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A longitudinal study to establish the normative value and to evaluate perinatal factors affecting intraocular
Pak Cheung Ng1, Barbara Sau Man Tam, Cheuk Hon Lee
1Department of Pediatric, Prince of Wales Hospital, the Chinese University of Hong Kong, Hong Kong. pakcheungng@cuhk.edu.hk
Insights
This study establishes a normative intraocular pressure (IOP) range for preterm infants, identifying key perinatal factors influencing neonatal ocular pressure. A percentile chart aids in evaluating infant IOP.
Area of Science:
- Neonatal Ophthalmology
- Perinatal Medicine
- Pediatric Ophthalmology
Background:
- Intraocular pressure (IOP) monitoring is crucial for preterm infants, yet normative data and influencing factors are not well-established.
- Early identification of ocular pressure deviations can prevent long-term visual impairment in vulnerable neonates.
Purpose of the Study:
- To establish a normative range of intraocular pressure (IOP) in preterm infants.
- To identify perinatal factors affecting neonatal IOP during early postnatal weeks.
Main Methods:
- Assessed IOP in 104 preterm infants (median gestational age 29.8 weeks) using a handheld tonometer at multiple postnatal ages.
- Employed mixed-effects models to analyze longitudinal IOP data and identify significant perinatal factors.
Main Results:
- Constructed a percentile chart for preterm infant IOP, showing a decrease with increasing postconceptional age.
- IOP was significantly associated with postconceptional age, mean blood pressure, Apgar score, inhaled corticosteroid use, and high-frequency oscillatory ventilation.
Conclusions:
- Developed a quantitative model and percentile chart for preterm infant IOP, serving as a valuable clinical reference.
- Enables comparison of infant IOP against normative data, facilitating adjustments for critical perinatal factors for accurate evaluation.
Purpose:
To establish a normative range of intraocular pressure (IOP) in preterm infants and to identify important perinatal factors that could affect the IOP during the early weeks of neonatal life.
Methods:
The IOP of 104 preterm infants, with a median (interquartile range) gestational age of 29.8 (28.7-30.9) weeks and birth weight of 1208 (1049-1370) g, were assessed in a university-affiliated tertiary neonatal center. These infants had IOP measured by a handheld tonometer at 1, 4, 6, 8, and 10 weeks of postnatal age. The mixed-effects models were used to evaluate the longitudinal IOP measurements and to identify critical perinatal factors that would significantly affect the ocular pressure.
Results:
A percentile chart of IOP in preterm infants was constructed, and the median (10th-90th percentile) IOP ranged from 16.9 (12.3-21.5) to 14.6 (10.1-19.2) mm Hg at 26.1 and 46.4 weeks of postconceptional age, respectively. The IOP was significantly and negatively associated with postconceptional age (P < 0.001), mean blood pressure (P = 0.01), Apgar score at 1 minute (P = 0.04), and use of inhaled corticosteroids (P = 0.03), but was positively correlated with the commencement of high-frequency oscillatory ventilation (P = 0.01).
Conclusions:
A quantitative statistical model has been developed and a percentile chart of IOP constructed for preterm infants that could be used for future reference. Pediatric ophthalmologists and neonatal clinicians can compare the IOP of preterm infants against this chart and make relevant quantitative adjustments for critical perinatal factors so that the IOP may be properly evaluated, both in healthy and ill infants.
