Myopia in young patients with type 1 diabetes mellitus.

INTRODUCTION: This study aimed to evaluate the proportion of young patients with type 1 diabetes mellitus (T1DM) who have myopia, as well as the risk factors associated with myopia in this group. METHODS: In this cross-sectional study, patients aged < 21 years with T1DM for ≥ 1 year underwent a comprehensive eye examination. Presence of parental myopia, and average hours of near-work and outdoor activity were estimated using a questionnaire. Annualised glycosylated haemoglobin (HbA1c), defined as the mean of the last three HbA1c readings taken over the last year, was calculated. Multivariate analysis using genetic, environmental and diabetes-related factors was done to evaluate risk factors associated with myopia. RESULTS: Of the 146 patients (mean age 12.5 ± 3.6 years) recruited, 66.4% were Chinese and 57.5% were female. Myopia (i.e. spherical equivalent [SE] of -0.50 D or worse) was present in 96 (65.8%) patients. The proportion of patients with myopia increased from 25.0% and 53.6% in those aged < 7.0 years and 7.0-9.9 years, respectively, to 59.2% and 78.4% in those aged 10.0-11.9 years and ≥ 12.0 years, respectively. Higher levels of SE were associated with lower parental myopia (p = 0.024) and higher annualised HbA1c (p = 0.011). CONCLUSION: Compared to the background population, the proportion of myopia in young patients with T1DM was higher in those aged < 10 years but similar in the older age group. Myopia was associated with a history of parental myopia. Environmental risk factors and poor glycaemic control were not related to higher myopia risk.

Risk factors for strabismus and amblyopia in young Singapore Chinese children.

PURPOSE: To determine the risk factors for strabismus and amblyopia in young Singapore Chinese children. METHODS: A total of 3009 children were recruited for the population-based cross-sectional Strabismus, Amblyopia and Refractive Error in Singaporean Preschoolers Study (STARS). Strabismus was defined as any tropia identified on cover test. Visual acuity was measured in children aged 30-72 months with a logMAR chart where possible and the Sheridan-Gardiner test if not. Amblyopia was defined based on visual acuity and refractive error or presence of strabismus or past/present visual axis obstruction. Parents completed questionnaires on family, prenatal and birth histories. RESULTS: Our study showed that 24 children aged 6-72 months (1.2%) had strabismus (20 with exotropia), and 20 children aged 30-72 months (0.8%) were amblyopic. After multivariate analysis, strabismus was associated with astigmatism ≥1.00 diopter (D; p = 0.03), amblyopia (p = 0.003), a sibling with strabismus (p < 0.001), and families with lower parental education (p = 0.04). In addition to strabismus, amblyopia was associated with anisometropia ≥1.00 D (p < 0.001) and astigmatism ≥1.00 D (p < 0.001). No association was noted between either strabismus or amblyopia and prematurity, maternal age or smoking. CONCLUSION: This study highlights the importance of family history in strabismus, and the close associations between refractive error and strabismus with amblyopia. These factors play a more important role in young Singapore Chinese children.

Prevalence of amblyopia and strabismus in young singaporean chinese children.

PURPOSE. To determine the prevalence of amblyopia and strabismus in young Singaporean Chinese children. METHODS. Enrolled in the study were 3009 Singaporean children, aged 6 to 72 months. All underwent complete eye examinations and cycloplegic refraction. Visual acuity (VA) was measured with a logMAR chart when possible and the Sheridan-Gardner test when not. Strabismus was defined as any manifest tropia. Unilateral amblyopia was defined as a 2-line difference between eyes with VA < 20/30 in the worse eye and with coexisting anisometropia (> or =1.00 D for hyperopia, > or =3.00 D for myopia, and > or =1.50 D for astigmatism), strabismus, or past or present visual axis obstruction. Bilateral amblyopia was defined as VA in both eyes <20/40 (in children 48-72 months) and <20/50 (<48 months), with coexisting hyperopia > or =4.00 D, myopia < or = -6.00 D, and astigmatism > or =2.50 D, or past or present visual axis obstruction. RESULTS. The amblyopia prevalence in children aged 30 to 72 months was 1.19% (95% confidence interval [CI], 0.73-1.83) with no age (P = 0.37) or sex (P = 0.22) differences. Unilateral amblyopia (0.83%) was twice as frequent as bilateral amblyopia (0.36%). The most frequent causes of amblyopia were refractive error (85%) and strabismus (15%); anisometropic astigmatism >1.50 D (42%) and isometropic astigmatism >2.50 D (29%) were frequent refractive errors. The prevalence of strabismus in children aged 6 to 72 months was 0.80% (95% CI, 0.51-1.19), with no sex (P = 0.52) or age (P = 0.08) effects. The exotropia-esotropia ratio was 7:1, with most exotropia being intermittent (63%). Of children with amblyopia, 15.0% had strabismus, whereas 12.5% of children with strabismus had amblyopia. CONCLUSIONS. The prevalence of amblyopia was similar, whereas the prevalence of strabismus was lower than in other populations.

Formal synthesis of (+)-SCH 351448: the Prins cyclization approach.

The formal synthesis of (+)-SCH 351448 has been accomplished with the catalytic Prins cyclization strategy, yielding the monomeric unit as a single isomer.

Stannane-free chemoselective hydrodehalogenation of 4-halotetrahydropyrans: scope and application to natural product synthesis.

A stannane-free hydrodehalogenation of 4-halotetrahydropyran under very mild conditions has been developed. This methodology allows selective one-pot dehalogenation and/or debenzylation depending on the type of halide-substrate used. The applicability of this methodology is well demonstrated in the synthesis of a key intermediate toward the enantioselective synthesis of (+)-SCH 351448.

Atropine for the treatment of childhood myopia.

PURPOSE: To evaluate the efficacy and safety of topical atropine, a nonselective muscarinic antagonist, in slowing the progression of myopia and ocular axial elongation in Asian children. DESIGN: Parallel-group, placebo-controlled, randomized, double-masked study. PARTICIPANTS: Four hundred children aged 6 to 12 years with refractive error of spherical equivalent -1.00 to -6.00 diopters (D) and astigmatism of -1.50 D or less. INTERVENTION: Participants were assigned with equal probability to receive either 1% atropine or vehicle eye drops once nightly for 2 years. Only 1 eye of each subject was chosen through randomization for treatment. MAIN OUTCOME MEASURES: The main efficacy outcome measures were change in spherical equivalent refraction as measured by cycloplegic autorefraction and change in ocular axial length as measured by ultrasonography. The primary safety outcome measure was the occurrence of adverse events. RESULTS: Three hundred forty-six (86.5%) children completed the 2-year study. After 2 years, the mean progression of myopia and of axial elongation in the placebo-treated control eyes was -1.20+/-0.69 D and 0.38+/-0.38 mm, respectively. In the atropine-treated eyes, myopia progression was only -0.28+/-0.92 D, whereas the axial length remained essentially unchanged compared with baseline (-0.02+/-0.35 mm). The differences in myopia progression and axial elongation between the 2 groups were -0.92 D (95% confidence interval, -1.10 to -0.77 D; P<0.001) and 0.40 mm (95% confidence interval, 0.35-0.45 mm; P<0.001), respectively. No serious adverse events related to atropine were reported. CONCLUSIONS: Topical atropine was well tolerated and effective in slowing the progression of low and moderate myopia and ocular axial elongation in Asian children.

Fusion exercises for treatment of intermittent exotropia and phoria.

INTRODUCTION: Fusion exercises have been used in the management of intermittent exotropia (X(T)) for over one hundred years. The opinions regarding their efficacy are controversial. PATIENTS AND METHOD: Dynamics of binocular status were investigated retrospectively in ninety-six patients with X(T). Forty-eight subjects had specific orthoptic treatment (treatment group). Forty-eight had no orthoptic treatment (control group). Both groups were matched for age, sex, and race. The orthoptic treatment consisted of a cat stereogram, home-based fusion exercises, which patients were asked to perform twice daily. RESULTS: The treatment group showed significant enhancement of binocular function, particularly control of strabismus and stereoacuity for distance. The control group showed further deterioration of binocular functions. CONCLUSION: Our results suggest patients with X(T) objectively improve their binocular function after fusion exercises.

The ON/OFF-response in retinopathy of prematurity subjects with myopia.

Retinopathy of prematurity (ROP) is often associated with myopia. Electrophysiological findings have shown that an imbalance of the ON- and OFF-response in subjects with ROP is associated with their refractive status. Nevertheless, the extent of these functional changes is still unclear. The aim of this study was to determine the extent of the ON- and OFF-response attenuation in ROP subjects with myopia. Fast and slow m-sequence multifocal electroretinogram were recorded on 14 eyes in 8 subjects with various degrees of myopia using the VERIS system. The spherical equivalent of refractive error ranged from -0.25 to -13.50 D. All ERG recordings were made using DTL electrodes with dilated pupils. A 19 retinally scaled hexagon stimulus was used. The findings showed that the ON- and OFF-response are reduced differently in ROP subjects with myopia. The ON-response attenuation is dependant on the severity of myopia, whereas, the OFF-response attenuation is influenced by retinal eccentricity as well as the degree of myopia. The contributions of these findings toward the understanding of retinal mechanisms controlling ocular growth need to be further explored.