Amblyopia Essays -- Medicine Medical Eye Papers

Amblyopia This paper provides a brief description of amblyopia and discusses current research regarding the motion pathway in individuals with amblyopia. Amblyopia is a condition in which visual acuity in one eye is greatly reduced. It is caused by lack of stimulation or disuse during visual development (Rose, 1998). Because the eye is not fully developed at birth (Jarvis, 1992, as cited in Rose, 1998), infants need stimulation to complete the visual neural pathway. When one or both eyes are inhibited, for example due to misalignment of one eye (strabismus) or a large difference in refractive power between two eyes (anisometropia), the neural pathway for the inhibited eye develops abnormally, or does not develop at all. At approximately six years of age eye development is complete (Stager, 1990, as cited in Rose, 1998). Before visual development is complete amblyopia can be treated. If it is caught and treated at an early age, normal vision can be preserved (Rose, 1998). There are several types of amblyopia. Researchers must be aware of the various types of amblyopia because the effects for each are not always consistent. Strabismic amblyopia is caused when the two eyes are out of alignment due to weak musculature. Anisometropic amblyopia is a result of a large difference in refractive power of an individual's eyes. Another form of amblyopia results when visual information does not reach the retina. This is called stimulus deprivation amblyopia. Meridional amblyopia is a result of the diffused images caused by astigmatism. Researchers often discover that there are differences between groups of amblyopes based on type. For example, Levi and his colleagues (1994) discovered differences in vernier acuity between anisomet... ...9-1944. Hess, R. F., & Anderson, S. J. (1993). Motion sensitivity and spatial undersampling in amblyopia. Vision Research, 33, 881-896. Hess, R. F., Demanins, R., & Bex, P. J. (1997). A reduced motion aftereffect in strabismic amblyopia. Vision Research, 37, 1303-1311. Kubova, Z., Miroslav, K., Juran, J., & Blakemore, C. (1996). Is the motion system relatively spared in amblyopia? Evidence from cortical evoked responses. Vision Research, 36, 181-190. Levi, D. M., Klein, S. A., & Wang, H. (1994). Amblyopic and peripheral vernier acuity: a test-pedestal approach. Vision Research, 34, 3265-3292. Levi, D. M., & Polat, U. (1996). Neural plasticity in adults with amblyopia [Abstract]. Proceedings of the National Academy of Sciences of the United States, 93, 6830. Rose, S. E. (1998). Amblyopia: the silent thief. The Journal of School Health, 68, 2, 76-79.