Related Experiment Video
Updated: Apr 9, 2026
Author Spotlight: Ex Vivo OCT-Based Multimodal Imaging of Human Donor Eyes for Research into Age-Related Macular Degeneration
Published on: May 26, 2023
A methodological approach for evaluation of foveal immaturity after extremely preterm birth
Rebecka Rosén1, Johan Sjöstrand2, Maria Nilsson1
1Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
Insights
Extremely preterm birth before 27 weeks gestational age (GA) leads to lasting foveal anatomical changes in children, including reduced foveal depth. Gestational age is the key factor influencing foveal development, even in those with retinopathy of prematurity.
Area of Science:
- Ophthalmology
- Developmental Biology
- Neonatology
Background:
- Premature birth can impact retinal development.
- Understanding long-term foveal microanatomy in extremely preterm infants is crucial.
Purpose of the Study:
- To characterize persistent foveal microanatomical alterations in children born extremely preterm (before 27 weeks gestational age).
- To evaluate a clinical methodological tool for assessing these changes.
Main Methods:
- Optical Coherence Tomography (OCT) scans of the fovea were analyzed in 40 children at 6.5 years of age.
- Subjects were grouped by gestational age (GA) and presence of retinopathy of prematurity (ROP).
- A grading system was applied to OCT scans to assess foveal microanatomy.
Main Results:
- Children born preterm showed significantly reduced foveal depth and thicker inner retinal and outer nuclear layers compared to full-term controls.
- Foveal depth and inner retinal layer thickness correlated with GA.
- Foveal depth increased with gestational age between 23 and 27 weeks.
Conclusions:
- Premature birth before 27 weeks GA commonly results in persistent foveal anatomical alterations, notably reduced foveal depth and incomplete inner retinal layer extrusion.
- The outer fovea appears to develop well, irrespective of prematurity.
- Gestational age is the primary determinant of foveal maturation in preterm infants.
Purpose:
To characterize typical microanatomical alterations of immaturity in the fovea, that remain into childhood, after extremely preterm birth before 27 weeks gestational age (GA) and to suggest a clinical methodological evaluation tool.
Methods:
Subjects were consecutively recruited at age 6.5 years and organized in four groups (10 subjects in each): Group A (full-term), Group B (GA 25-27 weeks) without retinopathy of prematurity (ROP), Group B* (GA 25-27 weeks) and Group C (GA 23-24 weeks) both with ROP stage 3. Foveal microanatomy was studied using a grading system of OCT-scans.
Results:
Prematurely born children (including Group B, B* and C) had significantly reduced foveal depth (mean difference -53 μm, p < 0.001), thicker inner retinal layer (mean difference 21.6, p = 0.005) and thicker outer nuclear layer (mean difference 23.5, p < 0.001) than controls. Foveal depth and inner retinal layer thickness were significantly correlated to GA (p = 0.003 and p = 0.017 respectively) within the preterm group. Foveal depth increased with 14.1 μm per week between GA 23 and 27. The three hyper reflective bands of the outer segments as well as a central protuberance of inner and outer segment layers were present in all children.
Conclusion:
Previous studies have revealed signs of immaturity affecting most retinal layers at time of birth in prematurely born children. The present study adds information to which extent these signs of underdevelopment remains to later in life. The applied method showed that premature birth before GA 27 weeks commonly leads to characteristic anatomical alterations of the foveal anatomy expressed as reduced foveal depth and incomplete extrusion of the inner retinal layers. Although deviations of the outer nuclear layers can be seen in the most extremely preterm born children, the outer part of the fovea generally develops well, independent of prematurity. The single most important determinant for the degree of foveal maturation seems to be GA.
