RetCam image analysis of optic disc morphology in premature infants and its relation to ischaemic brain injury

Abstract

Aims: To assess optic disc characteristics in premature infants with and without ischaemic brain injury and to evaluate the role of optic disc morphology in dating the injury. Methods: RetCam fundal images, cranial ultrasounds and magnetic resonance imaging (MRI) of 109 premature infants were analysed. The study cohort was divided into subgroups depending on the presence or absence of periventricular leucomalacia (PVL) and intraventricular haemorrhage (IVH). The control group consisted of infants with normal neuroimaging at term and 2 years of age. Using the image analysis software of the RetCam, optic disc diameter (ODD), optic disc area (ODA), and optic cup area (OCA) were measured at 33-34 weeks gestational age. As serial cranial ultrasonography had been performed, it was possible to date the brain injury in those infants with periventricular white matter (PVWM) damage. Results: Although there was a trend towards reducing ODD, ODA, and OCA with increasing severity of IVH, only the IVH 4 group differed significantly from the controls for these parameters (p = 0.002, p = 0.02, and p = 0.04, respectively). 44.4% of infants with grade 4 IVH had small discs. Only one patient had a large cup in a normal sized disc; this patient had IVH 4. In patients with PVWM damage, the median time of insult was 27 weeks in those with small discs and 28 weeks in those with normal discs. This difference was not significant (p = 0.23). Conclusions: Premature infants with IVH 4 have an increased incidence of optic nerve hypoplasia. We found no association between disc morphology and timing of brain injury.

Retinal nerve fiber layer thickness in prematurity is correlated with stage of retinopathy of prematurity

“…Periventricular hemorrhage, which is more frequently found in very low birth weight infants has been reported to be associated with reduced optic disc diameter, optic disc area, and optic cup area. 18 We could not include the presence of periventricular hemorrhage in the multivariable analysis because there were only two patients who had periventricular hemorrhage. We hope further studies will clearly reveal the association between peripapillary RNFL distribution and the presence of severe intraventricular hemorrhage.…”

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

“…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.…”

“…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.…”

RetCam image analysis of the optic disc in premature infants

“…8 Conversion of the figure measurement from pixels to mm was carried out according to the formula presented in a previous study, and 0.0176 mm/pixel was applied to the 80-degree lens used in this study; twisting or distortion of pictures which can be caused by a camera were ignored. 8,11 Gestational age and birth weight were investigated retrospectively using medical records. We evaluated the relationship of the optic CD ratio, CD area ratio, the disc area, and rim area with gestational age or birth weight.…”

“…7 Other studies reported that the CD ratio significantly increased in premature babies with ischemic brain lesions compared with normal babies. [8][9][10] These studies show that the optic disc shape can change because of several factors at birth. However, there are limitations in the previous studies investigating the relationship of optic disc shape and premature infants, because most of these have examined the optic disc shape in children approximately 10 years of age.…”