Foveal thickness and its association with visual acuity in adults born preterm with very low birth weight: A two-country birth cohort study.

Abstract

To explore foveal and parafoveal thickness in adults born preterm with very low birth weight (VLBW) and its association with best-corrected visual acuity (BCVA) and gestational age (GA) compared to adults born at term. In a joint study of the Helsinki Study of Very Low Birth Weight Adults (Finland) and the NTNU Low Birth Weight Life study (Norway), 106 VLBW and 143 term-born controls were examined with spectral-domain optical coherence tomography and BCVA at age 31-43 years. Thickness of retinal layers was segmented in the foveal and parafoveal areas of the macula. The total retinal thickness in the foveal area was thicker in VLBW adults compared with controls; mean (SD): 292.5 μm (28.2) and 272.4 μm (20.2); p < 0.001, and thinner in the parafoveal areas of the macula. These findings could be explained by a thicker inner retinal layer in the foveal area found in VLBW adults compared with controls (mean difference 20.4 μm; CI: 15.0 to 25.9), where a thicker fovea was associated with lower GA, but not BCVA. Adults born preterm with VLBW had a thicker retina in the foveal area than controls and this was associated with GA, but not with BCVA. These changes seem to be related to a thicker inner retinal layer in VLBW adults. The findings imply that signs of macular underdevelopment are still present in adulthood, but not necessarily related to reduced visual function.