The intraocular pressure and central corneal thickness in healthy premature infants

Purpose: To describe the normal values of intraocular pressure (IOP) and central corneal thickness (CCT) in healthy premature infants.

Methods: Infants of <32 weeks' gestational age who underwent screened for retinopathy of prematurity were prospectively enrolled. The same ophthalmologist measured IOP by applanation tonometry and CCT using ultrasonic pachymetry. Infants were divided into four groups according to postconceptional ages (PCA). The mean values of the IOP and CCT were compared by nonparametric statistical tests, and the relationship of the PCA with IOP and CCT were analyzed with correlation tests. Only right eye measurements were analyzed.

Results: A total of 470 infants (mean PCA, 35.94 ± 4.00 weeks) were enrolled. The mean IOP with standard deviation was 16.86 ± 2.93 mm Hg; the mean CCT, 590 ± 58.26 μm. Both IOP and CCT values were found to be significantly higher in infants with lower versus higher PCA (P < 0.001). There was a statistically significant negative linear relationship between the PCA and the values of IOP and CCT, separately.

Conclusions: IOP and CCT values may be higher in infants with lower PCA. Higher IOP values in these infants may be associated with higher CCT values.