Assessment of the central corneal thickness and intraocular pressure in premature and full-term newborns

PURPOSE: To assess the central corneal thickness (CCT) and intraocular pressure (IOP) in premature and full-term newborns. MATERIALS AND METHODS: In this study, we evaluated measurements of CCT and IOP in 45 premature and 45 full-term newborns. IOP was determined with topical anesthesia using a Tono-Pen AVIA, applanation tonometer and a wire lid retractor in premature newborns undergoing screening for retinopathy. Full-term newborns were used as a control group. CCT was determined with a portable pachymeter after IOP measurements had been made in both groups. Because there was high correlation of CCT and IOP between right and left eyes, only the right eye data were used for further analyses. RESULTS: The mean gestational age was 31.5 ± 2.7 weeks (ranging 25-35 weeks) and the mean age at measurement after birth was respectively 36.3 ± 0.9 weeks (ranging 33-37 weeks) in premature newborns and 38.2 ± 0.7 weeks (ranging 38-41 weeks) and 42 ± 2.2 weeks (ranging 39-46 weeks) in full-term newborns. The mean IOP was 16.2 ± 2.7 mmHg (ranging 10-22 mmHg) in premature and 16.6 ± 2.3 mmHg (ranging 10-22 mmHg) in full-term newborns. The mean CCT was found 600 ± 50 μm (ranging 515-790 μm) in the premature group and 586 ± 48 μm (ranging 475-730 μm) in the full-term group. Mean CCT was greater in premature newborns than in full-term newborns, but the difference between groups was not statistically significant (P = 0.7). Mean IOP measurement in two groups was found very similar and the difference also was not statistically significant (P = 0.27). There was no correlation between IOP and CCT, gestational age, gestational weight, age at measurement, weight at measurement neither right nor left eye in both groups in multiple regression analysis. CONCLUSION: We found that premature infants have slightly thicker corneas but no high IOP measurements than full-term newborns. It could be concluded that in premature at the mean gestational age of 36 weeks CCT is not different from that of full-term newborns.