Occupational therapists' perspectives on binocular ... - IOS Press

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NeuroRehabilitation 42 (2018) 223–233 DOI:10.3233/NRE-172263 IOS Press

Occupational therapists’ perspectives on binocular diplopia in neurorehabilitation: A national survey Gillian Burgessa,b,∗ and Vanessa D. Jewellc a University

of California, San Francisco Medical Center, San Francisco, CA, USA of Pharmacy and Health Professions, Creighton University, Omaha, NE, USA c Assistant Professor and Director of the Post-Professional Doctorate of Occupational Therapy Program, Creighton University, Omaha, NE, USA b School

Abstract. BACKGROUND: Oculomotor dysfunction affects a significant number of adults with neurological conditions and binocular diplopia is a common symptom which impacts an individual’s ability to participate in meaningful daily activities. Occupational therapists use partial and complete occlusion to minimize binocular diplopia, however a review of the literature reflected a lack of standardized protocol for each intervention technique. The purpose of this study was to examine occupational therapists’ perspectives on the use of partial and complete occlusion and the clinical reasoning process used. METHODS: An electronic survey was distributed to occupational therapists working in a variety of practice settings. The survey contained questions relating to demographics, the selected occlusion technique, and clinical reasoning for that selection. RESULTS: More than half of the 106 respondents used partial occlusion more frequently than complete occlusion. There was no correlation between respondent experience and self-report of competence in managing binocular diplopia. Respondents based their clinical reasoning on available evidence, client factors, and clinical expertise. CONCLUSION: Respondents offered conflicting perspectives on each occlusion technique. Future studies are required to examine which occlusion technique benefits clients. Keywords: Brain injury, clinical reasoning, complete occlusion, low vision, neurorehabilitation, partial occlusion

1. Literature review Acquired brain injury (ABI), which includes cerebrovascular accidents (CVA) or stroke, and traumatic brain injury (TBI), affects over 10 million people globally every year (Hyder, Wunderlich, Puvanachandra, Gururaj, & Kobusingye, 2007). Visual impairment is frequently associated with ABI and oculomotor dysfunction is the most common ∗ Address for correspondence: Gillian Burgess, 2500 California Plaza, Omaha, NE 68178, USA. Tel.: +1 478 227 3896; E-mail: [email protected].

presentation of visual impairment in these individuals (Ciuffreda et al., 2008). Oculomotor dysfunction occurs when the eyes do not work together to fixate on an object, to move from one object to the next, or to follow a moving object (Warren, 2011). Oculomotor dysfunction affects up to 54% of adults with CVA alone, not including TBI, reflecting its significant impact on people with ABI (Rowe, 2011). In addition to ABI, oculomotor dysfunction can occur as a result of a disease process, examples being Parkinson’s disease, multiple sclerosis, tumor resection, brain cancer, myasthenia gravis, and encephalitis (Rosenfield, 2011). Cockerham and colleagues (2009) noted

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G. Burgess and V.D. Jewell / Perspectives on binocular diplopia

that a frequently reported symptom of oculomotor dysfunction is binocular diplopia, or double vision. Binocular diplopia (BD) is a visual deficit resulting from ocular misalignment where the individual perceives two images; the image stimulates the fovea of one eye and the non-foveal region of the other eye (Greenwald, Kapoor, & Singh, 2012; Scheiman, Scheiman, & Whittaker, 2007). If ocular alignment is not achieved, the individual perceives a distorted or duplicate image. Phillips (2007) stated that an individual with BD will usually find relief when the input from one eye is blocked through occlusion, thereby removing the duplicate image. A person with BD may experience balance deficits, visual fatigue, and headaches (Garcia-Munoz, Carbonell-Bonete, & Cacho-Martinez, 2014). Consequently, BD can lead to decreased participation in activities of daily living (ADLs) and instrumental activities of daily living (IADLs) including reading, ambulation, driving, engaging in leisure pursuits, education, and work, which can have a significant effect on an individual’s function (Rowe et al., 2008). These aspects of daily life are the focus of occupational therapy, where the client’s ability to engage in occupation is at the core of the profession (American Occupational Therapy Association [AOTA], 2014). Occupational therapists and occupational therapy assistants working in acute care hospitals, inpatient rehabilitation facilities, skilled nursing facilities, home health, and other community settings may encounter adults with BD. In some cases, these clinicians may be the first healthcare professionals with whom clients with BD may interact, especially in more rural communities (Scheiman et al., 2007). Fortunately, BD can be managed through occlusion of either eye and Politzer (1996) suggested that either partial or complete occlusion interventions can be used to temporarily resolve BD.

1.1. Partial occlusion Partial occlusion is an intervention technique where the clinician places lightly opaque tape over a portion of one lens of a pair of glasses. This occludes just the portion of the visual field where the individual perceives diplopia, leaving the remainder of the visual field unobstructed (Politzer, 1996; Warren, 2005). This intervention allows the individual to achieve single vision while keeping both eyes open, which is the primary goal in treating BD (Greenwald et al., 2012).

Although there is evidence in the literature to support the use of partial occlusion to manage BD (Houston & Barrett, 2017; Politzer, 1996; Rucker & Tomsack, 2005; Warren, 2011), there is a paucity of research available examining the efficacy of partial occlusion over no intervention in the acute stage after onset of disease or trauma. Riggs, Andrews, Roberts, and Gilewski (2007) completed a systematic review investigating effective interventions for visual impairment after stroke or brain injury and found limited evidence supporting effective interventions for resolving BD. The authors cited one study indicating that partial occlusion correlated with an improvement on the Functional Independence Measure (Beis, Andre, Baumgarten, & Challier, 1990, as cited in Riggs et al., 2007), an outcome measure commonly used in acute rehabilitation facilities to quantify a person’s performance in self-care, cognition, and functional mobility (Keith, Granger, Hamilton, & Sherwin, 1987). Similarly, partial occlusion has been found to be an effective intervention for managing BD without the introduction of additional deficits that could result from closing one eye (Phillips, 2007; Politzer, 1996; Warren, 2011). These additional deficits can include loss of peripheral awareness, stereopsis or depth perception, and balance. 1.2. Complete occlusion Complete occlusion involves placing an eye patch over the entire eye to remove the duplicate image. This intervention technique is more commonly used as it is often considered the most convenient compensatory strategy (Phillips, 2007). However, complete occlusion introduces additional deficits including loss of peripheral awareness, stereopsis or depth perception, and balance, the most significant of which is the lack of peripheral awareness (Fraine, 2012; Politzer, 1996). Politzer (1996) cited a 25% reduction in the peripheral visual field when complete occlusion is utilized. This reduction in visual field can have a profound effect on the individual’s ability to negotiate his or her environment and can lead to safety concerns (Greenwald et al., 2012). Phillips (2007) echoed the concerns of Politzer cited above, agreeing that complete occlusion eliminates stereopsis and results in the individual’s inability to achieve ocular fusion. More recently, Houston and Barrett (2017) included in this list, the concern for introducing spatial neglect through the use complete occlusion amongst adults with brain injuries. Clinicians should be mindful of potential additional impairments introduced through


selected interventions (Warren, 2011). Moreover, Fraine (2012) reported that complete occlusion is not considered a long-term solution for managing BD, suggesting that a more effective technique should be implemented. 1.3. Role of occupational therapy in managing binocular diplopia An appropriate occlusion intervention can minimize functional impairment and facilitate engagement in daily occupation. Occupational therapists play a key role in identifying functional deficits resulting from oculomotor dysfunction (Rowe et al., 2008; Warren, 2017). It is these clinicians who have the skills to address both sensorimotor and psychosocial sequelae of BD. These clinicians utilize these intervention techniques in their practice to reduce the detrimental effects that BD can have on engagement in meaningful activity. An occupational therapist will typically not treat BD. Instead, an eye care professional will become involved in the long-term management of BD if the deficit persists past the acute stages of disease onset or neurological injury (Warren, 2011). However, since BD can often be temporarily resolved through the occlusion of one eye, Warren (2011) observed that it is the occupational therapist or occupational therapy assistant who, after consulting with the referring physician, can effectively manage BD until the deficit resolves, or until the individual can consult with an eye care professional for more definitive management, which may include the use of prism lenses. 1.4. Problem statement Partial and complete occlusion are two compensatory strategies that occupational therapists can utilize in the management of clients with BD, regardless of the clinician’s practice setting. Current literature presents both benefits to, and disadvantages of, the two types of occlusion and their impact on an individual’s functional performance. Nevertheless, there are no uniform guidelines for clinicians on the use of partial or complete occlusion. Furthermore, as indicated in the study by Riggs and colleagues (2007), there is insufficient evidence to identify which of the two intervention techniques is more effective in managing BD. Despite having knowledge regarding occlusion, clinicians cannot agree on the reasoning behind the choice of intervention, and there is no evidence

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to indicate which intervention is more beneficial to the client. This presents a challenge to occupational therapists who have been urged to integrate the best available evidence together with their own clinical expertise and client values in making clinical decisions (Sackett, Rosenberg, Gray, Haynes, & Richardson, 1996). To generate much-needed evidence, it is useful to establish which intervention technique occupational therapists are utilizing in their current areas of practice and to determine the factors that influence clinical decision-making across the rehabilitation continuum. This information can both guide clinicians in practice and set a baseline for future effectiveness studies, and serve as an aid to the development of occupational therapy education curricula. 1.5. Purpose statement and research questions The purpose of this study was to explore current practice regarding the use of partial or complete occlusion and to investigate the clinical reasoning occupational therapists utilize in determining whether to use partial or complete occlusion. The research questions addressed in this study relate to clinical practice and clinical reasoning respectively: 1) Do occupational therapists in acute care hospitals, acute rehabilitation facilities, skilled nursing facilities, home health, and other community settings tend to use partial occlusion or complete occlusion in the management of adults with binocular diplopia? 2) What factors guide occupational therapists in their clinical reasoning to determine whether to use partial or complete occlusion in managing adult clients with binocular diplopia?

2. Methods 2.1. Research design This was a cross-sectional survey design. This design satisfied the requirements of an overarching descriptive study as the data described the current practice of a population of clinicians (Portney & Watkins, 2015). In this study, the phenomenon under investigation was the current practice by occupational therapists in managing BD. The survey included both closed- and open-ended questions. Responses to closed-ended questions are often easier for the

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researcher to collect and analyze (O’Cathain & Thomas, 2004); however, more detailed information can often be collected through open-ended questions (Portney & Watkins, 2015).

open-ended question, respondents were invited to make any additional comments regarding the study.

2.2. Participants

The university’s Institutional Review Board approved the study. Respondents provided informed consent through voluntary submission of their responses. The researchers used non-probability purposive sampling to increase the likelihood that potential respondents have some knowledge regarding the interventions (Portney & Watkins, 2015). The primary researcher recruited respondents through direct emailing of the survey link, via online discussion boards for professional occupational therapy practice communities, and on appropriate social media platforms. The primary researcher used snowball sampling to further increase the sample size by inviting recipients of the emailed survey link to forward the link to clinicians in their professional networks. The primary researcher posted an explanation of the research study with the survey link to the American Occupational Therapy Association’s online community forums on OTConnections (AOTA, 2017a) and on four occupational therapy-related public groups on Facebook. In addition, the primary researcher sent an email announcement letter, with a link to the survey, to 160 occupational therapists, students, and faculty known to her. The primary researcher was responsible for posting reminders to increase the sample size, posting two reminders to each of the online discussion boards. Because of anonymity of respondents, those recruited via email did not receive reminders. The survey was available for a period of 10 weeks before closing.

2.2.1. Inclusion and exclusion criteria Full-time and part-time occupational therapists and occupational therapy assistants were eligible to participate. Clinicians in any practice setting and with any number of years of clinical experience met the inclusion criteria. Clinicians with no experience with BD were excluded from completing the survey, as were those who did not work with adult clients. 2.3. Instrument The researchers completed a thorough review of the literature exploring current practice relating to BD and developed an anonymous online survey to capture clinicians’ perspectives on BD. Web-based surveys may be advantageous over paper surveys for several reasons: anonymity of respondents may be maintained, convenience for the researcher in recording responses directly to a database for analysis, a lower financial burden on the researcher, and a reduced time commitment for the respondents (Eysenbach & Wyatt, 2002; Portney & Watkins, 2015). After the survey was reviewed by an expert panel skilled in research design (n = 5), a sample of five occupational therapists piloted the survey to assess face and content validity. One area modified from the pilot sample was to include a question investigating the respondent’s perception of the client’s benefit in managing BD. This change aligned with the Occupational Therapy Practice Framework, highlighting client-centered care (AOTA, 2014). The final version of the survey consisted of 29 questions. Eight questions sought to obtain demographic data from the respondents. The survey included 10 rating questions, designed to gather data regarding the choice of intervention and clinicians’ perceptions on the use of partial or complete occlusion in managing BD. Each Likert-scale question consisted of the categories strongly agree, somewhat agree, neither agree nor disagree, somewhat disagree, and strongly disagree. Five questions sought data on the type of occlusion used and the frequency with which clinicians used each method. Four open-ended questions concerned the clinicians’ clinical decision making. For the fifth

2.4. Procedure

2.5. Data analysis 2.5.1. Quantitative data The researchers used descriptive statistics, including tables and figures, to describe frequencies and percentages of the characteristics of the respondents and the interventions used in practice. Spearman’s correlational analysis was used to investigate a potential relationship between years of experience and clinician self-report of competence in managing BD. 2.5.2. Narrative data The primary researcher analyzed the narrative data using thematic analysis. Vaismoradi and colleagues


(2013) described thematic analysis as a systematic method of describing narrative data, and determining patterns from respondents concerning a particular topic. In this case, this data was obtained from the open-ended survey questions regarding partial or complete occlusion. Using inductive thematic analysis, patterns emerged from the data. Thematic analysis is helpful to describe a phenomenon when existing research on the topic is limited (Vaismoradi et al., 2013). Peer debriefing was performed when both the primary and second researchers reviewed the elements to ensure trustworthiness. Peer debriefing can be an effective method of ensuring credibility (Graneheim & Lundman, 2004). The researchers maintained an audit trail throughout the process. This included noting the initial emails sent and postings to discussion groups, posting reminders to discussion groups, and closing the survey to begin data analysis.

3. Results The respondents practiced in acute care hospitals, inpatient rehabilitation (sub-acute) facilities, skilled nursing facilities, home health, out-patient clinics, and other community health settings. Of the 130 respondents who opened the survey received via email or posted on professional forums, 23 did not meet inclusion criteria and one did not complete the survey, which reduced the sample size to 106 respondents (105 occupational therapists and one occupational therapy assistant). The researchers were unable to determine the response rate due to the selected recruitment strategies. About half of the respondents worked in acute care hospital settings (48%; n = 52). Forty-two percent of respondents had less than five years’ experience (n = 45), while 27% of respondents had more than 15 years of experience (n = 29). The majority of respondents held a master’s degree (56%; n = 59). Table 1 represents the respondent demographic characteristics. At most, 10 respondents did not complete all the questions, however the researchers chose to include all questions in the analysis to reflect respondent opinion. 3.1. Clinical practice Respondents were asked how frequently they utilized partial occlusion, complete occlusion, other occlusion methods, or no occlusion in managing BD. Partial occlusion and complete occlusion

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Table 1 Respondent demographics (N = 106) Characteristic Practice setting Acute care hospital Sub-acute rehabilitation Skilled nursing facility Home health Out-patient clinic Day treatment program Other Years in practice 0–2 3–5 6–10 11–15 16–20 21+ Employment status Full-time, career staff Part-time, career staff Full-time, contract staff (per diem) Part-time, contract staff (per diem) Highest level of OT education Associate’s Bachelor’s Master’s Clinical doctorate (OTD) Research doctorate (PhD) Specialties or certifications held None Low vision Stroke Neuro Brain injury Certified driver rehabilitation Other Client populations treated Stroke Acquired brain injury Traumatic brain injury Neurodegenerative disorders Brain tumors Neuro vision deficits Other Clients with diplopia per month 1–5 6–10 11–15 16 or more

na

%b

52 40 5 3 23 4 5

48.6 37.38 4.67 2.8 21.5 3.74 4.67

21 24 24 9 16 14

19.63 22.43 22.43 8.41 14.95 12.15

85 12 3 6

80.19 11.32 2.83 5.66

1 29 59 15 1

0.95 27.62 56.19 14.29 0.95

61 2 3 16 11 2 18

59.22 1.94 2.91 15.53 10.68 1.94 17.48

105 96 94 85 89 79 13

99.06 90.57 88.68 80.16 83.96 74.53 12.26

93 10 2 1

87.74 9.43 1.89 0.94

Note. a Frequencies obtained from the number of respondents who responded for each question. b Some percentages may exceed 100% as survey respondents were able to select more than one response.

were most frequently utilized. Table 2 represents the frequency of occlusion techniques used. Other methods included the use of prism lenses, oculomotor and visual scanning exercises, Brock string, DynavisionTM , and Interactive Metronome® . Respondents who did not use an occlusion method allowed clients to close one eye to resolve BD.

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G. Burgess and V.D. Jewell / Perspectives on binocular diplopia Table 2 Frequency of occlusion technique Question

Always

Most of the time

Half the time

Some of the time

Never

n

15- Partial occlusion 18- Complete occlusion 21- Other occlusion methods 22- No occlusion

15.24% 2.02% 6.25% 2.13%

35.24% 13.13% 6.25% 6.38%

14.29% 8.08% 10.42% 11.70%

25.71% 48.48% 43.75% 63.83%

9.52% 28.28% 33.33% 15.96%

105 99 96 94

Fig. 1. Respondent feedback from Likert-scale questions on clinical practice in the use of occlusion.

3.2. Clinical reasoning Over half the respondents indicated they held no additional specialty certification (59%; n = 61). Only two respondents held low vision specialty certifications. Spearman tests of correlation between years of clinical experience and respondent report of competence in managing BD yielded results of rs = 0.23 (p < 0.0005). Following the demographic questions, respondents were asked to complete Likert-scale questions by selecting one of the following responses for each question: strongly agree, somewhat agree, neither agree nor disagree, somewhat disagree, or strongly disagree. Ninety-six percent of respondents (n = 103) agreed that clients with BD have more difficulty performing ADLs than those without visual impairment (strongly agree 77%; somewhat agree 19%). Ninety-seven percent of respondents (n = 95) agreed that clients were better able to participate in ADLs when BD was managed (strongly agree 85%; somewhat agree 12%). Ninety-three percent of respondents (n = 99) agreed that occupational therapists and occupational therapy assistants should be able to manage BD in their practice setting (strongly agree 63%; somewhat agree 30%). Fewer than 80% of respondents (n = 85) reported feeling competent in managing these clients (strongly agree 22%; somewhat agree 57%). Only 38% of

respondents (n = 37) agreed that there was sufficient evidence in the literature regarding the use of partial and complete occlusion (strongly agree 6%; somewhat agree 32%). Sixty-two percent of respondents (n = 67) reported that clinicians should consult with a neuro-optometrist or ophthalmologist before using partial or complete occlusion (strongly agree 27%; somewhat agree 35%). The majority of respondents (55%; n = 59) indicated that they did not have access to neuro-optometry or ophthalmology services at their facilities (question 13). Ninety-six respondents answered the questions “It does not make a difference how I occlude, as long as the diplopia is resolved” (question 24); “I always use the same occlusion technique for all my clients with BD” (question 25); and “I vary my occlusion technique based on the needs of my clients” (question 26). Most respondents disagreed with questions 24 and 25, while most agreed with question 26. Figure 1 represents the respondents’ answers. Additional survey questions investigated the clinical reasoning respondents used in their selection of occlusion technique. The four open-ended questions relating to clinical reasoning were coded by the primary researcher and elements were allowed to emerge from the data. The respondents’ answers covered two main elements: clinical decisions taken from the client’s perspective and clinical decisions from the clinician’s perspective.


3.2.1. Clinical indication for partial occlusion (question 16) This question (n = 54) required those respondents who used partial occlusion more than 50% of the time to provide a clinical example of when they might select this method over other methods. Respondents cited client comfort and tolerance for partial occlusion, symptom alleviation, client safety, remediation versus compensation, and sensory input and sensory stimulation as factors in their clinical reasoning.

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of occupational therapy in managing BD. Twentynine respondents answered this question. The main findings that emerged from these responses included the need for additional education and training on occlusion techniques, the need for occupational therapists to collaborate with an eye care professional, and a lack of evidence regarding the use of partial or complete occlusion.

4. Discussion 3.2.2. Indication for not using partial occlusion (question 17) Respondents (n = 81) cited education of clinicians, patients/families, medical teams, and nursing staff as well as lack of consultation with neuro-optometry as factors in the decision not to use partial occlusion. Respondents cited their own lack of knowledge on the topic in 13 of 81 responses (16%). Limitations in terms of time, equipment, and client cognition, and poor client tolerance for partial occlusion were also identified. 3.2.3. Clinical indication for complete occlusion (question 19) This question (n = 16) required respondents who used complete occlusion more than 50% of the time to provide a clinical example of when they might select this method over other methods presented. Respondents identified client comfort and tolerance for complete occlusion, and client cognition. Lack of equipment, limited clinician knowledge, and established physician protocols regarding methods of occlusion used were presented as examples by respondents. 3.2.4. Indications for not using complete occlusion (question 20) Respondents (n = 84) identified education of clinicians, patients/families, medical teams, and nursing staff as factors as well as respondent perceptions of complete occlusion being ineffective, compensatory, and causing a reduction in sensory input. Respondents cited poor client tolerance and compliance, and lack of sufficient evidence for the use of complete occlusion as additional reasons for not using complete occlusion in the management of BD. 3.2.5. Additional comments For the final question of the survey, respondents were invited to offer additional comments on the role

Occupational therapists across a wide variety or practice settings indicated that they treated adult clients who present with BD. The purpose of this survey was to identify whether occupational therapists and occupational therapy assistants used partial or complete occlusion in the management of adult clients with BD and to investigate what factors guide these clinicians in their clinical reasoning when using either of the two occlusion techniques. The overall results of this study indicated that respondents strive to consider not only available evidence, but also their individual clients’ values and preferences in providing an intervention, which aligns with the widely-accepted definition of evidence-based practice from Sackett and colleagues (1996). 4.1. Clinical practice The most commonly reported intervention techniques were partial and complete occlusion, which is consistent with available literature (Houston & Barrett, 2017; Phillips, 2007; Politzer, 1996; Rucker & Tomsack, 2005; Warren, 2011). Both these occlusion techniques remove the duplicate image to temporarily resolve BD, thereby providing some relief to the individual with BD. An expected finding from this study was that respondents agreed that complete occlusion is more convenient. Both Phillips (2007) and Politzer (1996) cited complete occlusion as a simple and effective intervention. Surprisingly, however, despite the convenience of complete occlusion, most respondents indicated they used partial occlusion more than half the time, and used complete occlusion less than half the time. This finding reflects the respondents’ awareness of the concerns, including the loss of depth perception, peripheral awareness, and balance, cited by experts Fraine (2012), Phillips (2007), Politzer (1996), and Warren (2011) when complete occlusion is used. It was difficult to obtain the true frequency with which respondents used each

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occlusion technique due to the nature of the Likert questions containing a wide range of frequency representations for each occlusion technique used: for example, the range between Always at 100% and Most of the Time at 75% is broad. 4.2. Clinical reasoning Almost all respondents agreed that BD affects an individual’s function, that function improves when BD is addressed, and that occupational therapists should be able to manage BD in their practice settings. Nevertheless, fewer respondents who reported agreement with these statements felt competent in managing BD with these clients. This incongruence speaks to a decreased awareness of the role of occupational therapy in low vision rehabilitation and supports the need for more education in low vision rehabilitation to be included in occupational therapy program curricula. Furthermore, the surprising absence of a correlation between years of clinician experience and self-report of competence in addressing BD, as evidenced by the strong negative Spearman’s rank correlation, suggests that newer occupational therapy graduates are no better equipped with the latest knowledge in low vision rehabilitation than their more experienced colleagues. As an expert in low vision rehabilitation, Warren (2017) stressed the fact that occupational therapists are ideal healthcare professionals to address visual impairments because of their solid foundation in neuro-anatomy, neuroscience, and chronic disease. Clinician expertise is a crucial component of evidence-based practice and clinicians need to be able to assimilate knowledge with evidence. In contrast to the findings of Rowe and colleagues (2008) that occupational therapy plays a key role in managing BD, there were two respondents who did not agree that this was within the scope of practice for occupational therapists and occupational therapy assistants, and five respondents who neither agreed nor disagreed. This unexpected finding contradicts the efforts of the AOTA, led by Warren, in developing a specialty certification for low vision rehabilitation to promote competence in this area (AOTA, 2017b). An incidental finding was that only two respondents held this specialty certification. Occupational therapists are tasked within the Occupational Therapy Practice Framework (AOTA, 2014) to consider all client factors, including visual functions, that may impact the client’s ability to engage in meaningful occupation. Moreover, occupational therapists have a

unique understanding of the interaction between the individual and his/her environment (AOTA, 2014). Promoting low vision rehabilitation in occupational therapy curricula would help eliminate misconceptions regarding the role of occupational therapy in low vision rehabilitation such as those expressed by the seven respondents above. Similarly, the respondents’ perception of the lack of evidence surrounding the use of partial and complete occlusion is a cause for concern as it reflects a disconnect between clinical practice and the Patient Protection and Affordable Care Act of 2010 ([ACA]; Pub L. 111-148) in which clinicians are urged to implement interventions that are based on evidence. However, since Riggs et al. (2007) were also unable to find sufficient evidence supporting effective interventions for managing BD, the respondents’ perceptions are valid. Furthermore, respondents cited sound reasoning for their choices of occlusion intervention technique, reflecting their commitment to following the guidelines of evidence-based practice as identified by Sackett and colleagues (1996) to incorporate clinician experience with the best available evidence. The limited evidence in the literature supports the use of partial over complete occlusion (Fraine, 2012; Politzer, 1996; Riggs et al, 2007). Politzer (1996) cited concerns regarding the use of complete occlusion, including potential loss of visual field, peripheral vision deficits, and concerns for safety and loss of depth awareness. Several of these same concerns were reported by the respondents who cited client safety; improved participation in ADLs and IADLs; client tolerance and comfort; and clinician concerns for introducing additional sensory, perceptual and visual-spatial deficits as indications for using partial occlusion. Those who tended to use complete occlusion cited a lack of knowledge regarding partial occlusion; improved client tolerance for the patch rather than taped glasses; limited time and equipment; and operating under the orders of a physiciandirected standardized protocol that promotes the use of complete occlusion. This seemingly contradictory reasoning provided by respondents does, however, reflect that the respondents consider the clients’ perspectives in providing care. This aligns with both the Occupational Therapy Practice Framework and the Triple Aim of the ACA, where interventions provided should be of value to the client (AOTA, 2014; Berwick, Nolan, & Whittington, 2008). To further indicate respondents’ consideration for each individual client, an overwhelming 88% of respondents reported that they vary the occlusion


technique based on the client’s needs. While it would be expected that all occupational therapy clinicians would modify the intervention for the client, in this case, many respondents indicated that they operated under a standardized protocol from a physician which may limit the intervention options. This finding supports the need for more evidence regarding the value of occupational therapy in this clinical arena. It also highlights the need for collaboration with eye care professionals. Many respondents did seek the assistance of an eye care professional to gain additional education in the use of occlusion techniques. A consistent finding was that respondents collaborated with an optometrist or neuro-ophthalmologist before implementing an occlusion intervention technique and referred their clients for follow up. Clinicians should be encouraged to foster these inter-professional relationships to best meet their clients’ needs (Warren, 2011). This applies particularly to clinicians who practice in postacute care settings, where clients with chronic BD may require consultation from an eye care professional for definitive treatment, including the use of prism lenses. In these cases, occupational therapists should remain involved in the client’s care to continue to assess the client’s needs in all aspects of participation (Warren, 2017).

4.3. Limitations and future research There are several limitations related to data collection. First, the survey was self-developed and only content and face validity were established. Second, the survey targeted clinicians who are members of professional online communities which may not be representative of all clinicians who use partial or complete occlusion. This limitation is inherent in purposive sampling (Portney & Watkins, 2015). Third, the small sample size lessens the ability for the generalization of findings to a larger population (Portney & Watkins, 2015). Fourth, the 5-point Likert-scale questions gave respondents the option of selecting a neutral response and did not compel the respondents to select a level of agreement or disagreement with a particular statement (Dolnicar, Grun, Leisch, & Rossiter, 2014). Finally, due to the anonymity of the study, member checking was not completed after analyzing the open-ended questions. However, to offset the limitations, the researchers used peer debriefing as one collaborative method of triangulation, which can enhance credibility (Anderson, 2010).

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There was much variety in the responses from clinicians regarding the use of partial and complete occlusion. This diversity in clinical practice reflects a need for standardization to establish uniformity amongst clinicians to best meet the needs of their clients. Several options should be considered to direct future research and guide practice. One, clinicians should be encouraged to publish case studies for the different occlusion techniques. While this type of evidence is considered lower level evidence, Niederman, Clarkson, and Richards (2011) suggested that when stronger evidence is not available, clinicians can consider interventions based on their experience. This suggestion reflects the guidelines from Sackett and colleagues (1996) regarding the three components of evidence-based practice: evidence, clinician expertise, and client values. Two, clinicians should conduct future research studies looking at the use of both partial and complete occlusion in occupation-based assessments. This would allow clinicians to further examine the functional implications to the client and explore which occlusion intervention results in more positive outcomes for the client. This type of study will facilitate the development of practice guidelines for the treatment of BD in adults. Finally, respondents cited lack of education and training regarding the two occlusion techniques as barriers to utilizing them in practice. The results of this study may inform the development of education curricula to emphasize low vision rehabilitation both in the occupational therapy classroom and in fieldwork education experiences.

5. Conclusion Binocular diplopia affects many individuals with acquired brain injury or neurological disease and impacts their ability to engage in meaningful occupation. Occupational therapists are uniquely skilled at recognizing and addressing barriers to participation. The researchers developed a custom survey to collect data on occupational therapy clinicians’ perspectives on the use of partial and complete occlusion in adult clients with BD. Most respondents indicated that they used partial occlusion over complete occlusion, but reported a lack of competence in managing BD. Despite this self-reported lack of competence, respondents tended to base their clinical decisions on the limited evidence from the literature. Furthermore, respondents outlined contrasting clinical applications from their own experiences in the use of both partial and complete occlusion and articulated sound

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clinical reasoning for selecting an intervention technique for a particular client. The findings from this study indicated that respondents are attempting to integrate the three components of evidence-based practice suggested by Sackett et al. (1996): “individual clinical expertise . . . the best available evidence . . . individual patient preferences” (p. 71). However, with the resulting conflicting perspectives, it is crucial for future researchers to explore the functional implications for selecting partial or complete occlusion to drive evidence-based practice and to provide standardized clinical indications for each occlusion intervention technique.

Acknowledgments The authors would like to acknowledge Dr. Kathleen Flecky, Associate Professor at Creighton University, for her guidance in the research proposal. Conﬂict of interest The authors have no conflicts of interest to declare. This research study was completed in partial fulfilment of the Creighton University’s post-professional occupational therapy doctoral degree. References American Occupational Therapy Association. (2014). Occupational therapy practice framework: Domain and process (3rd ed.). American Journal of Occupational Therapy, 68, S1-S48. American Occupational Therapy Association. (2017a). OTConnections. Retrieved from https://otconnections.aota.org/ American Occupational Therapy Association. (2017b). Specialty certification in low vision. Retrieved from http://www.aota.org/ Education-Careers/Advance-Career/Board-Specialty-Certific ations/Low-vision.aspx Anderson, C. (2010). Presenting and evaluating qualitative research. American Journal of Pharmaceutical Education, 74, 141. Berwick, D. M., Nolan, T. W., & Whittington, J. (2008). The Triple Aim: Care, health, and cost. Health Affairs, 27, 759-769. Ciuffreda, K. J., Rutner, D., Kapoor, N., Suchoff, I. B., Craig, S., & Han, M. E. (2008). Vision therapy for oculomotor dysfunctions in acquired brain injury: A retrospective analysis. Optometry, 79, 18-22. Cockerham, G. C., Goodrich, G. L., Weichel, E. D., Orcutt, J. C., Rizzo, J. F., Bower, K. S., & Schuchard, R. A. (2009). Eye and visual function in traumatic brain injury. Journal of Rehabilitation Research and Development, 46, 811-818.

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