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Growth of the internal and external eye in term and preterm infants
S J Isenberg1, D Neumann, P Y Cheong
1Jules Stein Eye Institute, Department of Ophthalmology, Harbor-UCLA Medical Center, UCLA School of Medicine, USA.
Insights
Newborn eye growth, particularly vitreous chamber depth, is linked to postconceptional age and sex. Lens thickness remains stable in preterm infants during the last trimester and first two postnatal months.
Area of Science:
- Ophthalmology
- Neonatal Medicine
- Pediatric Growth Studies
Background:
- Accurate diagnosis of neonatal ocular disorders like infantile glaucoma and microphthalmos requires understanding external and internal eye growth patterns.
- Certain ocular disorders may selectively impact specific internal eye structures.
- No prior statistical studies have examined internal ocular growth in preterm newborns.
Purpose of the Study:
- To statistically evaluate internal ocular growth in healthy preterm and term newborns.
- To determine the correlation between postconceptional age and key ocular measurements.
- To investigate sex-based differences in ocular growth patterns.
Main Methods:
- A-scan ultrasonography was used on 101 healthy preterm and term newborns.
- Measurements included axial length, anterior chamber depth, lens thickness, and vitreous chamber depth.
- Correlation and regression analyses were employed to assess growth patterns.
Main Results:
- At term, mean measurements were axial length (16.2 mm), anterior chamber depth (2.0 mm), lens thickness (3.8 mm), and vitreous chamber depth (10.5 mm).
- Postconceptional age significantly correlated with axial length, anterior chamber depth, and vitreous chamber depth, but not lens thickness.
- Regression analysis indicated faster eye growth in males than females, primarily due to increased vitreous chamber depth.
Conclusions:
- Lens thickness remains constant during the last trimester and the first two postnatal months.
- Both anterior and vitreous chamber depths increase during this period, with significant deepening in the vitreous chamber.
- These findings provide crucial data for understanding normal ocular development in neonates.
Background:
Better knowledge of the growth patterns of the external and internal eyes of neonates would permit more accurate diagnosis of disorders that affect ocular size such as infantile glaucoma and microphthalmos. Such disorders preferentially may affect certain parts of the internal eye but not other parts. No previous study statistically has evaluated internal ocular growth in preterm newborns.
Methods:
A-scan ultrasonography was applied directly to the corneas of 101 healthy preterm and term newborns to determine axial length, anterior chamber depth, lens thickness, and vitreous chamber depth. The growth of these structures was evaluated by correlation and regression analyses.
Results:
At term, the mean measurements were axial length, 16.2 mm; anterior chamber depth, 2.0 mm; lens thickness, 3.8 mm; and vitreous chamber depth, 10.5 mm. Postconceptional age correlated to axial length (P < 0.001), anterior chamber depth (P = 0.032), and vitreous chamber depth (P < 0.001), but not to lens thickness (P = 0.48). By regression analysis, the eyes of males grew faster than those of females (P < 0.001) mainly due to the vitreous chamber.
Conclusion:
In the last trimester and first 2 postnatal months, lens thickness remains constant, while the anterior chamber and, especially, the vitreous chamber deepen.