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

Aim To investigate the retinal nerve fibre layer (RNFL) with optical coherent tomography (OCT) in prematurely-born children.

Methods 62 children born with a gestational age of ≤32 weeks, and a control group of 54 children born at term with normal birth weight (BW) were included in the study. 28 of the preterm children had retinopathy of prematurity (ROP) in the neonatal period; eight of them had severe ROP (stages 3–4). RNFL thickness was measured with Stratus OCT 3. Mean age at examination was 8.6 years in the preterm children and 10.1 years in the control group.

Results There was a significant difference between the children born preterm and those born at term, regarding RNFL thickness in the superior (right eye (RE), p=0.043; left eye (LE), p=0.048) and the nasal quadrants (RE, p=0.006; LE, p<0.001), as well as average RNFL thickness (RE, p=0.016; LE, p=0.029). This difference was caused by the thinner RNFL in children with previous severe ROP (stages 3 and 4). Within the preterm group, the average RNFL thickness increased with larger BW (RE, p=0.050; LE, p=0.028), but there was no correlation with gestational age at birth.

Conclusion The RNFL was reduced in prematurely-born children with severe ROP when compared to children born at term. It is hypothesised that severe retinopathy as well as ablation of the retina with laser treatment or cryotherapy may affect the axons of the ganglion cells and thus reduce RNFL thickness. Prematurely-born children with low BW had a thinner RNFL, suggesting a negative effect of low birth weight on neural development.