Abstract
Refractive ametropia has a high prevalence in people with intellectual disabilities. It has a significant impact on their quality of life. Although glasses counteract the visual impairment caused by refractive ametropia, wearing glasses is still uncommon for people with intellectual disabilities, and getting used to wearing glasses can be challenging. In addition, the client’s support system often believes that the effort of learning to wear glasses does not outweigh the benefits. The literature lacks evidence-based interventions and information on the effects of wearing glasses. This comment article aims to discuss the difficulties and opportunities for researching the impact of wearing glasses to correct refractive ametropia in people with a profound to moderate intellectual disability.
Visual impairment has a significant impact on daily functioning and quality of life for people with intellectual disabilities (IDs). There is a high prevalence of refractive ametropia for people with IDs (Van Isterdael et al., 2008), which – when untreated – can lead to a visual impairment. Moreover, people with IDs are limited in their ability to counterbalance this visual impairment (De Wit et al., 2019), resulting in difficulties with a vision-related behaviour, such as eye-hand coordination and communication skills. Hence, these vision-related behaviours may then require more effort and can enhance stress, which in turn could lead to a challenging behaviour (Dijkhuizen et al., 2016; De Winter et al., 2011).
Glasses are a common aid that can correct refractive ametropia and reduce or remove the visual impairment. However, people with IDs and refractive ametropia often do not wear glasses (Van Splunder et al., 2003, 2004). The leading cause of not wearing glasses is that professionals do not acknowledge refractive ametropia and do not prescribe glasses (Li et al., 2015). When glasses are prescribed, getting used to wearing glasses can be an additional challenge for people with IDs. Habituation to wearing glasses is often slow, requiring a structured approach and support from parents and caregivers to overcome resistance. It can take months for the benefits of wearing glasses to become apparent, especially for people with severe ID who cannot verbalise what wearing glasses means to them.
Due to these challenges, the client’s support system does not always consider reducing visual impairment as a benefit and/or believes the benefits of wearing glasses do not outweigh the effort of learning to wear glasses. Parents and caregivers assess the chances of successfully wearing glasses as low, doubt that glasses will positively affect the behaviour and functioning of their child/client, and as a result, may be apprehensive about using prescription glasses. This reluctance from the client’s support system increases as the disabilities become more complex and severe (Li et al., 2015).
Since wearing glasses is expected to contribute to enhancing the functioning of persons with profound to moderate ID and to improve their quality of life, the authors of this comment article aimed to conduct a randomised multiple baseline study to determine the effects of wearing glasses for persons with profound, severe, or moderate IDs. The study consisted of video-recorded interaction moments between caregivers and participants with profound to moderate IDs, questionnaires filled out by the caregivers, and semi-structured interviews with caregivers and legal guardians. However, the study was not viable as we aimed to include 12 participants, and despite many efforts, only two participants could be included, one of whom dropped out. Our contact persons who recruited the participants reported two reasons for the low response. First, caregivers and legal guardians mentioned the impact or strain of the number of video recordings (N = 19) on the client and the system. Due to the expected challenges of learning to wear glasses, caregivers anticipated resistance from the client. They carefully protected their clients from additional effort and challenges from participating in this study. Second, the care organisations where we recruited participants struggled with staff shortages, which caused challenges in organising basic care, let alone facilitating participation in research.
Literature on the topic of refractive ametropia for people with ID has focused on prevalence (Van Den Broek et al., 2006), type of visual impairment (Chen et al., 2023), problems associated with visual impairments (De Winter et al., 2011), feasibility of type of glasses (e.g., bifocal glasses; De Weger et al., 2020), prescription of glasses (Nipe et al., 2018), and the effect of glasses for other target groups (e.g., elderly, Teresi et al., 2003; or children, Paysse et al., 2022). However, the literature lacks studies on the effects of wearing glasses for adults with profound to moderate ID. These studied target groups (e.g., elderly, children) have little comparability with persons with IDs. Therefore, feasible study designs for their target group may not be viable for studies including adults with profound to moderate IDs, for example, only using questionnaires for their measurements, which might not capture subtle or more minor changes.
We wrote this comment article to raise awareness of the importance, challenges, and opportunities regarding studying the effects of wearing glasses for this target group. We would like to conclude this article with some of our insights and thoughts on making this research viable in the future. First, we consider international collaborations. Even though researchers from one country might have too few participants for scientific validity, combining studies from multiple countries may result in more participants, generalisable results, and maybe even additional information on social and cultural influences on the perception towards habituation to wearing glasses. Second, to avoid disrupting participants with profound to moderate ID daily schedules, we consider requesting caregivers to make the video recordings themselves. However, this change requires more effort from the caregivers and clear instructions from the researchers on what and how to record. Finally, we reflect on the design of our study and recommend a design with fewer video recordings to minimise the load on participants while still maintaining scientific integrity. Especially for international collaborations, it may be possible to change the design to a randomised control trial with only two or three measurements over a large group of participants. Alternatively, the design could be altered to a qualitative research design that includes semi-structured interviews with professionals, caregivers, family, and, where possible, people with ID to gather different perspectives and tacit knowledge from all stakeholders on the effects of wearing glasses for people with IDs.
