Ocular motor function in relation to gross motor function in congenital and childhood myotonic dystrophy type 1.

PURPOSE: To assess ocular motor function in congenital and childhood myotonic dystrophy type 1 (DM1) and correlate the results with cytosine-thymine-guanine (CTG) repeat size, severity of the disease, myotonia and skeletal muscle function. METHODS: A cross-sectional investigation into strabismus, versions/ductions, saccades, smooth pursuit movements and ptosis was performed on 49 individuals with a confirmed diagnosis of DM1, all diagnosed at <18 years of age and with >40 CTG expansion repeats. The results were correlated with myotonia as well as Hammersmith motor ability scale (HMA). In addition, the ocular results were compared to results from an age and- sex-matched control group. RESULTS: Ocular motor abnormalities were seen in 82%; the most frequent findings were altered conjugate eye movements and 'pseudoptosis' while blepharoptosis was rare. Strabismus was most common in the severe congenital subgroup, with a frequency 14 times higher than in the control group. Positive correlations were seen between CTG repeat size and affected eyelids, and between myotonia and affected eyelids; both these findings were most prominent in the mild congenital group. CTG repeat size was also correlated with version/duction defects, and most obviously in the childhood group. Low HMA scores were associated with high occurrence of strabismus and version/duction defects. CONCLUSION: Abnormalities of ocular motor function are frequently present. CTG repeat size correlates positively with altered versions/ductions and eyelid pathology. Gross motor dysfunction correlates with strabismus and defect versions/ductions, and eyelid pathology indicates involvement of myotonia.

Visual function in congenital and childhood myotonic dystrophy type 1.

OBJECTIVE: To investigate visual function in a group of individuals with congenital and childhood myotonic dystrophy type 1 (DM1), to correlate the results to the size of the cytosine-thymine-guanine (CTG) repeat expansion and the onset form, and to compare the results with those of a control group. DESIGN: Cross-sectional study with age- and gender-matched control groups. PARTICIPANTS AND CONTROLS: Forty-nine individuals with severe and mild congenital and childhood DM1 and controls matched for age and gender. METHODS: The ophthalmologic examination included best-corrected visual acuity (BCVA), refraction, slit-lamp biomicroscopy, indirect ophthalmoscopy, and flash visual evoked potentials (VEPs). MAIN OUTCOME MEASURES: Visual acuity, refractive error, pathology of lens, fundus, and VEP pathologic features. RESULTS: The study shows a higher prevalence of low visual acuity, hyperopia, and astigmatism in the study population compared with the controls. The size of the CTG repeat expansion had an impact on BCVA in all subgroups with lower values in individuals with larger expansion size. In childhood DM1, individuals with high hyperopia and astigmatism had greater CTG repeat expansion size than those without. No true cataract was found. Subtle nonspecific fundus changes were present in addition to VEP pathology. CONCLUSIONS: Children and adolescents with DM1 have a variety of visual function pathologies, and DM1 has an impact on the developing visual system, necessitating early ophthalmologic assessment and follow-up.

Longterm visual prognosis in Usher syndrome types 1 and 2.

PURPOSE: To estimate the age at diagnosis of retinitis pigmentosa and to determine visual acuity deterioration, visual field impairment and the frequency of cataracts in Usher syndrome types 1 and 2. METHODS: We carried out a retrospective study of 328 affected subjects with Usher syndrome types 1 and 2. Study subjects were divided into seven different age groups by decade. Data were analysed using descriptive statistics, general linear model anova and survival analysis. RESULTS: Retinitis pigmentosa was diagnosed significantly earlier in subjects with Usher syndrome type 1 than in those with type 2. Visual acuity was significantly more impaired in affected subjects with Usher syndrome type 1 than in those with type 2 from 50 years of age onwards. Survival analysis revealed a significant difference in visual field loss (

Accommodation and the relationship to subjective symptoms with near work for young school children.

The aim of this work was to study the relation between subjective symptoms at near and ocular accommodation in terms of the amplitude of accommodation and the relative accommodation. A secondary aim was to discuss the diagnosis of accommodative insufficiency. The chosen cohort was examined on two occasions with 1.8 years in between. The first examination included 72 children, 43 boys (mean age 8.1 years, ranging from 5.8 to 9.8) and 29 girls (mean age 8.3 years, ranging from 6.2 to 10.0). The second examination included 59 of these children, 34 boys (mean age 9.9 years, ranging from 7.8 to 11.7) and 25 girls (mean age 10.1 ranging from 8.0 to 11.8). Subjective symptoms at near work (headache, asthenopia, floating text, facility problems) were recorded and the amplitude and the relative accommodation, both positive and negative, were measured. The result from the questionnaire showed that at the first examination more than one-third of the children (34.7%) reported at least one subjective symptom when doing near work and 42.4% at the second examination. No symptoms were found among children younger than 7.5 years, but for children between 7.5 and 10 years old at the first examination, the prevalence of at least one symptom was 47.2%. At the second examination, symptoms were reported also for the youngest children, i.e. from the age of 8 years. The discrimination ability for the amplitude of accommodation, both monocular and binocular, was significant. In the first examination the difference between the mean for the two groups (i.e. with and without at least one symptom) was around 2.00 D monocular and 3.00 D binocular. Corresponding figures from the second examination was a difference between the mean for the two groups of around 3.50 D monocular and nearly 4.00 D binocular. We suggest that accommodation measurements should be performed more routinely and regularly, maybe as screening, especially in children over 8 years of age.

The amplitude of accommodation in 6-10-year-old children - not as good as expected!

The aim of this study was to measure the amplitude of accommodation for junior level school children and to compare it with age-expected values. A junior level school in Göteborg, Sweden, was randomly chosen and the amplitude of accommodation among 76 children aged 6-10 years was examined using Donders' push-up method. The results showed lower amplitude than expected in a large group of children. Results also showed lower amplitude than previously reported for this age group, especially under monocular conditions, which revealed an average dioptric difference from the expected value of -3.60 dioptres (D) right eye (mean 12.40 D, median 12.00 D, S.D. 3.7 D) and -3.50 D left eye (mean 12.50 D, median 12.70 D, S.D. 3.8 D) (p < 0.001 for both eyes). Consequently, we conclude that it cannot be assumed that the amplitude of accommodation is in the expected amplitude range for all children of these ages.

Cerebral ventricular size in developing normal kittens measured by ultrasonography.

To evaluate the age of fontanelle closure of normal kittens and the size of their lateral ventricles, 50 ultrasonographic examinations using the bregmatic fontanelle as an acoustic window were made. Seven kittens, laboratory animals, were included in the study. To verify the location of the lateral ventricle, two of the kittens were sacrificed as neonates. In one of them ink was injected prior to autopsy into one lateral ventricle under sonographic guidance. In a longitudinal study of five of the kittens, the skull depth and the depth of the central part of the lateral ventricle reproduced in a longitudinal view could be measured up to the age of about 5 months. During that period, the skull depth increased from a median value of 1.95 cm (1.92-1.98) in a seven-day-old cat to 2.58 cm (2.52-2.59) in a 154-day-old cat, while the afore-mentioned ventricle values increased from 0.3 mm to 1.1 mm.

Visual acuity, amblyopia, and ocular pathology in 12- to 13-year-old children in Northern Mexico.

PURPOSE: The aim of this study was to establish visual acuity (VA) and the prevalence of amblyopia and other ocular disorders in a population of 12- to 13-year-old children in Mexico who have not been vision screened. METHODS: A total of 1,035 12- to 13-year-old children were examined in a field study. The examination included VA, stereopsis, cover testing, refractive retinoscopy, and examination of the red reflex and posterior pole. In cases with unexplained subnormal VA, visually evoked potential/visually evoked response was also performed. RESULTS: A >or=20/20 in at least one eye was found in 93% of the subjects. Bilateral VA

Ophthalmological abnormalities in children with cerebral white matter disorders.

The use of magnetic resonance imaging (MRI) in children with severe neurological impairment has defined a subgroup with increased T2-signals from cerebral white matter. The causes of white matter abnormalities are for the most part unknown, despite extensive investigation. Their clinical correlates and characteristics have still to be systematically analysed and described. We have compared clinical, ophthalmological and electro-ophthalmological findings in such children to delineate neurological and MRI patterns and have sought to correlate with the progression of disease. Clinical and electro-ophthalmological investigations were performed in 26 children with cerebral white matter abnormalities of unknown aetiology; 25 of the 26 children showed abnormalities, 23 clinical and 18 electro-ophthalmological. Optic nerve abnormalities, severe visual impairment and strabismus were the most common. Electro-ophthalmological abnormalities were increased latencies and abnormal waveform of the visual evoked potentials (VEP). Children with progressive disease all had abnormal VEP, whereas none of the ten children with a normal VEP deteriorated. We conclude that children with cerebral white matter abnormalities almost invariably had ophthalmological and often VEP abnormalities. Normal VEP was correlated with non-progressive disorder, as was hypoplasia or malformation of the papilla, whereas abnormal VEP were associated with progressive disease.

Screening for amblyopia and strabismus with the Lang II stereo card.

PURPOSE: To evaluate the effectiveness of the Lang II stereo card as a screening test for amblyopia and/or strabismus. METHODS: A total of 1046 children aged 12-13 years were examined in a field study in the Göteborg area, Sweden. In addition to the Lang II stereo card, the examination included visual acuity, cover testing, cycloplegic refraction, and inspection of the optical media and posterior pole. RESULTS: If every incorrect subject response was considered a reason for referral, the Lang II test would have correctly identified 82% (23 subjects) of the 28 children with manifest strabismus and 38% (11 subjects) of the 29 children with amblyopia. The test failed to refer 45% (21 subjects). Of all subjects referred, 44 (63%) were found to be ophthalmologically normal. CONCLUSIONS: The Lang II stereo card is neither a reliable nor an efficient method of screening for amblyopia and/or strabismus.