In this study, we evaluated the impact of uveitis on the QOL of children with JIA or idiopathic uveitis and determined that visual function is an important and often overlooked component of QOL. Our results showed a moderate correlation between visual function and QOL in children with uveitis that was not evident in those without uveitis. Likewise, our results suggested that QOL studies should incorporate visual disability in their analysis since many children with JIA also suffer from uveitis.
Our population of patients with uveitis had more ocular symptoms and suffered from greater visual dysfunction as measured by our EYE-Q (p = 0.038). Although the visual acuity of children with and without uveitis was similar, a moderate correlation existed between visual function and QOL in the uveitis group. This suggested that visual acuity alone was not an adequate measure of visual function and that both subjective and objective measures were necessary. Likewise, the inclusion of children with idiopathic uveitis served as a comparison group that emphasized the importance of visual function since these children do not have physical disabilities related to arthritis.
QOL has been defined by the World Health Organization as an “individual's perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards, and concerns.”11
It has been an important outcome and may largely be defined by one's degree of health (ie, health-related QOL). Valid and reliable instruments that estimate the impact of overall health, as well as signs and symptoms of specific conditions have been pertinent to this assessment, especially in disease populations. Standardized measures of health status that encompass a wider concept of QOL have become increasingly important.12
Visual disability has the potential to impact an individual's ability to perform activities of daily living. More specifically, clinically significant impairment would likely lead to difficulty performing tasks that rely on vision. However, there have been no validated instruments to assess visual function in children 8 to 18 years of age, which has led our group to develop our own questionnaire. Objective measures such as visual acuity, visual field, color vision, and contrast sensitivity have been used to determine outcome and visual function in children.13
It has remained uncertain whether these measures alone accurately assess one's degree of visual impairment, and whether they truly represent the patient's perspective of the impact of their disease. Interestingly, both visual functioning and general health status have been considered important measures of QOL and provided complementary information in adult patients with uveitis.14
Health-related QOL in children with arthritis has been thought to be related to various domains such as physical function, pain, ability to cope with disease, psychosocial adjustment, social functioning and impact of disease.15
Although physical function is not the only component of QOL, assessment tools in pediatric rheumatology have been comprised largely of instruments that measure musculoskeletal function, health-related QOL, and overall QOL.16-18
As a result, the impact of uveitis in this population may be underestimated since the effects of visual impairment on QOL have not been examined.
To date, all studies examining QOL in children with JIA have used physical function assessments (ie, Childhood Health Assessment Questionnaire) either as proxies for or predictors of QOL.17,19
This monolithic perspective may result in an underestimation of QOL as its measurement has focused exclusively on musculoskeletal function without considering the potential significance of the disease's ocular manifestations. No studies on visual disability have been conducted in patients with JIA other than studies of visual acuity.5
Likewise, no validated instruments that assess vision related QOL exist to evaluate visual disability as a component of QOL in an 8- to 18-year-old population. In general, physicians rely on objective measures such as visual acuity and contrast sensitivity to determine visual outcome.6,13,20-24
One instrument, the Children's Visual Function Questionnaire, is specific for children ≤7 years of age, and the second, the LV-Prasad Questionnaire, is not culturally relevant.25-27
The adult standardized visual function questionnaires (ie, the National Eye Institute—Visual Function Questionnaire) contain items that are inappropriate for use in children such as driving and shopping.28
Vision related QOL may be assessed by determining the degree of visual impairment in activities of daily living, ie, impaired daily functioning secondary to visual difficulties is a proxy for vision related QOL. To develop our questionnaire (EYE-Q), we selected relevant items from existing instruments and consulted pediatric rheumatologists, pediatric ophthalmology professionals (eg, ophthalmologists, optometrists, clinical research technicians), and children with and without ocular disease. Input from these individuals was used to develop other relevant questions, and refine the phrasing of the items and the response format. This provided us with both face and content-related evidence for validity which primarily depends on the subjective agreement of experts.29
Children who were 8 to 18 years of age then evaluated our instrument for comprehensibility, relevance and ease of format. After this initial assessment, we administered it to children with uveitis as described in this manuscript which further validated our instrument since it was administered to children with and without visual impairment, and was compared to a gold-standard measure of overall QOL. We have since incorporated questions to evaluate photosensitivity, night vision, the use of visual aids (eg, magnifying glass), and the child's perception of overall visual function. We have also created age-appropriate subsections specific for children 8 to 15 and 16 to 18 years of age since cognitive abilities and the importance of performing certain tasks differ with age. This instrument is now undergoing additional validity and test–retest reliability studies.
Our data have been consistent with previous studies showing that children with JIA and uveitis are primarily Caucasian, female, and have (+) ANAs. Their joint involvement was similar to children without uveitis except for increased morning stiffness. This may be a consequence of children with oligoarticular disease having an increased incidence of uveitis but less joint involvement, and children with polyarticular disease having greater joint involvement but less uveitis.
There were a number of limitations to this study. The study design was observational and cross-sectional with a limited recruitment period of 6 months. This prevented the determination of the effects of disease flare on QOL since most of the subjects were not in flare during the time of analysis. The population was homogenous and consisted primarily of Caucasian children with sufficient disease control wherein they had minimal joint and ocular involvement. Inclusion of a larger number of children with idiopathic uveitis or the different JIA subtypes (psoriasis, poly, and oligo) with more varied disease activity may allow us to better detect differences in QOL. The size of our cohort also precluded the performance of multiple linear regressions to test for possible predictors of overall QOL.
This study provided evidence of the importance of all components of QOL. The results reported suggested that our visual function questionnaire has clinical utility as an outcome measure. We are currently conducting further validity and reliability studies in a population of children with a wide range of vision. We plan a larger cross-sectional study that examines the effects of both visual and physical disability on a more diverse JIA and uveitis population. Likewise, a longitudinal study would enable us to determine the overall impact of visual impairment in children with JIA and uveitis long-term and the effects of disease flares, medication use, and other QOL-related variables on overall QOL.
In conclusion, current QOL studies have focused on the physical component of JIA regardless of the extent of musculoskeletal involvement. It is likely that both overall disability and QOL have been underestimated among children with uveitis as the instruments used in these studies do not take into account the ophthalmologic diagnoses or consequences. Knowledge of the impact of inflammatory eye involvement on visual function and QOL of all patients will lead to the development of better interventions to ensure these children have the best opportunities to lead normal lives as children and adults. Only by understanding how and to what extent QOL is negatively impacted by visual disability will we be able to identify these children's needs and provide requisite assistance to maintain function and sustain optimal levels of QOL.