Abstract
Purpose :
Children born very preterm (< 32 weeks' gestational age) are at risk of neonatal hyperglycaemia, impaired vision and abnormal ocular development. We investigated the relationship between neonatal hyperglycaemia, visual acuity (VA) and ocular biometry in seven-year old children born very preterm.
Methods :
Children born at < 30 weeks’ gestational age (GA) or < 1500g birth weight (BW) with neonatal hyperglycaemia (two consecutive blood glucose concentrations (BGC) > 8.5 mmol.L-1 at least 4 hours apart) (cases) were matched with controls without neonatal hyperglycaemia by sex, GA, BW, date of birth, socio-economic status and multiple birth. Visual acuity (VA) was measured using a Keeler Crowded logMAR chart. Ocular biometry including corneal thickness, anterior chamber depth, axial length, lens thickness and corneal curvature was measured using a Lenstar LS900 Non-contact Biometer (Haag-Streit Diagnostics, Japan). Data are summarised in median (IQR) or mean ± SD. Outcomes were compared between groups using linear regression. Results are presented as unstandardised coefficient (β) and 95% confidence interval (CI).
Results :
111 children were assessed at 7.2 ± 0.1 years of age (57 cases, 54 controls: GA 25 (25 - 27) vs 26 (26 - 28) weeks; BW: 790 (700 - 863) vs 988 (879 - 1130) g). VA in the better eye did not differ between groups (0.00 ± 0.16 v -0.04 ± 0.12 logMAR, p = 0.18) but binocular VA was poorer in cases (0.00 ± 0.16 vs -0.09 ± 0.11 logMAR, p = 0.03). In the eye with better VA, cases had a thicker lens (3.83 ± 0.27 v 3.69 ± 0.22 mm, p = 0.03). Other biometry measurements did not differ between the groups. Mean lens thickness increased by 0.10 mm (95% CI 0.05 - 0.15, p < 0.0001) per 1 mmol.L-1 increase in mean BGC in the first month after birth. Mean visual acuity increased by 0.25 logMAR (95% CI 0.16 - 0.34, p < 0.0001) per 1 mm increase in lens thickness.
Conclusions :
Neonatal hyperglycaemia was associated with increased lens thickness at 7 years of age. This increased lens thickness is similar to that found in long-standing adult type I and II diabetes mellitus, suggesting that transient increases in BGC may have long-term effects on ocular growth and visual acuity.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.