Esterman binocular scoring in amblyopia.

The Esterman binocular visual field test was performed on 24 amblyopic subjects and 10 normal subjects. No correlation was found between the evaluated clinical parameters and Esterman scores in the patients with amblyopia. The Esterman score may not properly reflect the actual binocular disability in amblyopia.

Factors influencing the outcome of strabismus surgery in patients with exotropia.

PURPOSE: To determine the factors associated with favorable and less favorable outcomes in strabismus surgery for treatment of exotropia and to show the factors influencing the efficacy of the surgical procedure. METHODS: Case files of 225 patients with a diagnosis of primary exotropia were evaluated. Information about patient age at onset of deviation, patient age at surgery, interval between onset and surgery, preoperative deviation, refractive errors, degree of anisometropia, visual acuity, presence of amblyopia, presence of an A- or a V-pattern, amount of surgery performed, type of exotropia (intermittent or constant), and existence of binocular single vision before surgery were obtained and evaluated using multiple regression analysis. RESULTS: Preoperative deviation and refractive errors were proved to be significant factors influencing a favorable outcome in patients with surgically treated exotropia (r(2) = 0.12, P <.001, and r(2) = 0.07, P <.001 respectively). Preoperative deviation, amount of surgery performed, and refractive errors shifting toward myopia significantly influenced the efficacy of the surgery performed (r(2) = 0.31, 0.06, and 0.025, respectively). CONCLUSION: Special care should be paid to refractive errors in patients with exotropia before determining the amount of surgical intervention.

Evaluation of the functions of the parvocellular and magnocellular pathways in strabismic amblyopia.

PURPOSE: To evaluate the functions of the magnocellular and parvocellular pathways in strabismic amblyopia. METHODS: Visual evoked potentials produced by achromatic and chromatic stimuli in 14 children with strabismic amblyopia were compared with those in 14 age-matched control subjects. The achromatic sine-wave grating with low spatial frequency was used to stimulate the magnocellular pathway, whereas the parvocellular pathway was stimulated by the chromatic sine-wave grating (isoluminant red-green) with low and high spatial frequencies. RESULTS: When the achromatic stimuli with low spatial frequency were used, the latencies of the N1 and P1 components and the amplitude of the N1-P1 complex were similar in the children with strabismic amblyopia and the control subjects. There also were no differences between the amblyopic and non-amblyopic eyes of the children with strabismic amblyopia. When chromatic stimuli with low and high spatial frequencies were used, the latencies of the N1 and P1 components were significantly longer and the amplitude of the N1-P1 complex was significantly smaller in the children with strabismic amblyopia than in the control group. When the amblyopic and non-amblyopic eyes of the children with strabismic amblyopia were compared, the latencies of the N1 and P1 components were longer and the amplitude of the N1-P1 complex was smaller in the amblyopic eyes. CONCLUSION: In strabismic amblyopia, the cells in the parvocellular pathway may be more involved, whereas the magnocellular pathway may be relatively spared.