Abstract
Abstract: :
Purpose: To evaluate the ability of preschool children to have threshold visual acuity assessed using a standardized, PC–based letter test. Methods: Participants were 1,195 3½– to 5–year–old Head Start children enrolled in the Vision In Preschoolers (VIP) Study. Monocular visual acuity was assessed by licensed eye care professionals (optometrists and pediatric ophthalmologists), using the Electronic Visual Acuity tester (EVA) which uses the letters H, O, T, and V with a crowded surround. Results: Overall, 99.1% of children passed the training. Among those who passed the training, 99.6% completed the binocular pretest at 3 m, and 97.6% of those passing both the training and the pretest completed monocular threshold visual acuity testing of each eye. Testability increased with age for training (p=0.03), pretesting (p=0.04), and acuity testing (p=0.07). Overall, 93.3% of 3½–year–olds, 96.7% of 4–year–olds, and 98.8% of 5–year–olds completed training, pretesting and monocular acuity testing of each eye. Conclusions: Using the PC–based EVA system, nearly all 3½– to 5–year–old children can complete monocular threshold acuity testing of each eye using standard letter optotypes.