Corneal diameter in premature infants.

Abstract

The size of the cornea is important in the diagnosis of primary infantile glaucoma. Reference values regarding eyes of premature infants are scarce. Such data are of special importance in areas such as the Middle East where infantile glaucoma is common and often evident already at birth. The authors have measured the horizontal corneal diameter of the eyes of 127 premature Saudi infants with a gestational age between 23 and 36 weeks and a birth weight ranging from 540 g to 4720 g. The corneal diameter ranged from 7*75 mm to 10 mm. The smallest diameter (7.75 mm) was found in an infant with a gestational age of 23 weeks and having a birth weight of 520 g. The largest diameter (10 mm) belonged to two infants with a gestational age of 34 and 35 weeks and a birth weight of 2250 g and 2240 g respectively. Corneal diameter was positively correlated (p<0-001) with gestational age and birth weight. Graphs depicting the regression line of corneal diameter on gestational age and of corneal diameter on birth weight together with the 95% confidence limits for individual values are provided for reference.

Analysis of the horizontal corneal diameter, central corneal thickness, and axial length in premature infants

“…Fundus examinations reveal that the corneas of premature infants (less than 30 gestational weeks) are often blurred, while most infants of over 31 gestational weeks have sufficient corneal clarity. These findings suggest that corneal hydration in premature infants can play an important role in determining the central corneal thickness (13) . Recent studies have shown that corneal thickness in premature babies decreases towards the time of full-term (13,14) .…”

“…These findings suggest that corneal hydration in premature infants can play an important role in determining the central corneal thickness (13) . Recent studies have shown that corneal thickness in premature babies decreases towards the time of full-term (13,14) . Kirwan et al found that babies born at 31 weeks have thick corneas and that a progressive and statistically significant decrease in thickness occurs towards full-term.…”

“…The mean horizontal diameter of the cornea at birth is reported 10-0 mm, and this increases with advancing gestational age and birth weight (12,13) . The mechanism that determines central corneal thickness is not yet fully understood.…”

A Histomorphometric Study of Corneal Endothelial Cells in Normal Human Fetuses

“…Recently, Denis et al (1998) also reported similar results. However, there have been some studies that reported slightly higher value in premature infants (Musarella and Morin, 1985;Al-Umran and Pandol®, 1992).…”

Central corneal thickness and intraocular pressure in premature infants

“…Increased CCT and peripheral corneal thickness in neonates is thought to be related to prolonged eye closure in utero and decreasing thickness after birth is due to better control of corneal hydration [8]. Uva Results are denoted as mean ± SD (minimum-maximum) Int Ophthalmol et al [4] compared the CCT and IOP values in both premature and term infants and they reported that the IOP measurements of premature infants were slightly greater than in term infants because of an increased CCT.…”