Abstract
Purpose: :
To investigate the retinal nerve fibre layer (RNFL) and optic nerve head with optical coherent tomography (OCT) and Heidelberg retinal tomography (HRT) in prematurely-born children and children born at term.
Methods: :
Sixty-one children born before gestational age of 33 weeks together with a control group of fifty-five children born at term and with normal birth weight, were included in the study. Twenty-nine of the preterm children had ROP in the neonatal period and five were treated. RNFL was measured with Stratus OCT 3 and HRT III. The optic nerve head parameters, including disc area (RA) and rim area (RA), were assessed with HRT. The mean age at examination was 8.5 years in the preterm children and 10.1 years in the control group.
Results: :
The mean visual acuity was 1.0 in right (RE) and left eyes (LE) in the preterm group compared to 1.2 in the full-term group (p<0.001). The RNFL assessed with OCT was 97 (SD13) µm in RE’s and 95 (SD 11) µm in LE’s in the prematurely-born children compared to 98 (SD 7.8) µm in the full-term ones. The prematurely-born children had a tendency for smaller DA, 2.04 (SD 0.42) mm2 RE and 2.06 (SD 0.43) mm2 LE compared to 2.16 (SD 0.47) mm2 in the children born at term. The RA was significantly smaller in both eyes, 1.56 (SD 0.28) mm2 RE and 1.58 (SD 0.30) mm2 LE in the preterm group compared to 1.75 (SD 0.39) mm2 in the full-term group (p=0.004 RE and p=0.01LE). In the preterm group, there were no correlations regarding RNFL, DA or RA, to gestational age at birth, birth weight, stage of ROP or neurology.
Conclusions: :
Prematurely-born children had lower visual acuity, but we could not prove that the reason for this was a reduced RNFL. However, with HRT, there was a trend for smaller DA and a significantly reduced RA. We have previously found thicker foveae in prematurely-born children. Thus, the reason for reduced visual acuity may be both retinal and/or neuronal and remains to be elucidated.
Keywords: imaging/image analysis: clinical • nerve fiber layer • optic disc