for visual compensatory strategies to improve mobility. Rehabilitation of the musculoskeletal system dysfunction often involves ongoing care that allows a close bond between the patient and provider. This ongoing contact can be used to assess behavior, and counsel when behaviors are not effective is recommended. People with new onset of visual impairment may be at higher risk for associated health risks including inactivity, obesity and falls. Referral to a professional with skills and training specific for VI strategies is indicated due
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to unique needs for training and adjustment. In the United States these professions include those occupational therapists and optometrists who have specialized training and clinical expertise in working with people with visual impairments. In addition, there are professionals trained specifically to work only with people with visual impairments, such as orientation and mobility specialists who train individuals on safe travel throughout the community.
Conclusion All professions that incorporate body movement should be aware of potential mobility issues in patients with a visual impairment. Professionals may need to alter treatment or instructions for this population. Fall risk evaluation should be performed on people with a visual impairment, either by an appropriately trained optician or by referral to an appropriate mobility specialist who is experienced in working with this population. Best practice requires coordinated, multidisciplinary care for those individuals at high risk of falling. Fall risk intervention across the lifespan is ideal for people with visual impairment to reduce injury and maximize quality of life. Further research in this area is important. Baseline normative measures must be established for this population and further investigation is needed to provide more evidence that time with visual impairment is a predictor of prospective falls, as well as to identify other predictors of falls in adults with visual impairment. We recommend an interdisciplinary approach to studying and managing fall risk in this population.
Financial support None.
Conflicts of interest None.
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6 Kulmala, J., Era, P., Pa ¨rssinen, O., Sakari, R., Sipila ¨, S., Rantanen, T., Heikkinen, E., 2008. Lowered vision as a risk factor for injurious accidents in older people. Aging Clin. Exp. Res. 20, 25e30, 2. Laitinen, A., Sainio, P., Koskinen, S., Rudanko, S.L., Laatikainen, L., Aromaa, A., 2007. The association between visual acuity and functional limitations:findings from a nationally representative population survey. Ophthalmic Epidemiol. 14 (6), 333e342. Lajoie, Y., Gallagher, S.P., 2004. Predicting falls within the elderly community: comparison of postural sway, reaction time, the Berg balance scale and the Activities-specific Balance Confidence (ABC) scale for comparing fallers and non-fallers. Arch. Gerontol. Geriatr. 38 (1), 11e26. Leissner, J., Coenen, M., Froehlich, S., Loyola, D., Cieza, A., 2014. What explains health in persons with visual impairment? Health Qual. Life Outcomes 12, 65. Lord, S.R., Dayhew, J., 2001. Visual risk factors for falls in older people. J. Am. Geriatr. Soc. 49, 508e515. Mangione, C.M., Lee, P.P., Gutierrez, P.R., Spritzer, K., Berry, S., Hays, R.D., 2001. Development of the 25-item national eye Institute visual function questionnaire. Arch. Ophthalmol. 119 (7), 1050e1058. Meyers, A.M., Fletcher, P.C., Myers, A.H., Sherk, W., 1998. Discriminative and evaluative properties of the Activitiesspecific Balance Confidence (ABC) scale. J. Gerontol. A Biol. Sci. Med. Sci. 53, M287eM294. Napier-Dovorany, K., Graham, V., 2013. Evaluating fall risk in people with low vision: a case series. Optom. Vis. Perf. 1 (3), 158e170.
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