Birth Weight Deviation and Early Postnatal Growth Are Related to Optic Nerve Morphology at School Age in Children Born Preterm

Abstract

ABSTRACT:The aim of this study was to evaluate the influence of early and later postnatal growth variables on optic disc morphology in children (n ϭ 53) born at gestational age Ͻ32 wk. On fundus photographs taken at a median age of 5.4 y, the optic discs were evaluated using digital image analysis and compared with those of a control group (n ϭ 203). The results were analyzed in relation to gestational age, birth weight (BW) SD score (SDS), IGF-1 weight at postmenstrual age 32 wk (SDS), and weight, length, and head circumference (SDS) at follow-up. The preterm children's optic disc and neuronal rim areas were smaller than in the control group. Low BW (SDS) and weight at wk 32 (SDS) were associated with larger area of the optic cup and reduced neuronal rim area. Preterm children with known brain lesions (n ϭ 6) had significantly larger cups than preterm children without known brain lesions. The association found between both low BW and poor early growth and later reduced neuronal tissue of the optic nerve indicate that early weight gain is important for neural development in preterm children. T he prematurely born infant is prone to neuronal and vascular tissue insults when born into extrauterine life during a sensitive period of maturation of the CNS, when synaptogenesis, apoptosis, myelination, reorganization, and vasculogenesis/angiogenesis take place.Preterm birth carries a high risk for peri-or postnatal brain lesions, and brain damage is a common cause of visual impairment in children in developed countries (1). White matter damage (WMD) occurs in 30 to 50% of children born before 30-wk gestational age (GA) (2,3) or with a birth weight (BW) Ͻ1500 g (4). Periventricular leucomalacia (PVL) is frequent in children born preterm and may cause visual impairment (5) and/or cerebral palsy (6). Intraventricular hemorrhage (IVH) has been reported to occur in 61% of infants born before 34-wk GA (7). It may be associated with variable degrees of ischemia and WMD and can cause hydrocephalus that may further impair vision.Preterm birth as well as poor intrauterine 1 growth in fullterm babies has been shown to be associated with subnormal disc and neuronal rim areas of the optic nerve and with an abnormal retinal vessel pattern (8 -12). McLoone et al. (7) reported, in a group of preterm infants with IVH, a trend toward smaller optic disc, neuronal rim, and cup area with increasing severity of IVH, but only children with IVH grade IV were reported to have a significantly increased incidence of optic nerve hypoplasia. They found no association between the optic disc morphology and timing of brain injury. Large cups in normal-sized optic discs have been reported in preterm children with PVL born at GA Ͻ37 wk (12). In another study, children with PVL had a significantly smaller disc area if the damage was estimated to have occurred before 28 postmenstrual weeks and a larger cup of the optic disc and a smaller neuronal rim area if the cerebral WMD was estimated to have occurred later than 28 postmenstrual weeks (13). Children ...

Optic disc morphology in premature infants

“…In contrast with the previously mentioned studies of de Silva,13 McLoone17 and the present study, Hellström,3 4 Wikstrand18 and Jacobson6 took digitised fundus photographs to analyse the optic disc of the children.…”

“…This correlates with the findings in our study, in which 73% of the examined prematures had disc cupping. Wikstrand et al 18 examined 53 children born at a gestational age <32 weeks at a mean age of 5.4 years. They found that low birth weight and poor weight gain during the first weeks of life were associated with a larger area of the optic cup as well as with a smaller neuronal rim area of the optic nerve head.…”

Retinal nerve fibre layer thickness in school-aged prematurely-born children compared to children born at term

“…Loss of axons is compensated for by increase in glia cells. Wikstrand et al showed that the optic disc neural rim area was smaller in children born preterm and that there were correlations with low birth weight as well as poor postnatal growth 21. They suggested that poor early growth could affect the neural development in this group of children.…”

Cup-to-disc and arteriole-to-venule ratios in preterm birth

“…3 During follow-up of children previously screened for ROP, we received the impression that they often had a large cup-todisc (C/D) ratio and a small arteriole-to-venule (A/V) ratio. In 2010, Wikstrand et al 4 reported the association of low birth weight and weight at gestational age (GA) of 32 weeks with large area of the optic disc cup in preterm birth. Plus disease, an indicator of ROP severity, may present a constellation of signs including retinal arterial tortuosity and venous dilation at the posterior pole, vitreous haze, and iris rigidity.…”