Abstract
Purpose :
Previously, we compared the macular structure and visual function in children born premature and full-term diagnosed with foveal hypoplasia.(Jin et al 2022) The fovea was thicker in both hypoplasia groups than in full-term normal children. In contrast, the full-term hypoplasia (FH) group is associated with more severe structure changes and poorer visual function than the preterm hypoplasia (PH) group. Thus, we hypothesize that eccentric fixation in the FH is higher than in the PH group. This study tested this hypothesis by comparing the OCT eccentric fixation of these two groups.
Methods :
Three groups of children (3-18 years old) were compared: 1) full-term hypoplasia (FH, n=59, gestational age ≥36 weeks); the FH groups included albinism, Down syndrome, and other neurological or systematic diseases.. 2) preterm hypoplasia (PH, N=57, gestational age <=31 weeks, birth weight <=1500 g); 3) control (n=54), full-term normal. Foveal hypoplasia was graded according to the Leicester Grading System. Spectral-domain OCT macular scan images were used to estimate eccentric fixation. We asked the child to focus on the internal blue dot fixation target of the OCT. OCT eccentric fixation (OCT-EF), i.e., the distance between the foveal center and the fixation point, was measured, adjusted for axial length, and converted into visual degrees. OCT-EF in the right eye of the three groups was compared by the Kruskal-Wallis test and further compared with the pairwise Wilcox test.
Results :
The OCT-EF in degree was 0.21±0.31 for the control, 1.02±1.44 for the FH, and 0.84±1.77 for the PH groups (Chi-squared=8.46, p=0.01), where the FH group had higher OCT-EF than the control group (pairwise comparison, p=0.01). LogMAR visual acuity was worse in the full-term hypoplasia group (0.35±0.36) than in the premature hypoplasia group (0.19±0.27, p<0.001). LogMAR visual acuity was correlated with OCT-EF (r=0.55, p <0.001).
Conclusions :
Compared with the normal control group, children from both hypoplasia groups often had significant OCT-EF, which was correlated with their degraded visual function.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.