This is an SBIR Phase II proposal directed at the continued development of a diagnostic for the early detection of age-related macular degeneration (AMD). It relies on a functional test of dark adaptation kinetics (the transition from being light-adapted to being dark-adapted) that has been shown in previous work to detect the onset of AMD at least four years before it is clinically evident. Testing is completely non-invasive and can be performed by an unskilled operator with a minimum of patient burden. Our Phase I aim was to demonstrate feasibility by building a preliminary prototype diagnostic that could distinguish AMD patients from normal old adults in = 20 minutes.
This aim was easily achieved. A range of early to late AMD patients was readily discriminated from clinically normal old adults in = 20 minutes. The difference was both substantial (~100% dark adaptation impairment for AMD patients relative to normal old adults) and statistically significant (t = 6.02; p < 0.0001). Diagnostic sensitivity and specificity were 88% and 100%, respectively, with the degree of dark adaptation impairment tracking disease severity. Finally, there is promising pilot data for follow-on development of a commercial AMD screening test that can be completed in = 10 minutes. Our Phase II aim is to build a robust commercial prototype and evaluate the diagnostic sensitivity and specificity for detection of early AMD in a cross-sectional study of 200 patients (50% normal old adults; 50% having a range of early to intermediate AMD). Our goal is sensitivity and specificity = 90% with a test duration = 10 minutes. The University of Alabama at Birmingham and Johns Hopkins University will serve as clinical test sites. Age-related macular degeneration (AMD) is the leading cause of blindness for individuals in developed countries over 50 years old. It already affects more than 13 million people in the US, including one-third of those over 75, and the problem is expected to get worse as the population ages. Unfortunately, there is no simple means for early detection. A diagnostic for early AMD could aid in the development of early-stage treatments and identify individuals for intervention before the devastation of late-stage vision loss. ? ? ?
| Jackson, Gregory R; Scott, Ingrid U; Kim, Ivana K et al. (2014) Diagnostic sensitivity and specificity of dark adaptometry for detection of age-related macular degeneration. Invest Ophthalmol Vis Sci 55:1427-31 |
