Abstract
Recent progress in understanding the pathogenesis of retinal degenerative diseases, such as age-related or juvenile macular degeneration, has led to the exciting possibility of treatment trials for these diseases. It is well documented that early detection of eye diseases or early detection of the change of disease status is crucial to successful treatment. Furthermore, the effectiveness of any treatment for eye diseases must ultimately be assessed in terms of its ability to preserve visual function. Hence, there is an increasing demand for new visual function tests that are more sensitivity than current standard tests such as visual acuity in evaluating vision loss in macular degeneration. Given that the damage from macular degeneration is inhomogeneous across the macula and the subretinal deposits do not always affect visual acuity, we hypothesized that it would be more difficult for patients with macular degeneration to perform distortion detection tasks requiring global visual integration over a larger retinal area than to perform a localized test such as visual acuity. We have developed a new shape discrimination paradigm to test this hypothesis, and have shown that shape discrimination sensitivity is significantly reduced in patients with macular degeneration, even though they may still retain normal visual acuity. We are evaluating the efficacy of the shape discrimination test, together with other functional tests and retinal imaging methods, in assisting early detection, monitoring the progression, and evaluating treatment outcomes of macular degeneration.