Foveal avascular zone and foveal pit formation after preterm birth
- Susan E Yanni1,
- Jingyun Wang2,
- Melody Chan3,
- Joseph Carroll4,
- Sina Farsiu3,5,
- Joel N Leffler6,
- Rand Spencer7,
- Eileen E Birch1,6
- 1Retina Foundation of the Southwest, Dallas, Texas, USA
- 2Eugene and Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, Indiana, USA
- 3Biomedical Engineering, Duke University, Durham, North Carolina, USA
- 4Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
- 5Department of Ophthalmology, Duke University, Durham, North Carolina, USA
- 6Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, USA
- 7Texas Retina Associates, Dallas, Texas, USA
- Correspondence to Dr Susan Elizabeth Yanni, Retina Foundation of the Southwest, 9900 North Central Expressway, Suite 400, Dallas, TX 75231-0920, USA;
Contributors SY collected data, analysed data, performed statistical analyses, wrote the manuscript and edited the manuscript. JW collected data, analysed data, evaluated methodological reproducibility and edited the manuscript. MC performed data analysis and edited the manuscript. JC provided data analysis programs and edited the manuscript. SF provided data analysis tools and programs, analysed data and edited the manuscript. JL referred patients to the study and edited the manuscript. RS referred patients to the study and edited the manuscript. EB designed the study, provided infrastructure for data collection, assisted with statistical analyses and edited the manuscript. All authors were involved in revising the manuscript prior to final approval and submission.
- Accepted 6 April 2012
- Published Online First 29 April 2012
Background Vascularisation of the macula takes place between 24 and 27 weeks post-conception. Preterm birth may affect the formation of the foveal avascular zone (FAZ) and foveal depression, and displacement of inner retinal layers away from the incipient fovea.
Objective To examine whether vascular abnormalities accompany an inner retinal abnormality, and whether they are coincident.
Methods High-density spectral domain optical coherence tomography volume scans were obtained from 24 preterm children and 34 full-term controls (5–16 years). Matlab programs were used to quantify total retinal thickness, thickness of individual retinal layers and metrics of foveal morphology. Summed voxel projections for the ganglion cell layer–inner nuclear layer were used to identify the FAZ.
Results Preterm children had significantly smaller FAZ diameters than controls (p<0.0001). The foveal pits of preterm children were significantly shallower and less steep (p<0.0001) and total retinal thickness at the fovea was significantly increased (p<0.0001) compared to controls. The ganglion cell layer–inner plexiform layer and outer nuclear layer were significantly (p≤0.0001) thicker in preterm children than in controls.
Conclusions Preterm birth results in abnormal foveal vascularisation, a failure of the inner retinal neurons to migrate away from the fovea, and an elevated outer nuclear layer ratio. The spatial coincidence of inner retinal and vascular abnormalities in preterm children supports the hypothesis that aspects of foveal development are interdependent.
- Foveal avascular zone
- colour vision
- visual perception
- diagnostic tests/investigation
- child health (paediatrics)
- visual perception
Funding Supported by a Fight For Sight Postdoctoral Fellowship, Gerber Foundation, One Sight Foundation, and Once Upon a Time Foundation.
Competing interests None.
Ethics approval This study was approved by the Institutional Review Board of the University of Texas Southwestern Medical Center (Dallas, TX).
Provenance and peer review Not commissioned; externally peer reviewed.