A Randomised Controlled Trial of Treatment for Post-Stroke Homonymous Hemianopia: Screening and Recruitment.

The authors report the screening process and recruitment figures for the VISION (Visual Impairment in Stroke; Intervention Or Not) trial. This is a prospective, randomised, single-blinded, three-arm controlled trial in 14 UK acute hospital stroke units. Stroke teams identified stroke survivors suspected as having homonymous hemianopia. Interventions included Fresnel prisms versus visual search training versus standard care (information only). Primary outcome was change in visual field assessment from baseline to 26 weeks. Secondary measures included change in quality-of-life questionnaires. Recruitment opened in May 2011. A total of 1171 patients were screened by the local principal investigators. Of 1171 patients, 178 (15.2%) were eligible for recruitment: 87 patients (7.4%) provided consent and were recruited; 91 patients (7.8%) did not provide consent, and 993 of 1171 patients (84.8%) failed to meet the eligibility criteria. Almost half were excluded due to complete/partial recovery of hemianopia (43.6%; n = 511). The most common ineligibility reason was recovery of hemianopia. When designing future trials in this area, changes in eligibility criteria/outcome selection to allow more patients to be recruited should be considered, e.g., less stringent levels of visual acuity/refractive error. Alternative outcomes measurable in the home environment, rather than requiring hospital attendance for follow-up, could facilitate increased recruitment.

What are the effects of metopic synostosis on visual function?

Metopic synostosis is a premature fusion of the metopic cranial suture. Small case studies into the effects on vision have suggested that there is a raised incidence of astigmatic refractive error with increased risk of failure to develop normal vision if reconstructive surgery is delayed beyond 7 months of age. The aim of this study was to look at a much larger group of patients to give more statistical significance on the incidence of significant refractive error and strabismus in cases of metopic synostosis and compare this with that known for the general population of children at a similar age. A secondary objective was to look at the age at surgery and the visual outcome. A retrospective analysis of case notes was carried out for 64 children with a confirmed diagnosis of metopic synostosis attending the Oxford Craniofacial Unit. Twenty children (31%) were found to have a visual problem, with 18 needing glasses to correct a refractive error and 10 having strabismus. The nature of refractive error was generally hypermetropia, in some cases combined with low astigmatism (1.5 diopters [D] or less). Only 1 child was recorded as having more than 1.5 D of astigmatism. The age at surgery did not seem to influence visual outcome. The incidence of significant refractive error requiring correction and strabismus across the metopic group (31%) was higher than that found in the general population of children at a similar age (5%-11%). This reinforces the importance of orthoptic/ophthalmic surveillance in metopic synostosis.

Strabismus in unicoronal synostosis: ipsilateral or contralateral?

Unicoronal synostosis is a premature fusion of one of the coronal sutures and is thought to carry an increased prevalence for strabismus. Studies suggest the nature of the strabismus to be a hypertropia occurring ipsilateral to the fused coronal suture. The aim of this study is to investigate the laterality of strabismus in unicoronal synostosis and report on ocular motility and refractive findings in a large, unbiased sample group. A retrospective case study analysis was carried out on 59 patients with a confirmed diagnosis of unicoronal synostosis referred to the Oxford Craniofacial Unit over a 14 year period. Manifest strabismus in the primary position was found in 34 (57.6%) cases. In 19 (55.9%) cases, this occurred contralateral to the fused suture, and in 9 (26.5%) cases, strabismus was on the ipsilateral side. Six had alternating strabismus. These results are contrary with apparent findings in the literature but are not statistically significant (P = 0.0872) for strabismus occurring more frequently on the nonsynostotic side. Esotropia with a vertical component was most common, found in 61% of all cases with strabismus. Apparent inferior oblique overaction was found in 30 of the 59 (50.8%) cases, with this occurring bilaterally in 14 cases. Significant refractive error was found in 46% of all cases, most of which showed anisometropia and astigmatism that occurred more frequently on the contralateral, nonsynostotic side (P = 0.0106). All cases of unicoronal synostosis with a mutation of the FGFR2 or FGFR3 gene had manifest strabismus. Manifest strabismus was found in 57.6% of cases reviewed, but this was found to be no more likely to occur on the side contralateral or ipsilateral to the fused suture (P = 0.0872). Anisometropia and astigmatism were found more frequently in the eye contralateral to the fused suture.