The natural course of intermittent exotropia and the factors affecting its control has been unclear. We aim to report the natural course of our cohort of 117 Chinese children with intermittent exotropia and to identify baseline parameters that may have predictive value in the control deterioration of the disease. The visual acuity, spherical equivalent, compliance to orthoptic exercise, angle o...

Purpose: The aims of this study were to compare fusional vergence measurements between orthophoria, esophoria and exophoria, and to determine the strength of correlations between fusional convergence and divergence and angle of deviation. Methods and materials: A cross-sectional study was performed in children with best-corrected visual acuity of 0.0 LogMAR in either eye, compensated heterophor...

Two possible explanations are presented for the mechanism which limits the maximum fusional vergence response. An experimental paradigm is developed to differentiate between these alternatives. Experimental results indicate that the blur generally associated with strong fusional effort is due to convergence accommodation "overdrive." Th important theoretical and clinical implications of this fi...

A patient with uncorrected antimetropia was found to attain motor fusion through blinking. Although this patient was also able to attain motor fusion through saccadic vergence and slow fusional vergence, he usually relied on blink vergence. In this patient, blink vergence was an efficient alternative to slow fusional vergence.

purpose: the goal of this study was to compare differences in the mean heterophoria and fusional amplitudes before and after photorefractive keratectomy (prk) for myopia. methods: in a prospective controlled study, myopic patients were treated with aspheric and wavefront-guided (personalized) prk. the manifest refraction, visual acuity, fusional amplitudes and heterophoria were evaluated preope...

Purpose: To compare fusional vergence amplitudes in patients with symptomatic and asymptomatic near exophoria Methods: This cross-sectional study included 102 patients with near exophoria and asthenopia and 86 with asymptomatic near exophoria, all of whom were aged 15-35 years and had best corrected far visual acuity better than 20/25. Far and near fusional vergence amplitudes were evaluated in...

IT is generally accepted that nearly all patients with fixed small-angle convergent strabismus and bilateral central fixation show harmonious anomalous retinal correspondence (h.a.r.c.) when examined in normal surroundings under nondissociating test conditions (Bagolini's striated glasses) (Bagolini and Tittarelli, 1960; Pasino and Maraini, 1962). H.a.r.c. has been shown to adapt itself quite e...

The stability of binocular vision depends on good fusional amplitudes. These amplitudes are the result of a reflex arc, the sensory stimulus being caused by the images of the object of regard falling off one fovea. If this image falls outside Panum's area, diplopia will result. The motor response involves a movement of one or both eyes to maintain fusion and avoid diplopia. The afferent sensory...

Humans have two, frontally placed eyes and during reading oculomotor and sensory processes are needed to combine the two inputs into a unified percept of the text. Generally, slight vergence errors, i.e., fixation disparities, occur but do not cause double vision since disparate retinal inputs fall into Panum's fusional area, that is, a range of disparity wherein sensory fusion of the two retin...