Stereoacuity of Preschool Children with and without Vision Disorders

Abstract

Purpose To evaluate associations between stereoacuity and presence, type, and severity of vision disorders in Head Start preschool children and determine testability and levels of stereoacuity by age in children without vision disorders. Methods Stereoacuity of children aged 3 to 5 years (n = 2898) participating in the Vision in Preschoolers (VIP) Study was evaluated using the Stereo Smile II test during a comprehensive vision examination. This test uses a two-alternative forced-choice paradigm with four stereoacuity levels (480 to 60 seconds of arc). Children were classified by the presence (n = 871) or absence (n = 2027) of VIP Study–targeted vision disorders (amblyopia, strabismus, significant refractive error, or unexplained reduced visual acuity), including type and severity. Median stereoacuity between groups and among severity levels of vision disorders was compared using Wilcoxon rank sum and Kruskal-Wallis tests. Testability and stereoacuity levels were determined for children without VIP Study–targeted disorders overall and by age. Results Children with VIP Study–targeted vision disorders had significantly worse median stereoacuity than that of children without vision disorders (120 vs. 60 seconds of arc, p < 0.001). Children with the most severe vision disorders had worse stereoacuity than that of children with milder disorders (median 480 vs. 120 seconds of arc, p < 0.001). Among children without vision disorders, testability was 99.6% overall, increasing with age to 100% for 5-year-olds (p = 0.002). Most of the children without vision disorders (88%) had stereoacuity at the two best disparities (60 or 120 seconds of arc); the percentage increasing with age (82% for 3-, 89% for 4-, and 92% for 5-year-olds; p < 0.001). Conclusions The presence of any VIP Study–targeted vision disorder was associated with significantly worse stereoacuity in preschool children. Severe vision disorders were more likely associated with poorer stereopsis than milder or no vision disorders. Testability was excellent at all ages. These results support the validity of the Stereo Smile II for assessing random-dot stereoacuity in preschool children.

Uncorrected Hyperopia and Preschool Early Literacy

“…Correct identification was required for 4 of 4 or 4 of 5 trials at each level. Testing was administered as previously described 26 with the exception of adding 40″ and 30″ levels. Additional assessments included accommodative response at 33 cm (measured with the Grand Seiko Autorefractor [closest meridian to the target] and Monocular Estimation Method [MEM] dynamic retinoscopy [horizontal meridian] while children viewed a naturalistic target [detailed sticker of a popular cartoon character]).…”

Stereo vision and strabismus

“…At first sight, the advantage of offering more alternatives is that patients are less likely to succeed by guessing. Thus, four-alternative tests generally require fewer correct responses to pass a level: two out of three 19 or two out of two 20 correct responses, as compared with four out of five 21 for a two-alternative test. However, the logic behind this seems debatable.…”

The usefulness of the Retinomax autorefractor for childhood screening validated against a Danish preterm cohort examined at the age of 4 years

“…From a worldwide perspective, limits are set by the socioeconomic infrastructure, 6 and simpler settings are required. [7][8][9] The new generations of autorefractometers led to high expectations because they can be serviced by less specialized personnel. High testability in non-cycloplegic cohorts was thus reported in several centres using the hand-held Retinomax autorefractometer (Nikon Inc, Tokyo, Japan), and positive findings were subsequently evaluated against cycloplegic paediatric ophthalmic examinations.…”