Comparison of refractive error and central corneal thickness in neonates of diabetic and healthy mothers

Association between hyperglycemia during pregnancy and offspring's refractive error: A focused review

This review article explores the relationship between hyperglycemia during pregnancy and the visual development of offspring, specifically focusing on refractive error. The authors conducted a comprehensive search for relevant articles in various databases and assessed the methodological quality of the included studies. The findings consistently indicate that hyperglycemia during pregnancy can have a detrimental impact on the structural and functional aspects of visual development in offspring. The intrauterine hyperglycemic environment appears to negatively affect the retina and lens, leading to refractive errors. In conclusion, there is likely an association between hyperglycemia during pregnancy and the development of refractive errors in offspring.

Refractive development I: Biometric changes during emmetropisation

PURPOSE

Although there are many reports on ocular growth, these data are often fragmented into separate parameters or for limited age ranges. This work intends to create an overview of normal eye growth (i.e., in absence of myopisation) for the period before birth until 18 years of age.

METHODS

The data for this analysis were taken from a search of six literature databases using keywords such as "[Parameter] & [age group]", with [Parameter] the ocular parameter under study and [age group] an indication of age. This yielded 34,409 references that, after screening of title, abstract and text, left 294 references with usable data. Where possible, additional parameters were calculated, such as the Bennett crystalline lens power, whole eye power and axial power.

RESULTS

There were 3422 average values for 17 parameters, calculated over a combined total of 679,398 individually measured or calculated values. The age-related change in refractive error was best fitted by a sum of four exponentials (r²  = 0.58), while all other biometric parameters could be fitted well by a sum of two exponentials and a linear term ('bi-exponential function'; r² range: 0.64-0.99). The first exponential of the bi-exponential fits typically reached 95% of its end value before 18 months, suggesting that these reached genetically pre-programmed passive growth. The second exponentials reached this point between 4 years of age for the anterior curvature and well past adulthood for most lenticular dimensions, suggesting that this part represents the active control underlying emmetropisation. The ocular components each have different growth rates, but growth rate changes occur simultaneously at first and then act independently after birth.

CONCLUSIONS

Most biometric parameters grow according to a bi-exponential pattern associated with passive and actively modulated eye growth. This may form an interesting reference to understand myopisation.

Association of maternal diabetes during pregnancy with visual acuity development in offspring: a prospective cohort study

AIMS

We aimed to investigate the association between maternal diabetes before or during pregnancy and visual acuity development in offspring at 1 and 4 years old.

METHODS

This prospective cohort study comprised 301 individuals born in 2015-2017. Those who had maternal diabetes during or before pregnancy (type 1 diabetes, type 2 diabetes and gestational diabetes) were investigated. Two visual examinations were routinely performed on children relatively at the age of 1 at physical examination and at the age of 4 at admission to school to assess the possible effects of gestational exposure to diabetes on the visual system of the offspring.

RESULTS

Data were collected on children aged 1 and 4, which consisted of 173 children of mothers exposed to diabetes and 128 children of mothers without diabetes). We found no significant association between maternal diabetes during pregnancy and visual acuity development in 1-year-old offspring. At 4 years old, the incidence of amblyopia and strabismus was similar in both groups. Prenatal exposure to maternal diabetes was associated with a 171% increased risk of high RE: OR 2.71 (95% CI 1.08, 6.81), p < 0.05. Astigmatism (13.3% vs 5.5%) was found to be significantly more prevalent in children born to mothers with GD than in the controls (p = 0.025 in both groups). Moreover, offspring exposed to PGDM had a higher overall risk of high RE than those exposed to GDM during pregnancy (25.0% vs 17.4%). We further found that in the offspring of diabetic mothers, the risk of high RE was significantly increased among children who were female or who spent more time using electronic devices daily.

CONCLUSIONS

Our findings suggest that maternal diabetes during pregnancy is associated with an increased risk of high RE in offspring. Regular ophthalmological screening should be advised to offspring of mothers with diabetes diagnosed before or during pregnancy.

Normal range of ocular biometry in healthy children: A systemic review and meta-analysis of 33,559 individuals under seven years of age

PURPOSE

To conduct a systemic review and meta-analysis on the normative range of ocular biometry in healthy children under seven years of age.

METHODS

A literature search was performed using the PubMed (MEDLINE) database. The main outcomes were normative values of axial length (AL), central corneal thickness (CCT), cornea curvature (CC), anterior chamber depth (ACD), lens thickness (LT) and vitreous chamber depth (VCD). Pooled estimates were obtained with a random-effects meta-analysis. Multivariate meta-regressions ascertained the moderator-related trends.

RESULTS

We included 47 studies for a total of 33,559 subjects. The pooled ALs for 0.0-1.9 years, 2.0-3.9 years and 4.0-6.9 years were 18.33 mm (95% confidence interval [CI] 17.57-19.09), 21.71 mm (21.49-21.93) and 22.37 mm (22.29-22.45), respectively. Children aged 0.0-1.9 years had a greater CCT (576.70 μm, 567.20-586.21), steeper cornea (7.41 mm, 7.16-7.65) and shallower ACD (2.46 mm, 2.23-2.69). LT ranged from 3.65 to 3.74 mm for 0-6 years, and VCD increased from 11.94 mm at birth to 15.36 mm at 4.0-6.9 years. Differences in AL between East Asian and non-East Asian children were found below two years of age (17.30 mm vs. 18.40 mm, p = 0.008) and for CC at 4.0-6.9 years of age (7.82 mm vs. 7.79 mm, p = 0.004). In a multivariate meta-regression, AL, CC, ACD and VCD increased with age (p < 0.05 for all), while CCT decreased with age (p = 0.0007).

CONCLUSIONS

This study reports normative data for ocular biometry in children. Few differences were found with ethnicity in the ocular biometry of infants and pre-schoolers.

Association of maternal diabetes during pregnancy with high refractive error in offspring: a nationwide population-based cohort study

AIMS/HYPOTHESIS

We aimed to investigate the associations between maternal diabetes before or during pregnancy and the risk of high refractive error (RE) in offspring until the age of 25 years.

METHODS

This nationwide register-based cohort study comprised 2,470,580 individuals born in 1977-2016. The exposure was maternal diabetes during or before pregnancy (type 1 diabetes, type 2 diabetes and gestational diabetes). Cox regression was used to examine the association between maternal diabetes and the risk of high RE in offspring from birth until the age of 25 years, adjusting for multiple potential confounders.

RESULTS

During up to 25 years of follow-up, 553 offspring of mothers with diabetes and 19,695 offspring of mothers without diabetes were diagnosed with high RE. Prenatal exposure to maternal diabetes was associated with a 39% increased risk of high RE: HR 1.39 (95% CI 1.28, 1.51), p < 0.001; standardised cumulative incidence in unexposed offspring at 25 years of age 1.18% (95% CI 1.16%, 1.19%); cumulative incidence difference 0.72% (95% CI 0.51%, 0.94%). The elevated risks were observed for hypermetropia (HR 1.37 [95% CI 1.24, 1.51], p < 0.001), myopia (HR 1.34 [95% CI 1.08, 1.66], p = 0.007) and astigmatism (HR 1.58 [95% CI 1.29, 1.92], p < 0.001). The increased risks were more pronounced among offspring of mothers with diabetic complications (HR 2.05 [95% CI 1.60, 2.64], p < 0.001), compared with those of mothers with diabetes but no diabetic complications (HR 1.18 [95% CI 1.02, 1.37], p = 0.030).

CONCLUSIONS/INTERPRETATION

Our findings suggest that maternal diabetes during pregnancy is associated with an increased risk of high RE in offspring, in particular among those of mothers with diabetic complications. Early ophthalmological screening should be recommended in offspring of mothers with diabetes diagnosed before or during pregnancy.