Significance of serum glutamate acid levels in children with retinopathy of prematurity and its effect on prognosis

Objective To investigate the relationship between serum glutamate levels and severity of retinopathy of prematurity (ROP) in children and its impact on the prognosis. Methods A total of 92 children with ROP who were screened and treated at Henan Provincial Eye Hospital from June 2017 to June 2018 and 50 healthy preterm infants screened at Henan Provincial Eye Hospital were selected for clinical control study.Ninety-two children with ROP were divided into the mild ROP group and the severe ROP group according to the stage of lesions, and they were divided into the progressive group and the spontaneous regression group according to whether the disease was progressive.The severity of ROP and prognosis were analyzed by measuring serum glutamate levels in 1 week and 6 weeks after birth. Results The serum glutamate concentration in the severe ROP group was the highest in the first week after birth[(122.08±14.55) mmol/L] and in the 6th week after birth [(107.13±13.20) mmol/L], followed by the mild ROP group[(98.60±14.48) mmol/L, (85.41±14.49) mmol/L] separately, and the lowest in the control group[(68.52±7.69) mmol/L, (54.97±6.31) mmol/L] separately, and there were significant differences among the 3 groups (all P<0.05). Pearson correlation analysis showed that serum glutamate concentration was positively correlated with the severity of ROP at 1 week and 6 weeks after birth (r=0.869, 0.875, all P<0.05). The levels of serum glutamate at the first week after birth and at the 6th week after birth in the progressive group [(107.18±17.62) mmol/L, (92.94±16.21) mmol/L]were significantly higher than those in the spontaneous regression group[(131.53±10.22) mmol/L, (118.82±8.18) mmol/L], and there were significant differences between the 2 groups (all P<0.05). The area under the curve(AUC) values of serum glutamate concentration at 1 week after birth and 6 weeks after birth were 0.855 and 0.936, respectively, according to the receiver operating characteristic(ROC) curve, while the optimal critical values of serum glutamate concentration at 1 week and 6 weeks after birth were 117.83 mmol/L (sensitivity was 0.909, specificity was 0.728) and 106.69 ng/L (sensitivity was 1.000, specificity was 0.790), respectively. Conclusions The serum glutamate concentration was positively correlated with the severity of ROP infants in 1 week and 6 weeks after birth.The optimal threshold of serum glutamate concentration in 1 week and 6 weeks after birth was more sensitive and specific in predicting the progression of retinopathy, and had higher value in evaluating the prognosis of the infants. Key words: Retinopathy of prematurity; Glutamate; Progression; Prognosis