High levels of astigmatism exist among Native American peoples. While the prevalence of astigmatism is well studied, its developmental course and visual consequences are poorly understood. the goal of the proposed research is to establish the relation between astigmatism and visual development in native american children, and to determine the optimum strategy to mitigate detrimental effects of astigmatism in this population. A three-state research protocol is proposed: Stage 1: the prevalence of corneal, internal, and total astigmatism (as well as prevalence of reduced acuity and meridional amblyopia) will be examined in preschool children 6 months to 6 + years of age who are members of a Native American tribe (the Tohono O'Odham Nation) in which a high prevalence of astigmatism is present. Stage 2: spectacle correction will be provided based on guidelines resulting from a poll of 334 pediatric eye care practitioners. All children whose astigmatism, myopia, hyperopia, or anisometropia is of a magnitude that would be corrected by 99% of those polled will be classified as High risk for refractive amblyopia and will have spectacles prescribed. children whose astigmatism would be corrected by 50% to 98% of those polled will be in the Moderate Risk group; these children will be randomly assigned to receive spectacle correction or no spectacle correction. the remaining children will be in the Low Risk group and will not receive spectacles. Stage 3: Follow-up assessment of refractive effort and visual acuity will be performed at intervals of one, two and three years, to determine whether spectacle correction reduces the prevalence of below-normal best-corrected acuity. the primary analysis will be ca comparison of best-corrected acuity results from children who were randomized to spectacle correction with results from those who were randomized to no spectacle correction. It is hypothesized that the proportion of children with below normal acuity will be smaller in the group of children randomized to spectacles than in the group of children randomized to no spectacles. This study will show the effect of astigmatism on visual development and will determine whether correction of astigmatism during the preschool years prevents the development of refractive amblyopia, or produces an alteration in emmetropization.

National Institute of Health (NIH)
National Eye Institute (NEI)
Cooperative Clinical Research--Cooperative Agreements (U10)
Project #
Application #
Study Section
Special Emphasis Panel (ZEY1-VSN (01))
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of Arizona
Schools of Medicine
United States
Zip Code
Miller, Joseph M (2010) A handheld open-field infant keratometer (an american ophthalmological society thesis). Trans Am Ophthalmol Soc 108:77-95
Garvey, Katherine A; Dobson, Velma; Messer, Dawn H et al. (2010) Prevalence of strabismus among preschool, kindergarten, and first-grade Tohono O'odham children. Optometry 81:194-9
Harvey, Erin M (2009) Development and treatment of astigmatism-related amblyopia. Optom Vis Sci 86:634-9
Dobson, Velma; Clifford-Donaldson, Candice E; Green, Tina K et al. (2009) Optical treatment reduces amblyopia in astigmatic children who receive spectacles before kindergarten. Ophthalmology 116:1002-8
Dobson, Velma; Clifford-Donaldson, Candice E; Green, Tina K et al. (2009) Normative monocular visual acuity for early treatment diabetic retinopathy study charts in emmetropic children 5 to 12 years of age. Ophthalmology 116:1397-401
Miller, Joseph M (2009) Clinical applications of power vectors. Optom Vis Sci 86:599-602
Harvey, Erin M; Dobson, Velma; Miller, Joseph M et al. (2008) Changes in visual function following optical treatment of astigmatism-related amblyopia. Vision Res 48:773-87
Harvey, Erin M; Dobson, Velma; Miller, Joseph M et al. (2007) Amblyopia in astigmatic children: patterns of deficits. Vision Res 47:315-26
Mohan, K M; Miller, J M; Dobson, V et al. (2000) Inter-rater and intra-rater reliability in the interpretation of MTI Photoscreener photographs of Native American preschool children. Optom Vis Sci 77:473-82