Central corneal thickness and intraocular pressure in premature infants

To evaluate the central corneal thickness (CCT) and intraocular pressure (IOP) of premature infants and to document correlation of them with gestational age, chronological age, and birth weight of infants. Using a hand-held applanation tonometer and a portable pachymeter, IOP and CCT of 170 premature infants were measured just before initial retinopathy of prematurity screening examination and re-measured 4 weeks after the first visit. The CCT and IOP were positively correlated during the first (r = 0.616, p < 0.001) and second (r = 0.564, p < 0.001) visits. The mean CCT at first and second visits were 568.1 ± 22.1 (527–628) and 561.6 ± 21.4 (520–619) µm, consecutively (p < 0.001). Gestational age, chronological age and birth weight of infants were found to be negatively correlated with CCT at first (r = −0.751, p < 0.001; r = −0.745, p < 0.001; r = −0.581, p < 0.001, consecutively) and second (r = −0.729, p < 0.001; r = −0.729, p < 0.001; r = −0.555, p < 0.001, consecutively) visits. The mean IOP at first and second visits were 14.1 ± 1.9 (11–19) and 13.7 ± 1.7 (11–18) mmHg, consecutively (p < 0.001). Gestational age, chronological age, and birth weight of infants were found to be negatively correlated with IOP at first (r = −0.724, p < 0.001; r = −0.715, p < 0.001; r = −0.558, p < 0.001, consecutively) and second (r = −0.704, p < 0.001; r = −0.703, p < 0.001; r = −0.518, p < 0.001, consecutively) visits. CCT and IOP of the premature infants with a smaller gestational age were found to be higher (p < 0.001 for both). Premature infants with smaller gestational age have higher CCT and IOP values when compared to older infants. These values tend to become lower 4 weeks after the first examination as infants become older. The CCT and IOP were positively correlated with each other and both were negatively correlated with gestational age, chronological age, and birth weight during first and second visits.