The incidence and clinical characteristics of adult-onset convergence insufficiency.

OBJECTIVE: The purpose of this study was to describe the clinical characteristics and natural history of convergence insufficiency (CI) in a population-based cohort of adults. DESIGN: Retrospectively reviewed population-based cohort. PARTICIPANTS: Adult (age ≥19 years) residents of Olmsted County, Minnesota. METHODS: The medical records of all adults diagnosed with CI over a 20-year period were reviewed retrospectively. MAIN OUTCOME MEASURES: Clinical characteristics and outcomes for adult-onset CI. RESULTS: A total of 118 adults (annual incidence, 8.44 per 100 000 patients older than 19 years) were diagnosed with CI during the 20-year period, constituting 15.7% of all forms of adult-onset strabismus observed in this population. The median age at diagnosis was 68.5 years (range, 21.7-97.1 years), and 68 (57.6%) were female. The mean initial exodeviation at near was 14.1 prism diopters (PD; range, 1-30 PD) and 1.7 PD (range, 0-10 PD) at distance. The Kaplan-Meier rate of exotropia increasing over time by 7 PD or more at near was 4.2% at 5 years, 13.5% at 10 years, and 24.4% at 20 years. Approximately 88% were managed with prisms, whereas less than 5% underwent surgical correction. CONCLUSIONS: Adult-onset CI included approximately 1 in 6 adults who were newly diagnosed with strabismus in this 20-year cohort. There was a significant increase in incidence with increasing age. Nearly one-fourth had an increase of their near exodeviation of at least 7 PD by 20 years after their diagnosis, and most patients were managed conservatively.

Relative roles of luminance and fixation in inducing dissociated vertical divergence.

PURPOSE: We evaluated the roles of luminance and fixation in the pathophysiology of dissociated vertical divergence (DVD). METHODS: Vertical eye position was measured in 6 subjects with DVD (ages 11-47 years, 5 females) and 6 controls (ages 16-40 years, 5 females) using video-oculography (VOG) under conditions of change in fixation and luminance. RESULTS: Subjects with DVD showed the following VOG responses. When fixation was precluded with a translucent filter and bright light was shone into one eye to produce a marked binocular luminance disparity, we found some subjects had a small induced vertical divergence causing the illuminated eye to be lower than the nonilluminated eye (mean -1.6° ± 1.5°, P = 0.06 compared to no vertical divergence using the signed rank test). When fixation was precluded with a translucent filter, while alternate occlusion produced a mild binocular luminance disparity, we found a smaller vertical divergence of the eyes that was not statistically significant (1.2° ± 2.1°, P = 0.3). When alternate occlusion produced reversal of monocular fixation in the dark (with essentially no change in peripheral luminance disparity), there was a significant vertical divergence movement causing the covered eye to be relatively higher than the uncovered eye (7.2° ± 3.1°, P = 0.03). The amplitude of this vertical divergence was similar to that measured under conditions of alternate occlusion in a lighted room (where there also was a significant average relative upward movement of the covered eye of 8.1° ± 2.9°, P = 0.03). Control subjects showed no vertical divergence under any testing conditions. CONCLUSIONS: Dissociated vertical divergence is mediated primarily by changes in fixation and only to a minor degree by binocular luminance disparity.

Congenital ocular motor apraxia with wheel-rolling ocular torsion-a neurodiagnostic phenotype of Joubert syndrome.

Joubert syndrome is a multisystem disorder that is associated with a constellation of cyclic ocular motor disturbances. We describe 2 children with congenital ocular motor apraxia who displayed wheel-rolling torsional eye movements and tonic alternating cyclodeviations of the eyes on retinal examination as a neurodiagnostic phenotype of Joubert syndrome.