Dextrose gel prophylaxis for neonatal hypoglycaemia and neurocognitive function at early school age: a randomised dosage trial

OBJECTIVE

To investigate the effect of different doses of prophylactic dextrose gel on neurocognitive function and health at 6-7 years.

DESIGN

Early school-age follow-up of the pre-hPOD (hypoglycaemia Prevention with Oral Dextrose) study.

SETTING

Schools and communities.

PATIENTS

Children born at ≥35 weeks with ≥1 risk factor for neonatal hypoglycaemia: maternal diabetes, small or large for gestational age, or late preterm.

INTERVENTIONS

Four interventions commencing at 1 hour of age: dextrose gel (40%) 200 mg/kg; 400 mg/kg; 200 mg/kg and 200 mg/kg repeated before three feeds (800 mg/kg); 400 mg/kg and 200 mg/kg before three feeds (1000 mg/kg); compared with equivolume placebo (combined for analysis).

MAIN OUTCOMES MEASURES

Toolbox cognitive and motor batteries, as well as tests of motion perception, numeracy and cardiometabolic health, were used. The primary outcome was neurocognitive impairment, defined as a standard score of more than 1 SD below the age-corrected mean on one or more Toolbox tests.

FINDINGS

Of 392 eligible children, 309 were assessed for the primary outcome. There were no significant differences in the rate of neurocognitive impairment between those randomised to placebo (56%) and dextrose gel (200 mg/kg 46%: adjusted risk difference (aRD)=-14%, 95% CI -35%, 7%; 400 mg/kg 48%: aRD=-7%, 95% CI -27%, 12%; 800 mg/kg 45%: aRD=-14%, 95% CI -36%, 9%; 1000 mg/kg 50%: aRD=-8%, 95% CI -29%, 13%). Children exposed to any dose of dextrose gel (combined), compared with placebo, had a lower risk of motor impairment (3% vs 14%, aRD=-11%, 95% CI -19%, -3%) and higher mean (SD) cognitive scores (106.0 (15.3) vs 101.1 (15.7), adjusted mean difference=5.4, 95% CI 1.8, 8.9).

CONCLUSIONS

Prophylactic neonatal dextrose gel did not alter neurocognitive impairment at early school age but may have motor and cognitive benefits. Further school-age follow-up studies are needed.

Neonatal Hypoglycemia and Neurocognitive Function at School Age: A Prospective Cohort Study

OBJECTIVE

To determine the relationship between transient neonatal hypoglycemia in at-risk infants and neurocognitive function at 6-7 years of corrected age.

STUDY DESIGN

The pre-hPOD Study involved children born with at least 1 risk factor for neonatal hypoglycemia. Hypoglycemia was defined as ≥1 consecutive blood glucose concentrations <47 mg/dl (2.6 mmol/L), severe as <36 mg/dl (2.0 mmol/L), mild as 36 to <47 mg/dL (2.0 to <2.6 mmol/L), brief as 1-2 episodes, and recurrent as ≥3 episodes. At 6-7 years children were assessed for cognitive and motor function (NIH-Toolbox), learning, visual perception and behavior. The primary outcome was neurocognitive impairment, defined as >1 SD below the normative mean in ≥1 Toolbox tests. The 8 secondary outcomes covered children's cognitive, motor, language, emotional-behavioral, and visual perceptual development. Primary and secondary outcomes were compared between children who did and did not experience neonatal hypoglycemia, adjusting for potential confounding by gestation, birthweight, sex and receipt of prophylactic dextrose gel (pre-hPOD intervention). Secondary analysis included assessment by severity and frequency of hypoglycemia.

RESULTS

Of 392 eligible children, 315 (80%) were assessed at school age (primary outcome, n = 308); 47% experienced hypoglycemia. Neurocognitive impairment was similar between exposure groups (hypoglycemia 51% vs 50% no hypoglycemia; aRD -4%, 95% CI -15%, 7%). Children with severe or recurrent hypoglycemia had worse visual motion perception and increased risk of emotional-behavioral difficulty.

CONCLUSION

Exposure to neonatal hypoglycemia was not associated with risk of neurocognitive impairment at school-age in at-risk infants, but severe and recurrent episodes may have adverse impacts.

TRIAL REGISTRATION

Hypoglycemia Prevention in Newborns with Oral Dextrose: the Dosage Trial (pre-hPOD Study): ACTRN12613000322730.

Non-invasive brain stimulation and vision rehabilitation: a clinical perspective

Non-invasive brain stimulation techniques allow targeted modulation of brain regions and have emerged as a promising tool for vision rehabilitation. This review presents an overview of studies that have examined the use of non-invasive brain stimulation techniques for improving vision and visual functions. A description of the proposed neural mechanisms that underpin non-invasive brain stimulation effects is also provided. The clinical implications of non-invasive brain stimulation in vision rehabilitation are examined, including their safety, effectiveness, and potential applications in specific conditions such as amblyopia, post-stroke hemianopia, and central vision loss associated with age-related macular degeneration. Additionally, the future directions of research in this field are considered, including the need for larger and more rigorous clinical trials to validate the efficacy of these techniques. Overall, this review highlights the potential for brain stimulation techniques as a promising avenue for improving visual function in individuals with impaired vision and underscores the importance of continued research in this field.

Novel Quantitative Contrast Sensitivity Function Enhances the Prediction of Treatment Outcome and Recurrence in Amblyopia

Purpose

Although effective amblyopia treatments are available, treatment outcome is unpredictable, and the condition recurs in up to 25% of the patients. We aimed to evaluate whether a large-scale quantitative contrast sensitivity function (CSF) data source, coupled with machine learning (ML) algorithms, can predict amblyopia treatment response and recurrence in individuals.

Methods

Visual function measures from traditional chart vision acuity (VA) and novel CSF assessments were used as the main predictive variables in the models. Information from 58 potential predictors was extracted to predict treatment response and recurrence. Six ML methods were applied to construct models. The SHapley Additive exPlanations was used to explain the predictions.

Results

A total of 2559 consecutive records of 643 patients with amblyopia were eligible for modeling. Combining variables from VA and CSF assessments gave the highest accuracy for treatment response prediction, with the area under the receiver operating characteristic curve (AUC) of 0.863 and 0.815 for outcome predictions after 3 and 6 months, respectively. Variables from the VA assessment alone predicted the treatment response, with AUC values of 0.723 and 0.675 after 3 and 6 months, respectively. Variables from the CSF assessment gave rise to an AUC of 0.909 for recurrence prediction compared to 0.539 for VA assessment alone, and adding VA variables did not improve predictive performance. The interocular differences in CSF features are significant contributors to recurrence risk.

Conclusions

Our models showed CSF data could enhance treatment response prediction and accurately predict amblyopia recurrence, which has the potential to guide amblyopia management by enabling patient-tailored decision making.

Prenatal Magnesium Sulfate and Functional Connectivity in Offspring at Term-Equivalent Age

Importance

Understanding the effect of antenatal magnesium sulfate (MgSO4) treatment on functional connectivity will help elucidate the mechanism by which it reduces the risk of cerebral palsy and death.

Objective

To determine whether MgSO4 administered to women at risk of imminent preterm birth at a gestational age between 30 and 34 weeks is associated with increased functional connectivity and measures of functional segregation and integration in infants at term-equivalent age, possibly reflecting a protective mechanism of MgSO4.

Design, Setting, and Participants

This cohort study was nested within a randomized placebo-controlled trial performed across 24 tertiary maternity hospitals. Participants included infants born to women at risk of imminent preterm birth at a gestational age between 30 and 34 weeks who participated in the MAGENTA (Magnesium Sulphate at 30 to 34 Weeks' Gestational Age) trial and underwent magnetic resonance imaging (MRI) at term-equivalent age. Ineligibility criteria included illness precluding MRI, congenital or genetic disorders likely to affect brain structure, and living more than 1 hour from the MRI center. One hundred and fourteen of 159 eligible infants were excluded due to incomplete or motion-corrupted MRI. Recruitment occurred between October 22, 2014, and October 25, 2017. Participants were followed up to 2 years of age. Analysis was performed from February 1, 2021, to February 27, 2024. Observers were blind to patient groupings during data collection and processing.

Exposures

Women received 4 g of MgSO4 or isotonic sodium chloride solution given intravenously over 30 minutes.

Main Outcomes and Measures

Prior to data collection, it was hypothesized that infants who were exposed to MgSO4 would show enhanced functional connectivity compared with infants who were not exposed.

Results

A total of 45 infants were included in the analysis: 24 receiving MgSO4 treatment and 21 receiving placebo; 23 (51.1%) were female and 22 (48.9%) were male; and the median gestational age at scan was 40.0 (IQR, 39.1-41.1) weeks. Treatment with MgSO4 was associated with greater voxelwise functional connectivity in the temporal and occipital lobes and deep gray matter structures and with significantly greater clustering coefficients (Hedge g, 0.47 [95% CI, -0.13 to 1.07]), transitivity (Hedge g, 0.51 [95% CI, -0.10 to 1.11]), local efficiency (Hedge g, 0.40 [95% CI, -0.20 to 0.99]), and global efficiency (Hedge g, 0.31 [95% CI, -0.29 to 0.90]), representing enhanced functional segregation and integration.

Conclusions and Relevance

In this cohort study, infants exposed to MgSO4 had greater voxelwise functional connectivity and functional segregation, consistent with increased brain maturation. Enhanced functional connectivity is a possible mechanism by which MgSO4 protects against cerebral palsy and death.

Associations between the cause of amblyopia and pre-treatment contrast sensitivity, stereoacuity, fixation, and nystagmus

Purpose

To explore the association between the cause of amblyopia and pre-treatment contrast sensitivity, stereoacuity, fixation and nystagmus.

Design

Retrospective cohort study.

Methods

A retrospective review was conducted for 3408 patients with amblyopia who had not yet started amblyopia treatment utilizing a large amblyopia patient database maintained at Zhongshan Ophthalmic Centre. Six amblyogenic factor subtypes were identified: anisometropia, isoametropia, strabismus, anisometropia and strabismus, monocular visual deprivation, and binocular visual deprivation amblyopia. Monocular best corrected visual acuity (BCVA), the contrast sensitivity function (CSF), fixation, and stereopsis were compared between the subtypes before and after propensity score matching (PSM) for age and sex.

Results

The two deprivation groups had poorer BCVA and CSF than the other groups. There were no systematic differences in CSF between the non-deprivation groups. Nystagmus was more common in the bilateral amblyopia groups compared to the monocular amblyopia groups. Eccentric fixation was uncommon with the exception of the anisometropia and strabismus group which had an eccentric fixation rate of 20%. Distance stereoacuity measured without monocular cues was absent for almost all patients. The results were consistent when analyzed using PSM.

Conclusion

Visual deprivation causes more severe amblyopia than other amblyogenic factors. For non-deprivation amblyopia subtypes, individual differences such as variation in the severity of the amblyogenic factor might be more important in determining pre-treatment vision than whether amblyopia was caused by refractive error, strabismus or both.

Associations between neonatal nutrition and visual outcomes in 7-year-old children born very preterm

PURPOSE

There is uncertainty about the effect of increased neonatal protein intake on neurodevelopmental outcomes following preterm birth. The aim of this study was to assess the effect of a change in neonatal nutrition protocol at a major tertiary neonatal intensive care unit intended to increase protein intake on ophthalmic and visual development in school-age children born very preterm.

METHODS

The study cohort comprised children (n = 128) with birthweight <1500 g or gestational age < 30 weeks born at Auckland City Hospital before (OldPro group, n = 55) and after (NewPro group, n = 73) a reformulation of parenteral nutrition that resulted in increased total protein intake during the first postnatal week and decreased carbohydrate, total parenteral fluid and sodium intake. Clinical and psychophysical vision assessments were completed at 7 years' corrected age, including visual acuity, global motion perception (a measure of dorsal stream function), stereoacuity, ocular motility and ocular health. Composite measures of favourable overall visual, binocular and functional visual outcomes along with individual vision measures were compared between the groups using logistic and linear regression models.

RESULTS

Favourable overall visual outcome did not differ between the two groups. However, global motion perception was better in the NewPro group (p = 0.04), whereas the OldPro group were more likely to have favourable binocular visual outcomes (60% vs. 36%, p = 0.02) and passing stereoacuity (p = 0.02).

CONCLUSIONS

These results indicate subtle but complex associations between early neonatal nutrition after very preterm birth and visual development at school age.