矫正年龄6个月内无早产儿视网膜病变的早产儿眼部生物学参数分析

Analysis of ocular biometric parameters in premature infants with post modification age of less than 6 months and without retinopathy of prematurity

目的探讨矫正年龄(PMA)6个月内的无早产儿视网膜病变(ROP)早产儿眼部生物学参数分布及与出生体重(BW)和PMA的关系。方法纳入490例接受ROP筛查的早产儿并研究。根据PMA分为7组:0个月组(矫正胎龄40周±3 d)、1个月组、2个月组、3个月组、4个月组、5个月组和6个月组。采用RETCAM3检查眼底并排除ROP,角膜测厚仪测量中央角膜厚度(CCT),A超测量眼轴长度(AL)、前房深度(ACD)、晶状体厚度(LT)和玻璃体长度(VL)。利用自动屈光测量仪测量患儿PMA 3个月至6个月非睫状肌麻痹的屈光状态。采用t检验数据正态性,单因素方差分析患儿性别、眼别及组间眼部生物学参数差异性,多因素线性回归模型分析AL、ACD、LT、VL和CCT与BW和PMA的关系。结果入组患儿的出生胎龄为(32.71±2.26)周,BW为(1802.46±480.83)g,ACD、LT、VL、AL、和CCT分别为(2.26±0.30)mm、(4.04±0.24)mm、(11.84±0.84)mm、(18.14±1.11)mm和(535.01±37.63)μm。PMA 3个月至6个月球镜度、柱镜度、等效球镜度(SER)为(+2.19±1.16)D、(-1.71±0.73)D、(+1.38±1.04)D。各年龄组ACD、AL、VL、LT和CCT差异均有统计学意义(均为P<0.01),PMA 3个月至6个月各组间球镜度、SER差异均有统计学意义(均为P<0.05),散光差异无统计学意义(P=0.30)。多因素线性回归方程得出AL、VL和ACD增长与BW和PMA均呈正相关,而其与BW的回归系数分别为0.47、0.34、0.081,与PMA回归系数分别为1.2×10^(-4)、5.4×10^(-5)、6×10^(-5)。LT与PMA呈弱正相关(β=0.06,P<0.01),CCT与PMA呈弱负相关(β=-7.42,P<0.01)。结论PMA和BW是PMA 6个月内无ROP的早产儿AL、VL、ACD的主要影响因素。AL、ACD和VL与BW和PMA均呈正相关。LT与PMA呈弱正相关,CCT与PMA呈弱负相关。无ROP的早产儿生在PMA 3~6个月内远视贮备值逐渐下降,趋于正视化,而散光值在PMA 3~6个月无明显变化。

Objective To explore the distribution of ocular biometric parameters in premature infants with post modification age(PMA)of 40 weeks to 6 months and without retinopathy of prematurity(ROP)and their correlation with birth weight(BW)and PMA.Methods A total of 490 premature infants who underwent ROP screening were enrolled in this study.According to PMA,they were divided into 7 groups:0 month(corrected gestational age:40 weeks±3 days),1 month,2 months,3 months,4 months,5 months,and 6 months.RETCAM3 was used to examine the fundus and exclude ROP.A corneal pachymeter was used to measure the central corneal thickness(CCT).A-mode ultrasound was used to measure the axial length(AL),anterior chamber depth(ACD),lens thickness(LT),and vitreous length(VL).An automatic diopter telescope was used to evaluate the refractive status without cycloplegia in premature infants with PMA of 3-6 months.The data normality was tested by t-test.Differences in gender,left/right eye and ocular biometric parameters were analyzed by one-way ANOVA.The correlation of AL,ACD,LT,VL and CCT with BW and PMA was analyzed by a multivariate linear regression model.Results The average gestational age and average BW of included children were(32.71±2.26)weeks and(1802.46±480.83)g,respectively.The average ACD,LT,VL,AL,and CCT were(2.26±0.30)mm,(4.04±0.24)mm,(11.84±0.84)mm,(18.14±1.11)mm,and(535.01±37.63)μm,respectively.The average sphere,cylinder,and spherical equivalent refraction(SER)of children with PMA from 3 months to 6 months were(+2.19±1.16)D,(-1.71±0.73)D,and(+1.38±1.04)D,respectively.There were significant differences in ACD,AL,VL,LT,and CCT among different age groups(all P<0.01).There were also significant differences in sphere and SER among groups with PMA of 3 months to 6 months(all P<0.05).But there was no significant difference in astigmatism among groups with PMA of 3 months to 6 months(P=0.30).The multivariate linear regression equation showed that the increase of AL,VL and ACD was positively correlated with BW and PMA.Their regression coefficient with BW was 0.47,0.34,and 0.081,respectively,and their regression coefficient with PMA was 1.2×10^(-4),5.4×10^(-5),and 6×10^(-5),respectively.There was a weak positive correlation between LT and PMA(β=0.056)and a weak negative correlation between CCT and PMA(β=-7.42).Conclusion PMA and BW are the main influencing factors of AL,VL and ACD in premature infants(PMA≤6 months)without ROP.AL,ACD and VL are positively correlated with BW and PMA.There is a weak positive correlation between LT and PMA and a weak negative correlation between CCT and PMA.The hyperopia reserve of non-ROP premature infants with PMA of 3-6 months gradually decreases and tends to emmetropia,while the astigmatism has no significant change.