Vision loss has a significant impact on the lives of those who experience it as well as on their families, their friends, and society. The complete loss or the deterioration of existing eyesight can feel frightening and overwhelming, leaving those affected to wonder about their ability to maintain their independence, pay for needed medical care, retain employment, and provide for themselves and their families. The health consequences associated with vision loss extend well beyond the eye and visual system. Vision loss can affect one’s quality of life (QOL), independence, and mobility and has been linked to falls, injury, and worsened status in domains spanning mental health, cognition, social function, employment, and educational attainment. Although confounding factors likely contribute to some of the harms that have been associated with vision impairment, testimony from visually impaired persons speaks to the significant role that vision plays in health, vocation, and social well-being.
The economic impact of vision loss is also substantial. One national study commissioned by Prevent Blindness found that direct medical expenses, other direct expenses, loss of productivity, and other indirect costs for visual disorders across all age groups were approximately $139 billion in 2013 dollars (Wittenborn and Rein, 2013), with direct costs for the under-40 population reaching $14.5 billion dollars (Wittenborn et al., 2013). These costs affect not only national health care expenditures, but also related expenses and the resources of individuals and their families. For example, Köberlein and colleagues (2013) found that the time spent by caregivers increases substantially as vision decreases.
This chapter explores the impact of chronic vision loss in the United States—both in terms of its financial costs and its effects on QOL. The first two sections of the chapter details the consequences of vision impairment and the relationship between chronic vision impairment and other chronic conditions. The third section of this chapter provides an overview of the economic impact of vision loss on individuals, insurers, and society, including estimates of direct and indirect costs, and life years lost. The final section discusses the state of cost-effectiveness research for clinical eye and vision care.
Quality of Life
Vision impairment is associated with a reduced QOL, which is a “complex trait that encompasses vision functioning, symptoms, emotional well-being, social relationships, concerns, and convenience as they are affected by vision” (Lamoureux and Pesudovs, 2011, p. 195). Numerous studies have shown that vision impairment is often associated with various negative health outcomes and poor QOL (Chia et al., 2006; Langelaan et al., 2007). A recent study using Behavioral Risk Factor Surveillance System (BRFSS) data from 22 states examined unadjusted health-related QOL among individuals ages 40 to 64 years by visual impairment status and found that the percentage of individuals reporting life dissatisfaction, fair or poor reported health, physical and mental unhealthy days, and days of limited activity increased as the self-reported severity of vision impairment increased (Crews et al., 2016b) (see Table 3-1). An earlier study found similar results among people ages 65 and older (Crews et al., 2014). Based on a variety of measurement instruments, reduced QOL has been related to the severity of disease in glaucoma, cataract, age-related macular degeneration, and strabismus (Chai et al., 2009; Chatziralli et al., 2012; Cheng et al., 2015; Freedman et al., 2014; Hassell et al., 2006; Orta et al., 2015). Although greater emphasis is traditionally placed on the better-seeing eye’s role in visual function, one study concluded that the worse-seeing eye contributes importantly to patients’ estimates of vision-related QOL, particularly when the underlying eye disease affects peripheral vision (e.g., in the case of glaucoma) (Hirneiss, 2014).
A study by Rein and colleagues (2007) found that the QOL begins to slowly decline with the onset of vision loss, and then decreases more precipitously as measures of visual field defects increase. A systematic literature review of studies that reported QOL in patients with central vision loss or peripheral vision loss, and found that both types of vision loss were associated with similar degrees of detriment to QOL, although “different
TABLE 3-1 Unadjusted Health-Related Quality of Life Among Those Ages 40 to 60 by Visual Impairment Status in 22 States,a 2006 to 2010, United States
|Health-Related Quality of Life Measure||n||Total % (95% CI)||No Difficulty Seeing % (95% CI)||Little Difficulty Seeing % (95% CI)||Moderate/Severe Difficulty Seeing % (95% CI)|
|Life dissatisfaction (yes)||6,915||5.8||3.7||6.0||13.3|
|Self-reported health (fair/poor)||19,182||17.1||12.4||17.8||33.0|
|14 to 30 physical unhealthy days||14,196||12.4||9.2||12.7||23.7|
|14 to 30 mental unhealthy days||12,386||11.0||7.7||11.7||21.7|
|14 to 30 activity limitation days||9,571||8.2||5.5||8.5||17.8|
NOTES: a The 22 states using the BRFSS vision module at least once in the years 2006–2010 were Alabama, Arizona, Arkansas, Colorado, Connecticut, Florida, Georgia, Indiana, Iowa, Kansas, Maryland, Massachusetts, Missouri, Nebraska, New Mexico, New York, North Carolina, Ohio, Tennessee, Texas, West Virginia, and Wyoming.
CI = confidence interval.
SOURCE: Crews et al., 2016b.
domains were affected” which “might be a function of the pathology of diseases” (Evans et al., 2009, p. 433). A recent Korean study, using the EQ-5D instrument1 examined QOL scores based on whether participants were visually impaired2 and whether they had 1 of 14 chronic conditions. The authors found that QOL scores in persons with each of the 14 chronic conditions, excepting coronary artery disease, were lower among individuals with that condition alone than individuals who also had any co-existing
1 The EQ-5D is a generic instrument used to measure health-related QOL. The tool rates the impact of disease on a scale of 0 to 1 with a lower score indicating greater effect of the health condition. The EQ-5D has five dimensions—mobility, self-care, usual activities, pain or discomfort, and anxiety or depression.
2 The authors defined “mild visual impairment” as visual acuity between 20/32 and 20/63; “moderate visual impairment” as visual acuity between 20/80 and 20/60; and “severe visual impairment” as visual acuity worse than or equal to 20/200.
vision impairment (Park et al., 2015). The impact of vision impairment on people with chronic conditions is explored further later in this chapter.
Two studies indicated that the QOL impact of vision loss may be perceived differently by health care providers than by the patients themselves. One study administered time-trade-off utilities to Canadian medical students and patients for different levels of vision loss (anchors were death = 0 and perfect vision = 1.0); the study found that medical students tended to underestimate the impact of vision loss (Chaudry et al., 2015). In a similar study in China, utility values for mild glaucoma and severe glaucoma were obtained from glaucoma patients and ophthalmologists; the ophthalmologists’ utility ratings for mild glaucoma were significantly higher than the patients’, suggesting that physicians may underestimate the impact of mild glaucoma on QOL (Zhang et al., 2015).
Loss of vision affects patients’ ability to work or care for themselves (or others), and it affects numerous casual activities such as reading, socializing, and pursuing hobbies (Brown et al., 2014). Vision impairment makes it more difficult to perform the basic self-care activities of daily living such as eating and dressing as well as instrumental activities of daily living such as shopping, financial management, medication management, and driving (Brown et al., 2014; Haymes et al., 2002; Whitson et al., 2007, 2014). Most studies have found that vision loss has a greater impact on dependency in instrumental activities of daily living than in basic activities of daily living. The instrumental activities of daily living are critical to one’s ability to function in modern society. In particular, the loss of near vision affects one’s ability to perform a variety of tasks that involve reading (e.g., getting information from medication labels, balancing bank statements, or following recipes), recognizing faces and images (e.g., socializing, playing cards, using a smartphone), or manipulating small objects (e.g., sewing, replacing batteries). One cross-sectional study found that individuals with visual impairment, defined as a best-corrected binocular presenting visual acuity of 20/30 or worse, had greater disability across functional measures, such as task performance, walking speeds, and driving when compared to people with normal vision and even uncorrected refractive error3 (Zebardast et al., 2015). Visual field deficits affect one’s ability to perform tasks that require ambulation in challenging settings (e.g., moving along crowded city streets, negotiating stairwells) or the use of peripheral vision (e.g., driving).
3 Uncorrected refractive error was defined as a binocular visual acuity of less than or equal to 20/30 that improved to greater than 20/30 with subjective refraction.
Due to the challenges that vision impairment imposes for independent living, older adults with vision impairment may be more likely to require long-term care. In the Australian Blue Mountains Eye Study, with each line of reduction in presenting visual acuity at baseline, there was a 7 percent increased risk of subsequent nursing home placement (Wang et al., 2003). For participants in the Beaver Dam Eye Study, the odds ratio for nursing home placement was 4.23 (95% confidence interval [CI] = 2.34, 7.64) for low best-corrected visual acuity in the better eye, 5.00 (95% CI = 2.28, 10.94) for poor near vision, and 2.40 (95% CI = 1.46, 3.92) for poor contrast sensitivity, after adjustment for age, sex, self-rated health, and arthritis (Klein et al., 2003).
For persons with vision loss who desire to be a part of the workforce, vision impairment often poses barriers to employment opportunities (O’Day, 1999). Unfortunately, employment statistics pertaining to Americans with vision loss are lacking because available nationally representative data sources, such as the U.S. Census, group persons with vision impairment with all people who have sensory impairments or with people with sensory or communication impairments (U.S. Census Bureau, 2014).
Mobility and Falls
In a person with intact eyesight, the primary sense used to navigate three-dimensional space is vision. Mobility is therefore greatly affected by vision loss, whether resulting from changes in visual acuity, visual fields, depth perception, or contrast sensitivity (Bibby et al., 2007; Lord and Dayhew, 2001; Marron and Bailey, 1982). In the Salisbury Eye Evaluation (SEE) project, vision impairment (defined by visual acuity or visual field deficit) was significantly associated with self-reported difficulty with walking or going up or down steps (Swenor et al., 2013). Also in the SEE project, visual field deficits—but not visual acuity or contrast sensitivity deficits—were predictive of a slower-than-usual gait speed while navigating an obstacle course (Patel et al., 2006). A study from the United Kingdom found that 46 percent of frail elderly individuals admitted for hip fracture in two hospital districts had visual impairment, most frequently untreated cataract (49 percent) and macular degeneration (21 percent), but also uncorrected refractive error (17 percent); the visually impaired hip fracture patients were less likely than those without vision impairment to be under an eye provider’s care and more likely to live in areas of social deprivation (Cox et al., 2005). In the Low Vision Rehabilitation Outcomes Study, 16.3 percent of participants referred to vision rehabilitation at 28 U.S. centers indicated that one of their chief vision-related problems was mobility (Brown et al., 2014).
Multiple peer-reviewed studies have documented a relationship between vision impairment and falls (Crews et al., 2016a; Lord, 2006). A 2016 study by Crews and colleagues that used 2014 BRFSS data to analyze the state-specific annual prevalence of falls among persons aged 65 years or older found that 46.7 percent of persons with severe vision impairment (state prevalence range 30.8–59.1 percent) and 27.7 percent of older adults without such impairment (state prevalence range 20.4–32.4 percent) reported having fallen during the previous year (Crews et al., 2016a). The visual parameters that have been strongly and consistently associated with falls include poor contrast sensitivity, reduced depth perception, and visual field loss (de Boer et al., 2004; Ivers et al., 1998; Klein et al., 2003; Lord and Dayhew, 2001; Lord et al., 1991, 1994; Nevitt et al., 1989). A review of studies that reported the univariate relationship between visual deficits (defined variously) and falls found that the relative risk ratios across studies was 2.5 (CI = 1.6, 3.5) (Rubenstein and Josephson, 2002).
Evidence is limited or conflicting on the need for vision assessment and specific interventions to reduce falls among visually impaired populations. The U.S. Preventive Services Task Force determined that vision correction was among several potential interventions that “lack[ed] sufficient evidence for or against use in prevention of falls in community-dwelling older adults” (Moyer, 2012, p. 200; see also, Schneider et al., 2012). Unfortunately, the visual deficits most strongly linked to fall risk (contrast sensitivity, depth perception, and visual field deficits) are generally less amenable to remediation than visual acuity. Other factors such as weakness, other chronic conditions, and the use of medications are also associated with falls, suggesting that successful interventions to reduce falls in visually impaired populations will require a multi-pronged approach (Steinman et al., 2011). Evidence is needed to determine which training aspects, equipment, and environmental modifications are most effective at reducing falls and improving mobility. However, it is the committee’s assessment that there remains a role for vision rehabilitation in mitigating fall risk associated with vision loss.
Vision impairment has been shown to be associated with an increased risk of fractures in multiple studies. In the Framingham Eye Study, which included a subset of participants from the Framingham Study Cohort, those participants with visual acuity worse than 20/100 were more than twice as likely to have had hip fractures than participants with visual acuity of 20/25 or better (relative risk [RR] = 2.17; 95% CI = 1.24, 3.80) (Felson et al., 1989). In the EPIDOS Prospective Study, among a prospective cohort of 7,575 French women, those with visual acuity of 2/10 (using the decimal Snellen fraction, thus equivalent to 20/100) or worse had a RR of 4.3 (95%
CI = 3.1, 6.1) of hip fracture compared to those with visual acuity better than 7/10 (roughly equivalent to 20/30) (RR = 1.0) (Dargent-Molina et al., 1996). Various other aspects of visual impairment besides poor visual acuity have been shown to be associated with an increased fracture risk. In the Study of Osteoporotic Fractures, white women in the lowest quartile of depth perception measures were estimated to have a 40 percent increased risk of fractures compared with women in the other three quartiles (RR = 1.4; 95% CI = 1.0, 1.9), and the risk of fractures increased by 20 percent for each standard deviation decrease in low-frequency contrast sensitivity (RR = 1.2; 95% CI = 1.0, 1.5) (Cummings et al., 1995). Furthermore, in the same cohort, women with mild, moderate, or severe binocular visual field loss had an increased risk of hip fractures when compared with women without binocular visual field loss, and women with moderate or severe visual field loss had an increased risk of non-hip and non-spine fractures compared with women without binocular visual field loss (Coleman et al., 2009).
Studies have suggested that reversing vision impairment from cataract may be protective against fractures. A randomized controlled trial that evaluated expedited versus routinely scheduled cataract surgery in 306 women found that women with expedited cataract surgery had a 67 percent lower risk of fractures within 1 year after surgery than women with routinely scheduled surgery (RR = 0.33; 95% CI = 0.1, 1.0) (Harwood et al., 2005). A large study of more than 1.1 million men and women with cataract in the national U.S. Medicare database found that compared to patients with cataract who did not undergo surgery, patients with cataract surgery had a 16 percent lower risk of hip fracture (odds ratio [OR] = 0.84; 95% CI = 0.81, 0.87) and a 5 percent lower risk of any fracture (OR = 0.95; 95% CI = 0.93, 0.97). Furthermore, this protective association was modified by the effects of age and systemic disease burden, and the apparent protective relationship between surgery and fracture, based on having a high Charlson Comorbidity Index score, was even stronger among participants who were elderly or ill (Tseng et al., 2012).
The protective association between cataract surgery and fractures may extend beyond a reduction in fracture risk. In a recent study of the same large population of Medicare beneficiaries with cataract, those who had cataract surgery experienced 27 percent decreased risk in long-term mortality compared with those without cataract surgery (hazards ratio [HR] = 0.73; 95% CI = 0.72, 0.74) (Tseng et al., 2016). Similar to what was seen in the study of cataract surgery and fractures, the protective association between cataract surgery and mortality was modified by the effects of age and systemic disease burden, where patients who were elderly or who had a moderate burden of systemic disease experienced even stronger protective effects than the overall population. Although this study did not examine the
mechanisms of the protective effect between cataract surgery and mortality and the study design does not permit conclusions about causation, the reduction in the risk of fractures and accidents was proposed as a contributing factor in the reduced risk of death. The protective association between cataract surgery and mortality in this study was supported by additional data from two earlier studies in the Blue Mountains region, west of Sydney, Australia, both of which demonstrated that patients with vision improvement after cataract surgery had decreased mortality risk compared with patients with vision impairment due to cataract who had not undergone surgery or those with persistent vision impairment after cataract surgery (Fong et al., 2013, 2014).
People with vision loss are at higher risk for several types of injury. Of these, the link between vision loss and fall-related injuries has been most clearly documented. In a population-based cohort of Latinos in California, a greater risk of injurious falls was reported in those with both central vision impairment (OR = 2.76; 95% CI = 1.10, 7.02) and peripheral vision impairment (OR = 1.40; 95% CI = 0.94, 2.05) (Patino et al., 2010). A loss of visual field was associated with fall-related fractures, and a relationship between a recently acquired decline in visual acuity and falls with fracture was observed in the Blue Mountain Eye Study (Hong et al., 2014; Klein et al., 2003). Interestingly, both falls and falls with fracture were more likely in participants with a unilateral, rather than bilateral, visual acuity deficit, which is similar to the findings of an earlier study, suggesting that poor depth perception may be a contributor to falls (Felson et al., 1989). Indeed, poor depth perception has been associated with hip fracture in other epidemiological studies (Cummings et al., 1995). Poor contrast sensitivity is also associated with risk of fall-related fractures (de Boer et al., 2004).
In a prospective study of seniors between the ages of 75 and 80 years, lowered vision4 at baseline was associated with an increased risk of injurious accidents requiring hospitalization over 10 years of follow-up (Kulmala et al., 2008). A visual acuity worse than 0.3 on the Landolt ring chart (roughly equivalent to 20/65) was not associated with a risk of injurious accidents, possibly because persons with more severe visual impairment restricted their activities, resulting in less opportunity for injury. However, in a separate study that used the National Health Interview Survey (NHIS)
4 Visual acuity was assessed using the Landolt ring chart, which consists of 13 lines in which visual acuity is scored from 0.125 (worst), if the person can only see the first line, to 2.0 (best) if the person can correctly see the last line. Visual acuity between 0.3 and 0.5 in the better eye was defined as lowered vision, and vision better than 0.5 was defined as normal vision.
to follow more than 100,000 adults for up to 7 years, severe bilateral vision impairment was associated with a risk of death due to unintentional injury (HR = 7.4; 95% CI = 3.0, 17.8) (Lee et al., 2003).
Compared to people with normal vision, those with vision impairment are at a higher risk for depression, anxiety, and other psychological problems (Kempen et al., 2012). Among older adults with vision impairment, the rates of depression and anxiety are significantly higher than among both individuals of similar ages without vision impairment and those of similar ages suffering from other chronic conditions, such as asthma or chronic bronchitis, heart conditions, and hypertension (Kempen et al., 2012). Distress related to vision loss is more strongly correlated with depression than other key risk factors such as negative life events or poor health status (Rees et al., 2010). Among visually impaired individuals, those with depressive symptoms report more functional limitations. The reasons for the relationship between depression and poor visual function are unclear and may be bi-directional, but patient-level differences in eye disease and general medical condition did not account for the observed relationship (Rovner and Casten, 2002; Rovner et al., 2006). One randomized, controlled trial of an integrated mental health and vision rehabilitation program (compared with vision rehabilitation with non-directed supportive therapy) for patients with macular degeneration and subsyndromal depressive symptoms found significantly reduced rates of depression symptoms and better functional outcomes in the intervention group (Rovner et al., 2014). This work suggests that some of the functional and affective consequences of vision loss are remediable.
As discussed in Chapter 2, children with uncorrected refractive error are more likely to underperform on some metrics of academic performance (Kulp et al., 2016). Academic problems have been found to be negatively associated with anxiety, with the frequency increasing with age in both children and adolescents (Mazzone et al., 2007). Similarly, among adolescents, vision impairment is associated with an increased prevalence of psychopathological symptoms, including depression and anxiety (Garaigordobil and Bernarás, 2009). An analysis of data from NHIS did not show evidence for a direct relationship between vision impairment and death from suicide (HR = 1.50; 95% CI = 0.90, 2.49); however, the study did indicate an indirect effect of visual impairment on death from suicide due to poorer self-rated health (HR = 1.05; 95% CI = 1.02, 1.08) and the number of non-ocular health conditions (HR = 1.12; 95% CI = 1.01, 1.24). These results suggest that people with vision impairment may be at greater risk of suicide due to vision impairment’s association with poor general health (Lam et al., 2008).
Several studies have found that cognitive impairment is more prevalent and progresses more rapidly in older adults with vision impairment than in those without (Lin et al., 2004; Ong et al., 2013; Reyes-Ortiz et al., 2005; Rogers and Langa, 2010; Tay et al., 2006; Whitson et al., 2007). About 4 percent of community-dwelling persons over age 65 have both cognitive and vision impairments, making the co-occurrence of these problems more prevalent than such well-recognized conditions as Parkinson’s disease and emphysema (Whitson et al., 2007). People with age-related macular degeneration (AMD) have higher rates of cognitive impairment than their peers, lower scores on cognitive tests, and a higher risk of incident dementia (Baker et al., 2009; Clemons et al., 2006; Klaver et al., 1999; Pham et al., 2006; Wong et al., 2002; Woo et al., 2012). Other studies suggest that, even without dementia, AMD patients still perform more poorly on tests of verbal fluency and memory (Clemons et al., 2006; Whitson et al., 2010, 2015; Wong et al., 2002). Research has failed to demonstrate a clear genetic link between AMD and dementia (Butler et al., 2015; Souied et al., 1998). These results suggest more research is needed to fully assess the reasons behind the link between vision and cognitive impairment in adults.
In children, uncorrectable vision impairment frequently occurs in the context of comorbid conditions, making it difficult to quantify the direct impact of visual impairment and blindness on cognitive skills, academic performance, and QOL. Many children who have been diagnosed with neurodevelopmental disorders (genetic or acquired) have been found to also have an associated vision problem that has led to visual impairment. Current research focuses on determining the prevalence of these eye health and vision disorders that occur with the underlying neurodevelopmental diagnosis (Salt and Sargent, 2014). For example, children with cerebral palsy have been found to have a higher prevalence of strabismus, visual impairment due to uncorrected refractive error, eye movement disorders, and visual perceptual deficits than normally sighted children of the same age (Lew et al., 2015; Salt and Sargent, 2014). A higher rate of vision impairment has also been documented for children with Down syndrome (Cregg et al., 2003). It is difficult to ascertain the influence of the vision loss on cognitive or academic function in diagnoses that are already associated with cognitive impairment. One study demonstrated that children diagnosed with toxoplasmosis who present with reduced vision perform more poorly than children diagnosed with toxoplasmosis without vision impairment on verbal and performance measure of intellectual ability (Roizen et al., 2006). A meta-analysis on children with cerebral palsy found that visual perceptual deficits were prevalent in those children but none of the studies had a control comparison group (Ego et al., 2015). These children often perform
below the level expected for their chronological ages, yet they have neither been categorized as visually impaired, nor referred for services (Flanagan et al., 2003).
Although an association exists between vision impairment—as well as some specific eye disorders—and cognition, the mechanisms underlying this relationship are unclear. One possibility is that diseases of the eye have a negative effect on cognitive processes, either directly or indirectly. In people with vision impairment, the loss of cognitively stimulating activities, such as reading, may diminish other cognitive abilities (Lindenberger and Baltes, 1994). Additionally, the brain is known to change in response to decreased visual input, and these changes may affect regions or neuronal pathways that support cognitive processes (Liu et al., 2007, 2010; Pascual-Leone et al., 2005). A second possibility is the “common cause” theory, which holds that genetic, environmental, or medical risk factors cause disease in the brain and eye simultaneously (Klaver et al., 1999; Lindenberger and Baltes, 1994). Another possibility is that confounding factors, such as behavior and economic status, contribute to the observed relationship between vision impairment and cognitive impairment.
The prevalence of co-existing impairment in vision and hearing, also referred to as dual sensory impairment (DSI), increases markedly with age. A range from 9 to 21 percent of adults over the age of 70 possess some degree of DSI (Saunders and Echt, 2007). In an Australian cohort, the prevalence of DSI was even higher, reported to be 26.8 percent in participants ages 80 and older (Schneider et al., 2012). In a cross-sectional study of a random sample of 446 older adults (mean age 79.9 years) from Marin County, California, eight measures of visual ability were associated with risk of hearing impairment (defined as moderate bilateral hearing loss, threshold >40 dB) (Schneck et al., 2012). However, the relationship between vision impairment and hearing impairment only achieved statistical significance for three measures of visual acuity in low contrast conditions. Additional research is needed to determine whether vision loss is an independent risk factor for hearing loss and, if so, what factors underlie this relationship.
Several studies report associations between vision impairment and an increased risk for all-cause and injury-related mortality, as compared to controls with normal vision (Christ et al., 2014; Lam et al., 2008; Lee et al., 2002, 2003; Zheng et al., 2014). One possible cause of the greater mortality
in visually impaired people may be their elevated risk of accidents and falls. In the longitudinal study by Christ and colleagues (2014), the relationship between worse visual acuity and mortality was mediated by disability in instrumental activities of daily living, which suggests that some deaths may result from an impaired ability for self-care and disease management.
The relationship between vision impairment and mortality is certainly confounded by medical conditions (e.g., diabetes, obesity, hypertension, autoimmune disorders), lifestyle factors (e.g., smoking, alcohol use), and socio-demographic factors (e.g., race, age, socioeconomic disadvantage). As detailed in the next section, the complicated interplay between eye health and other medical comorbidities is an important factor in monitoring and reducing the overall public health burden of vision loss.
The Office of the Assistant Secretary for Health defines chronic conditions as, “conditions that last a year or more and require ongoing medical attention and/or limit activities of daily living” (Goodman et al., 2013, p. 3). Chronic conditions are associated with an increased risk of “early mortality, poor functional status, unnecessary hospitalizations, adverse drug events, duplicative tests, and conflicting medical advice” (HHS, 2010, p. 2; see also, Hwang et al., 2001; Vogeli et al., 2007; Wolff et al., 2002). Expenditures related to chronic conditions are substantial, with an estimated 66 percent of total health care spending attributable to care for Americans with multiple chronic conditions (HHS, 2010). Approximately 14 percent of Medicare beneficiaries with six or more chronic conditions accounted for 46 percent of total Medicare spending in 2010, while the 32 percent of beneficiaries with one or fewer chronic conditions accounted for 7 percent of spending (CMS, 2012).
Irreversible vision impairment resulting from eye disease should be considered a chronic condition; it can amplify the adverse effects of other illnesses and injuries, and people with vision loss commonly live with multiple chronic conditions. As of 2012, 117 million people had at least one chronic condition, with one in four adults reporting two or more chronic health conditions (CDC, 2016). Data from the Medical Expenditure Panel Survey show that among Americans over age 65 with eye disease, four out of five also had at least one of the following conditions: hypertension, heart disease, diabetes, or arthritis (Anderson and Horvath, 2004). According to a 2008 NHIS, a substantial number of people with chronic diseases reported trouble seeing: 34.8 percent of those with chronic kidney disease, 30.9 percent of those with stroke, 23.8 percent of those with coronary heart disease, 23.6 percent of those with diabetes, 22.1 percent of those with arthritis, 19.7 percent of those with patients, and 19.4 percent of those with
hypertension (Crews and Chou, 2012). Whether or not any causal relationship exists between vision impairment and non-ocular comorbidities, it is clear that any successful efforts to alleviate the burden of vision impairment and loss will need to take comorbidities into account.
Vision Loss Amplifies the Effects of Other Conditions
A study of individuals ages 65 and older found that patients with a visual impairment and any of several other illnesses or conditions were many times more likely to have difficulty performing basic physical and social tasks than individuals in the same age range without visual impairment and without the particular illness or condition (Crews et al., 2006). For example, elderly individuals with severe depression, visual impairment, or both were 10.0, 2.9, and 23.9 times more likely, respectively, to have moderate or severe limitations in their ability to socialize than people without either severe depression or visual impairment. Table 3-2 details the increased odds of encountering difficulty when undertaking these basic physical and social tasks among persons with visual impairment or a given comorbidity, or both. Whether or not comorbid vision impairment directly caused the excess disability (which cannot be inferred from descriptive
TABLE 3-2 Adjusted Odds Ratio for the Self-Reported Difficulty Performing Tasks Among U.S. Adults Ages 65 and Older with Vision Impairment and/or Other Condition or Disease
|Disease or Condition Reference Group||Condition or Disease||Vision Impairment Only||Condition or Disease + Vision Impairment|
|Low back pain||2.4||1.9||2.9||3.2||5.9||5.7|
NOTES: All figures describe adjusted odds ratio of encountering moderate to severe limitations when performing either physical or social activities among persons with vision impairment or a comorbidity or both as compared to persons without a vision impairment or the relevant illness/condition. Physical activity refers to ability to walk 0.25 mile. Social activity refers to ability to socialize.
SOURCE: Adapted from Crews et al., 2006.
data), vision impairment may help identify high-risk individuals or individuals with unmet needs who could be targeted for services and interventions across a variety of other clinical specialties.
Both cognitive impairment and vision impairment are disabling in their own right, but the co-occurrence of the two has been associated with even higher rates of disability and low self-rated health (Whitson et al., 2007, 2012a). Dual sensory impairment (concurrent vision and hearing deficits) has been associated with a higher risk of cognitive decline, disability, depression, and mortality (Gopinath et al., 2013; Heine and Browning, 2014; Lee et al., 2007; Lin et al., 2004; Schneider et al., 2011). Evidence is inconclusive regarding whether the combined effects of vision impairment and other impairments (cognition or hearing) on outcomes are synergistic or merely additive (Schneider et al., 2011; Whitson et al., 2007).
Vision Loss Complicates the Management of Other Conditions
As reviewed above, vision loss creates significant challenges in daily life. The challenge of not being able to see well can affect various vision-reliant tasks that are frequently required for good chronic disease management, including self-care (e.g., foot checks in diabetics, preparing nutritious meals) and transportation (e.g., getting to and from clinic visits). In addition, vision loss may create difficulties in medication adherence and management (e.g., reading pill bottles, ordering refills) so that individuals who develop vision loss associated with chronic conditions, such as diabetes or glaucoma, are at a disadvantage in managing those chronic conditions. For example, vision loss makes it difficult to properly administer medications such as insulin or eye drops. Thus, affected individuals are at risk of entering a “vicious cycle” of worsening health.
Other Conditions Affect the Management of Eye Disease
Comorbidities also affect patients’ ability to manage and cope with their vision impairment and eye health. One area of eye care where the impact of comorbid conditions has been studied is vision rehabilitation. Both cognitive impairment and depression have been associated with worse functional outcomes in vision rehabilitation (Rovner et al., 2002; Whitson et al., 2012b). A qualitative study of 98 older adults and their companions/caregivers in an outpatient vision rehabilitation clinic identified five themes regarding the impact of comorbid medical conditions on the patients’ experiences in vision rehabilitation (Whitson et al., 2011). Comorbidities had the following implications for the success of vision rehabilitation: (1) concurrent medical problems resulted in fluctuating health status with “good days and bad days” that were unrelated to eye disease, (2) comorbid
conditions (e.g., hearing impairment, cognitive impairment) often amplified communication barriers between patients and providers, (3) participants and caregivers felt “overwhelmed” by competing health care demands, (4) comorbidities tended to delay progress in vision rehabilitation programs because of unexpected health events (e.g., falls, hospitalization, disease flares), and (5) some barriers imposed by comorbid conditions seemed to be reduced by the effective involvement of an informal companion5 (Whitson et al., 2011). A second qualitative study focused on the impact of comorbid cognitive impairment in vision rehabilitation (Lawrence et al., 2009). This study interviewed 17 individuals with co-existing vision impairment and dementia, 17 family caregivers, and 18 vision or dementia health specialists involved in the patients’ care (Lawrence et al., 2009). The study found that vision-related service providers felt ill equipped to manage dementia-related needs, while visual needs were accorded a low priority by those providing dementia services; a lack of collaboration between the two services led to an overcautious approach (Lawrence et al., 2009).
Comorbidities can also affect patients’ ability to manage specific aspects of their eye care. In particular, the administration of eye drops can be challenging for patients with a limited range of motion in the neck, with arthritis or neuropathy involving the hands, or with cognitive impairments. The precise impact of these comorbidities on medication adherence and the proper administration of eye drops merits further research, but one multisite study that video-taped glaucoma patients self-administering a single drop reported that individuals with arthritis were significantly less likely to have the drop land in their eye (Sayner et al., 2015).
Few studies are available that examine the total costs associated with all eye disease and vision impairment on a national level. A 2013 analysis of the economic burden of vision loss and eye disorders that was commissioned by Prevent Blindness estimated prevalence and costs from National Health and Nutrition Examination Survey (NHANES) data, Medical Expenditure Panel Survey (MEPS) data, and data from the Survey of Income and Program Participation, the 2011 U.S. Census, and federal budgets (Wittenborn and Rein, 2013). This analysis estimated the direct and indirect costs attributable to vision loss and eye disease to be $138.9 billion in the United States in 2013 dollars and found that costs for individual states ranged from $250 million in Wyoming to more than $15.6 billion in California
5 A friend or relative with whom the participant had at least weekly contact.
(Wittenborn and Rein, 2013).6 The direct medical costs summed across all age groups attributable to, for example, diagnosed disorders, undiagnosed visual loss, and optometry7 visits were $48.7 billion, $3.0 billion, and $2.8 billion, respectively (Wittenborn and Rein, 2013). The total direct and indirect costs for eye disorders and vision loss per payer were $47.4 billion for government entities, $22.1 billion for private insurers, and $71.7 billion for patients (Wittenborn and Rein, 2013).
Table 3-3 provides a breakdown of the comprehensive costs by age group for major categories of direct and indirect costs associated with eye care in the United States. Directs costs associated with diagnosed vision impairments along with indirect costs associated with productivity loss account for approximately 70 percent of the comprehensive costs across all age groups. Medical vision aids, which include eyeglasses and contact lenses, are the next largest expense category. Nursing home expenses account for an additional 30 percent of indirect costs but are attributable only to the over-65 population. These data suggest that interventions targeting the prevention and reduction of vision impairment have the potential to reduce overall costs. Although more data are needed for a comprehensive analysis of this assertion, shifting the burden of vision expenditures away from the possible downstream consequences of severe vision impairment toward items and services that promote the earlier diagnosis and treatment of vision-threatening diseases or conditions would extend the productivity and function of populations with vision impairment.
The costs of eye disorders and subsequent vision loss are shared by the government, private insurance, and individuals, including patients and families. According to a recent analysis, the $47.4 billion that the government spends annually on eye disorders and vision loss is mostly for direct medical costs and long-term care (Wittenborn and Rein, 2013). One systematic review examined the average annual expense per patient in a cohort of Medicare beneficiaries and found per-patient costs in 2011 dollars to range from $12,175 to $14,029 for moderate vision impairment, $13,154 to $16,321 for severe visual impairment, and $14,882 to $24,180 for blindness (Köberlein et al., 2013). In comparison, the authors cited a mean expense of $8,695 for patients with no vision loss as the control, indicating
6 The state cost estimates were a function of the states’ populations within each age group. State populations were identified for the age groups 0–17, 18–39, 40–64, and 65+ based on the 2011 U.S. Census data. The burden estimate was divided by age for each age group to derive per-person costs for each group, then multiplied by the state population costs for each age group. These estimates do not include state-specific unit cost or utilization estimates (Wittenborn and Rein, 2013).
7 “These costs are measured separately from other medical costs in MEPS; they are not associated with diagnosis codes and are based on non-confirmed, self-reported expenditures” (Wittenborn and Rein, 2013, p. 2).
TABLE 3-3 Economic Burden of Eye Disorders and Vision Loss (in millions of dollars)
|Age Group||Comprehensive Costs (in $ millions)|
|Medical vision aids||$1,480||$3,335||$6,222||$2,199||$13,236|
|Undiagnosed vision loss||$48||$474||$1,702||$798||$3,022|
|Total direct costs||$5,086||$9,086||$22,246||$30,335||$66,752|
|Transfer deadweight loss||$47||$98||$538||$808||$1,490|
|Total indirect costs||$648||$13,075||$11,553||$46,941||$72,217|
|Total economic burden||$5,734||$22,161||$33,799||$77,276||$138,970|
|Loss of well-being measures|
|Disability adjusted life years lost||6.92||26.35||33.38||216.48||283.13|
a Transfer payment costs are not included in total.
SOURCE: Wittenborn and Rein, 2013.
that expenses for blind individuals can sometimes be more than double the control cost at the upper end of the range (Köberlein et al., 2013). The total of all these costs is substantial, considering that Medicare had 52.2 million beneficiaries in 2013 (CMS, 2014).
Private insurers covered approximately one-third of the total, or $22.1 billion (Wittenborn and Rein, 2013). As with public insurance, the majority of these costs ($20.8 billion) were related to direct medical costs and supplies (Wittenborn and Rein, 2013). Costs associated with diagnosed disorders were by far the most substantial costs for private insurers, at more than $17 billion. The relatively small amount spent for medical vision aids ($2.6 billion) reflects the limited available reimbursement coverage and accounts for the high spending burden for such aids by the individual payer ($9.7 billion) (Wittenborn and Rein, 2013). The rest of the costs are attributable to reimbursement for long-term care. The costs associated with diagnosed
blindness and vision impairment averaged (across all payers) $6,680 per year (Wittenborn and Rein, 2013). By way of comparison, the annual costs for all different types of diagnosed medical disorders average $3,432 per person (Wittenborn and Rein, 2013). Despite the high costs associated with vision impairment and loss, the per-person costs for vision correction average only $81 per year (Wittenborn and Rein, 2013). One expert suggested that the cost to expand all required pediatric vision-related services under the Patient Protection and Affordable Care Act of 2010 to all beneficiaries covered by private insurance would range from $1 to $2 per member per month (Spahr, 2015).
Individuals paid for slightly more than half—$71.7 billion—of the total cost of eye disorders and vision loss, “largely due to productivity and informal care losses” (Wittenborn and Rein, 2013, p. 5). Of that $71.7 billion covered by individuals, direct costs accounted for approximately $15.5 billion primarily for medical vision aids ($9.7 billion), diagnosed disorders ($4.7 billion), aids and devices ($749 million), and undiagnosed vision impairment ($372 million) (Wittenborn and Rein, 2013). Indirect costs accounted for more than $56 billion of the individual costs. Those indirect costs were due to productivity losses caused by reduced workforce involvement and lower wages, the costs of informal care, and long-term care costs (Wittenborn and Rein, 2013). One national survey of working age adults found that 52 percent of them had less than $1,000 on hand to pay for out-of-pocket expenses associated with the diagnosis of an unexpected serious illness; 28 percent had less than $500 (Aflac, 2015).
Figure 3-1 indicates that the costs attributed to eye and vision health increase with age across all payers and that the over-65 population is responsible for the vast majority of expenses for all payers, except private insurance. This is not surprising given the individual costs attributable to specific age-related eye diseases and conditions and the prevalence of diabetes in older populations. For example, diabetic retinopathy cost the United States $493 million in 2004, with 60 percent of the direct medical costs incurred by 40 to 60 years olds (Rein et al., 2006). Similarly, in 2009, the estimated costs to Medicare from glaucoma reached $748 million (Quigley et al., 2013). Schmier and Levine (2013) estimated the total loss in gross domestic product related to AMD was almost $42 billion in 2012 dollars. The costs attributable to individual cases vary by the severity of the disease or condition. For example, the distribution of AMD-associated costs varies by disease stage, “with greater cost for diagnosis procedures with earlier AMD and more on caregiving and institutional care with wet AMD” (Schmier and Levine, 2013). One study found a four-fold increase in direct ophthalmology-related costs between asymptomatic ocular hypertension/earliest glaucoma ($623 per year) and end-stage glaucoma/blindness ($2,511 per year) (Varma et al., 2011). The authors suggested
that “early identification and treatment of patients with glaucoma and those with ocular hypertension at high risk of developing vision loss may reduce the individual burden of disease on [health-related quality of life] and also may minimize personal and societal economic burdens” (p. 5).
In addition to incurring direct costs related to vision care, people with vision impairment tend to experience a lower QOL and decreased health status (as discussed in this chapter), and vision loss can complicate and exacerbate other comorbid conditions, driving up costs and worsening outcomes. For example, Bramley and colleagues (2008) demonstrated among Medicare beneficiaries with glaucoma that patients with any vision loss had 46.7 percent higher costs compared with patients without vision loss; the higher costs were the result of the increased risk for nursing home admission, depression, falls, accidents, and injury. These outcomes account for some of the most substantial health expenditures. As such, in order to secure population-level improvements in the field it will be critical to understand that the costs associated with vision impairment and eye disease are borne not only by individuals, but also by their caregivers, taxpayers, and employers. Without dedicated action, society as a whole will increasingly bear the burden of the direct costs from increasing yet avoidable Medicare
spending and of the indirect costs from substantial lost productivity and a reduced labor force.
Vision impairment results in significant expenditures, both direct and indirect, and has the potential to affect almost every aspect of a person’s life. Vision loss affects more than one’s ability to see the world clearly. The consequences of vision impairment often negatively impact QOL, including the number of physical and mental unhealthy days and overall dissatisfaction with life. Individuals with vision impairment are also more likely to experience restrictions in their independence, mobility, and educational achievement, as well as an increased risk of falls, fractures, injuries, poor mental health, cognitive deficits, and social isolation.
Vision loss also amplifies the effects of other chronic conditions and is a chronic condition itself. People with a vision impairment and other illnesses or conditions are more likely to have difficulty performing tasks and reporting poor health. Vision loss can also complicate chronic disease management, including self-care, transportation to and from doctor’s appointments, and the proper administration of medicine. Moreover, other conditions may affect the management of eye disease, including vision rehabilitation to improve the functionality and quality of life for those with vision impairments.
No studies are available on the total costs attributable to the promotion of eye and vision health and the economic impact of vision loss in the United States. However, the few studies available that have looked at overall direct and indirect costs found that national costs are in the billions each year and vary substantially by state. Total costs also vary by age and by payer, with substantial costs incurred by individuals, including costs of caring for family members with vision impairment. Population health approaches to improve eye and vision health will need to focus on the direct and indirect costs as objective measures of the impact of vision impairment but also as measures of equity among populations most likely to be affected by vision impairment.
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