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Intraocular Pressure Values using IcareⓇ Rebound Tonometer and Correlation with Postconceptional Age in Premature
Catarina Monteiro1, Maria Vivas1, Júlio Almeida1
1Hospital Professor Doutor Fernando da Fonseca, Amadora, Portugal.
Insights
Intraocular pressure (IOP) in premature infants measured with the Icare tonometer has a normative range of 9.0-22.1 mmHg. IOP significantly decreases with increasing postconceptional age (PCA) in these infants.
Area of Science:
- Ophthalmology
- Neonatology
- Pediatric Medicine
Background:
- Premature infants often require monitoring for eye conditions like retinopathy of prematurity (ROP).
- Accurate intraocular pressure (IOP) measurement is crucial for managing potential ocular complications in neonates.
- Traditional IOP measurement methods can be challenging in premature infants.
Purpose of the Study:
- To establish a normative range for IOP in premature infants using the Icare rebound tonometer.
- To assess IOP variation over time and its correlation with postconceptional age (PCA).
- To evaluate the advantages of the Icare tonometer for IOP measurement in this population.
Main Methods:
- A prospective, single-center study included premature infants (gestational age <32 weeks) in the NICU.
- IOP was measured with an Icare tonometer during ROP screening and at a two-week interval.
- Measurements continued until 37 weeks PCA or infant discharge.
Main Results:
- Evaluated 34 eyes from 17 preterm infants (mean GA 29.4 weeks).
- Mean IOP was 16.1 ± 6.4 mmHg (median 15.3 mmHg), with a 10th-90th percentile range of 9.0-22.1 mmHg.
- A significant average IOP reduction of 4.8 ± 6.7 mmHg was observed every two weeks of PCA (P=0.0019).
Conclusions:
- The normative IOP range in premature infants using the Icare tonometer is 9.0-22.1 mmHg.
- IOP significantly decreases with advancing postconceptional age in premature infants.
- The Icare tonometer offers a viable method for IOP assessment in neonates.
Purpose:
This study aimedto determine a normative range of intraocular pressure (IOP) values measured with Icare rebound tonometer in premature infants and evaluate IOP variation over time and its correlation with the progression of postconceptional age (PCA). By doing so, we also evaluated advantages of this IOP-measuring method in this population when compared to more traditional methods.
Methods:
We conducted a single-center prospective study that included premature infants (gestational age 32 weeks) who were admitted to the neonatal intensive care unit (NICU) in Hospital Professor Doutor Fernando Fonseca. The study took place between January and December 2021. IOP was measured using Icare tonometer on the occasion of the first retinopathy of prematurity (ROP) screening requested by the NICU and again after a two-week interval if PCA was still 37 weeks. IOP measurements were stopped at 37 weeks or if the infant was discharged. The evaluated outcomes were mean IOP values and their correlation with PCA.
Results:
Thirty-four eyes of 17 preterm infants with a mean gestational age of 29.4 2.3 weeks and a mean birth weight of 1222.9 361.9 gr were evaluated. The mean IOP registered was 16.1 6.4 mmHg, with a median value of 15.3 mmHg. The top 90 percentile was 22.1 mmHg and the bottom 10 percentile was 9.0 mmHg. The average IOP reduction was 4.8 6.7 mmHg (P = 0.0019) within the two-week interval of PCA.
Conclusion:
The mean IOP in premature infants was 16.1 6.4 mmHg and this value significantly decreased by 4.8 6.7 mmHg every two weeks of PCA.
