Evaluation of vertical deviations secondary to other causes.

Distinguishing the cause of a vertical deviation can be important for management. When surgery is being considered, it is also critical to distinguish a true hypertropia from a dissociated vertical deviation (DVD). This paper reviews the clinical manifestations of DVD, true hypertropia, and primary oblique muscle dysfunction.

Comparison of primary position measurements and abduction deficit between type 1 Duane syndrome and sixth cranial nerve palsy.

BACKGROUND: Unilateral Duane retraction syndrome type 1 (DRS-I) and unilateral sixth nerve palsy (6NP) present with limitation of abduction, incomitant esotropia, and frequently, a compensatory head turn. The purpose of this study was to compare the mean primary position measurement and to correlate this with the abduction deficit to determine if these measurements may be used to differentiate between the 2 conditions when other clinical signs of DRS-I (globe retraction, changes in lid fissure height, and upshoots/downshoots) are subtle. METHODS: A database search of patients examined over a 5-year period revealed 69 cases of DRS-I and 62 cases of unilateral 6NP. Primary position measurements both at distance and near and limitation of abduction on version testing were recorded and compared. RESULTS: Mean abduction deficit was -3.5 ± 0.1 for DRS-I and -2.6 ± 0.2 for 6NP (P = 0.0004). Mean esotropia at near was 8.4 ± 1.1 prism diopters (PD) for DRS-I and 27.2 ± 2.4 PD for 6NP (P < 0.0001). Mean esotropia at distance was 10.3 ± 1.3 PD for DRS-I and 36.4 ± 2.4 PD for 6NP (P < 0.0001). The mean distance-near disparity for DRS-I was 1.94 ± 0.62 PD and 9.19 ± 1.28 PD for 6NP (P < 0.0001). The age-group of ≤2 years consisted of 23 DRS-I and only 2 6NP cases. The age-group between >2 years and <18 years had 41 DRS-I and 16 6NP cases, respectively. Finally, the age-group of ≥18 years had only 5 DRS-I and 44 6NP cases (P < 0.0001). CONCLUSION: Patients with DRS-I showed greater abduction deficit yet significantly less esotropia in primary position than those with 6NP. Patients with 6NP were more likely to have a significant distance-near disparity. In addition, patients with DRS-I tended to be younger than those with 6NP. This report documents that DRS-I and 6NP can be differentiated based on magnitude of primary position esotropia, comparison of primary position esotropia with severity of abduction deficit, distance-near disparity, and patient age.

Cerebral Palsy for the Pediatric Eye Care Team Part III: Diagnosis and Management of Associated Visual and Sensory Disorders.

INTRODUCTION: Cerebral palsy (CP) is a term used to describe a spectrum of deficits of muscle tone and posture resulting from damage to the developing nervous system. Though considered a motor disorder, CP can be associated with disorders of the sensory visual pathway. This paper, the final in a series of three articles, will present frequency, diagnosis, and management of the visual and binocular vision deficits associated with CP. Topics for discussion will include the prevalence and etiology of decreased acuity, the effect of CP on sensory and motor fusion, and the response to treatment for these sensory deficits. METHODS: A retrospective chart review of all cases of cerebral palsy referred to the St. Louis Children's Hospital Eye Center was done. Detailed data on the sensory and motor deficits documented in these children was collected. Also recorded was the management strategy and response to treatment. RESULTS: Of the 131 cases reviewed (mean age 5.2 years at presentation), 46% had decreased vision in at least one eye due to amblyopia (24%), optic nerve abnormality (16%), cortical visual impairment (14%), or a combination. Forty-nine (37%) had significant refractive error. Sixty-four percent of those with significant refractive error responded to spectacle correction. Forty-three percent of those with amblyopia responded to conventional therapies. Of the nonstrabismic patients, 89% demonstrated sensory fusion, 90% had stereopsis, and 91% had motor fusion. No patient lacking fusion or stereopsis prior to strabismus surgery gained these abilities with realignment of the eyes. CONCLUSION: While children with CP are capable of age-appropriate acuity and binocular vision, they are at increased risk for sensory visual deficits. These deficits are not the direct result of CP itself, but either share a common underlying cause, or occur as sequelae to the strabismus that is prevalent in CP. Most importantly, some sensory deficits may respond to standard treatment methods.