Vision problems are among the top ten conditions responsible for disability among Americans;these conditions are often associated with an increased risk of death. This study will utilize structural equation modeling (SEM) to study linkages between visual impairment and other ocular conditions with morbidity status and mortality risk to answer the following questions: 1) What is the relative contribution of ocular system declines to changes in overall health and functional status?;2) Do improvements in ocular health, either via effective medical management of ocular conditions or risk factor modification (e.g., smoking cessation) lead to improvements in functional status and lower mortality risk?;3) Do ocular system declines directly lead to an increased risk of mortality, or do these changes also indirectly influence mortality risk via adverse impacts on functional status indicators?;and 4) What is the role of visual impairment (VI) in the aging process? That is, is VI simply a symptom of underlying frailty or is it independently associated with worsening health? Data for this study will come from the Salisbury Eye Evaluation (SEE) Project, a study of vision and function in older adults. The study enrolled a random sample of 2520 community residents 65 to 84 years of age. Participants underwent comprehensive vision testing and ocular examinations, and were administered multiple tests of functional status, portions of which were repeated in three subsequent rounds over a 10-year period. Mortality status was obtained thru 2003;full linkage of the entire cohort with the National Death Index (NDI) thru 2009 is proposed as part of this application and will yield a sufficient number of deaths and person-years of follow-up to reliably detect hazard ratio associations smaller than 1.34 with 80% power. This statistical power, in combination with the comprehensive assessment of ocular and functional status indicators assessed over four time periods, will enable us to: 1) examine associations between change in visual acuity levels and change in functional mobility and other morbidity indicators (e.g., grip strength) and depressive symptoms among SEE participants following adjustment for time-varying ocular conditions, and select health conditions and chronic disease risk factors;and 2) examine associations between vision related factors (e.g. changes in visual acuity status, presence of ocular conditions, ocular healthcare utilization) and health-related factors (e.g. health behaviors, health conditions, and mortality risk). Proposed study aims support key goals of the National Eye Institute (NEI) Ocular Epidemiology Strategic Planning Report, including: 1) Determine the burden of eye diseases and their visual outcomes in a changing population, and 2) develop new methodologies to support ophthalmic epidemiological research.
Vision problems are among the top ten conditions responsible for disability among Americans and are also associated with an increased risk of death. This study will examine, in a comprehensive manner, the role of the development of these vision conditions on health, functioning, and risk of death. It will also determine if improvements in visual functioning due to either treatment (e.g., cataract surgery) and/or improvements in lifestyle (e.g., smoking cessation) leads to improved health and a lower risk of death.
|Christ, Sharon L; Lee, David J; Lam, Byron L et al. (2014) Structural equation modeling: a framework for ocular and other medical sciences research. Ophthalmic Epidemiol 21:1-13|
|Lam, Byron L; Christ, Sharon L; Zheng, D Diane et al. (2013) Longitudinal relationships among visual acuity and tasks of everyday life: the Salisbury Eye Evaluation study. Invest Ophthalmol Vis Sci 54:193-200|