PURPOSE. To define the critical period for susceptibility of human stereopsis to an anomalous binocular visual experience. METHODS. Random dot stereoacuity was measured in 152 children with a history of onset of eithe...PURPOSE. To define the critical period for susceptibility of human stereopsis to an anomalous binocular visual experience. METHODS. Random dot stereoacuity was measured in 152 children with a history of onset of either infantile or accommodative strabismus before5 years of age. In each of these populations and in the combined population, the critical periods for susceptibility of stereopsis are described using fourparameter developmental weighting functions. RESULTS. In children with infantile strabismus, the critical period for susceptibility of stereopsis begins at 2.4 months and peaks at4.3 months. In children with accommodative esotropia, the critical period for susceptibility of stereopsis begins at 10.8months and peaks at 20 months. When the data are combined across the two populations, the critical period begins soon after birth and peaks sharply at 3.5 months but shows continued susceptibility to at least4.6 years. CONCLUSIONS. An anomalous binocular visual experience during early infancy severely disrupts stereopsis, yet the critical period for susceptibility of stereopsis extends through late infancy and early childhood and continues to at least 4.6 years of age.展开更多
PURPOSE. Identification of risk factors for accommodative esotropia may help to determine which children with hyperopia may benefit from early spectacle correction or preventive therapy. METHODS. Participants in the f...PURPOSE. Identification of risk factors for accommodative esotropia may help to determine which children with hyperopia may benefit from early spectacle correction or preventive therapy. METHODS. Participants in the family history study were 95 consecutive patients, aged 18 to 60 months, with accommodative esotropia. Participants in the binocular sensory function study were a subgroup of 41 children enrolled in the family history study within 1 month of onset, while the esodeviation was still intermittent. Participants in the hypermetropia study were 345 consecutive patients, ages 12 months to 8 years, with refractive error of + 2.00 D or greater and no esodeviation before age 12 months. RESULTS. In the family history study, 23% of children with accommodative esotropia had an affected first- degree relative, and 91% had at least one affected relative. In the binocular sensory function study, random- dot stereoacuity was abnormal in41% of children, whereas an abnormal motion VEP, Worth4- dot, or positive4- PD base- out prism responses were present in4% or less of the children. In the hypermetropia study, patients with a mean spherical equivalent of<+ 3.00 D and significant anisometropia had a 7.8- fold increased risk for accommodative esotropia over nonanisometropic patients. CONCLUSIONS. A positive family history, subnormal random- dot stereopsis, and hypermetropic anisometropia each pose a significant risk for the development of accommodative esotropia. Assessment of these risk factors in conjunction with refractive screening should help to identify those children who are most likely to benefit from early spectacle correction or preventive treatment.展开更多
To develop a presentation protocol for the new Frisby-Davis 2 (FD2) distance stereoacuity test. Prospective data collection. Stereoacuity was tested monocularly and binocularly in 95 patients with a variety of strabis...To develop a presentation protocol for the new Frisby-Davis 2 (FD2) distance stereoacuity test. Prospective data collection. Stereoacuity was tested monocularly and binocularly in 95 patients with a variety of strabismic and nonstrabismic conditions, using the FD2, employing a modified staircase procedure. The Preschool Randot Stereoacu-ity test and the near Frisby test were used to determine whether a patient was stereoblind. Under monocular conditions, 35 (37% ) of 95 patients passed at least the largest disparity of the FD2 indicating a problem with monocular cues. The binocular protocol was then modified to include a monocular test phase. Using the new protocol, if a patient could achieve the same stereoacuity under monocular and binocular conditions, they were deemed to have no stereopsis. Testing 28 additional stereoblind patients using the new modified protocol revealed no false positives. The FD2 stereotest is a useful measure of distance stereoacuity, provided the presentation protocol accounts for monocular cues.展开更多
Functional improvements of binocular vision after strabismus surgery in adults are common but not well understood. In a prospective study, factors associated with stereoacuity outcome in patients with strabismus acqui...Functional improvements of binocular vision after strabismus surgery in adults are common but not well understood. In a prospective study, factors associated with stereoacuity outcome in patients with strabismus acquired following binocul ar vision maturation were investigated. Prospective data collection. Twenty-thr ee patients aged 14 to 85 years with acquired strabismus were enrolled. Random d ot stereoacuity was quantified using a battery of tests including the Randot Pre school Stereoacuity test, the Randot (version 2) shapes test, and the Randot But terfly test. Ninety-six percent of patients achieved measurable stereoacuity fo llowing successful eye realignment. Better median stereoacuity is achieved in pa tients with the following characteristics: ≤12 months of constant strabismus (6 0 vs 400 seconds of arc with > 12 months’strabismus, P < 0.001); a presurgical capacity for fine to moderate stereopsis (60 vs 400 seconds of arc with coarse o r no measurable stereopsis, P < 0.005); a presurgical capacity for macular fusio n (60 vs 400 seconds of arc with no measurable macular fusion capacity, P < 0.00 1); and postsurgical orthotropia (100 seconds of arc) or intermittent orthotropi a (100 seconds of arc vs 2000 seconds of arc with 5 to 8 prism diopters (PD) of postsurgical residual strabismus, P < 0.05). Surgical correction of acquired str abismus is associated with recovery of stereopsis. Factors associated with stere oacuity outcomes include duration of strabismus and presurgical binocular vision capacity. A postsurgical correction of orthotropia or intermittent orthotropia supports better stereoacuity than a larger residual angle of strabismus subtendi ng up to 8 PD of deviation.展开更多
文摘PURPOSE. To define the critical period for susceptibility of human stereopsis to an anomalous binocular visual experience. METHODS. Random dot stereoacuity was measured in 152 children with a history of onset of either infantile or accommodative strabismus before5 years of age. In each of these populations and in the combined population, the critical periods for susceptibility of stereopsis are described using fourparameter developmental weighting functions. RESULTS. In children with infantile strabismus, the critical period for susceptibility of stereopsis begins at 2.4 months and peaks at4.3 months. In children with accommodative esotropia, the critical period for susceptibility of stereopsis begins at 10.8months and peaks at 20 months. When the data are combined across the two populations, the critical period begins soon after birth and peaks sharply at 3.5 months but shows continued susceptibility to at least4.6 years. CONCLUSIONS. An anomalous binocular visual experience during early infancy severely disrupts stereopsis, yet the critical period for susceptibility of stereopsis extends through late infancy and early childhood and continues to at least 4.6 years of age.
文摘PURPOSE. Identification of risk factors for accommodative esotropia may help to determine which children with hyperopia may benefit from early spectacle correction or preventive therapy. METHODS. Participants in the family history study were 95 consecutive patients, aged 18 to 60 months, with accommodative esotropia. Participants in the binocular sensory function study were a subgroup of 41 children enrolled in the family history study within 1 month of onset, while the esodeviation was still intermittent. Participants in the hypermetropia study were 345 consecutive patients, ages 12 months to 8 years, with refractive error of + 2.00 D or greater and no esodeviation before age 12 months. RESULTS. In the family history study, 23% of children with accommodative esotropia had an affected first- degree relative, and 91% had at least one affected relative. In the binocular sensory function study, random- dot stereoacuity was abnormal in41% of children, whereas an abnormal motion VEP, Worth4- dot, or positive4- PD base- out prism responses were present in4% or less of the children. In the hypermetropia study, patients with a mean spherical equivalent of<+ 3.00 D and significant anisometropia had a 7.8- fold increased risk for accommodative esotropia over nonanisometropic patients. CONCLUSIONS. A positive family history, subnormal random- dot stereopsis, and hypermetropic anisometropia each pose a significant risk for the development of accommodative esotropia. Assessment of these risk factors in conjunction with refractive screening should help to identify those children who are most likely to benefit from early spectacle correction or preventive treatment.
文摘To develop a presentation protocol for the new Frisby-Davis 2 (FD2) distance stereoacuity test. Prospective data collection. Stereoacuity was tested monocularly and binocularly in 95 patients with a variety of strabismic and nonstrabismic conditions, using the FD2, employing a modified staircase procedure. The Preschool Randot Stereoacu-ity test and the near Frisby test were used to determine whether a patient was stereoblind. Under monocular conditions, 35 (37% ) of 95 patients passed at least the largest disparity of the FD2 indicating a problem with monocular cues. The binocular protocol was then modified to include a monocular test phase. Using the new protocol, if a patient could achieve the same stereoacuity under monocular and binocular conditions, they were deemed to have no stereopsis. Testing 28 additional stereoblind patients using the new modified protocol revealed no false positives. The FD2 stereotest is a useful measure of distance stereoacuity, provided the presentation protocol accounts for monocular cues.
文摘Functional improvements of binocular vision after strabismus surgery in adults are common but not well understood. In a prospective study, factors associated with stereoacuity outcome in patients with strabismus acquired following binocul ar vision maturation were investigated. Prospective data collection. Twenty-thr ee patients aged 14 to 85 years with acquired strabismus were enrolled. Random d ot stereoacuity was quantified using a battery of tests including the Randot Pre school Stereoacuity test, the Randot (version 2) shapes test, and the Randot But terfly test. Ninety-six percent of patients achieved measurable stereoacuity fo llowing successful eye realignment. Better median stereoacuity is achieved in pa tients with the following characteristics: ≤12 months of constant strabismus (6 0 vs 400 seconds of arc with > 12 months’strabismus, P < 0.001); a presurgical capacity for fine to moderate stereopsis (60 vs 400 seconds of arc with coarse o r no measurable stereopsis, P < 0.005); a presurgical capacity for macular fusio n (60 vs 400 seconds of arc with no measurable macular fusion capacity, P < 0.00 1); and postsurgical orthotropia (100 seconds of arc) or intermittent orthotropi a (100 seconds of arc vs 2000 seconds of arc with 5 to 8 prism diopters (PD) of postsurgical residual strabismus, P < 0.05). Surgical correction of acquired str abismus is associated with recovery of stereopsis. Factors associated with stere oacuity outcomes include duration of strabismus and presurgical binocular vision capacity. A postsurgical correction of orthotropia or intermittent orthotropia supports better stereoacuity than a larger residual angle of strabismus subtendi ng up to 8 PD of deviation.
