早产儿视网膜血管化的特点

Characteristics of retinal vascularization in premature infants

目的：研究早产儿视网膜血管化的特点。方法对2009年9月1日至2010年8月31日在广东省妇幼保健院出生或收治的出生体重＜2000 g的早产儿进行眼底筛查和随访。记录研究对象不同纠正胎龄时视网膜的血管化情况。采用Spearman相关分析进行数据处理。结果共入选新生儿231例，完成随访212例，随访率91.8%。其中早产儿视网膜病28例，发生率为13.2%；视网膜完全血管化184例。完成随访者的出生体重[中位数（最小值～最大值）]为1600 g（1000～1900 g），出生胎龄为32.4周（27.0～36.5周）。早产儿视网膜由Ⅰ、Ⅱ至和Ⅲ区先后完成血管化。随着纠正胎龄的增加，各区视网膜血管化率逐渐增加。在纠正胎龄32～周组中，Ⅰ、Ⅱ和Ⅲ区视网膜完全血管化比例分别为87.1%（81/93）、7.5%（7/93）和0.0%（0/93）；纠正胎龄36周后，Ⅰ区视网膜全部完全血管化，Ⅱ和Ⅲ区视网膜完全血管化比例分别在纠正胎龄38周、40周明显增加，纠正胎龄达43周时，Ⅲ区视网膜完全血管化比例为100.0%（24/24）。Spearman相关分析发现，早产儿Ⅱ、Ⅲ区视网膜完全血管化进程与纠正胎龄呈正相关（r值分别为0.690和0.720，P值均为0.000）。早产儿纠正胎龄36周后Ⅰ区视网膜全部血管化，Ⅱ区视网膜完全血管化时的纠正胎龄为38.0周（32.2～40.4周），Ⅲ区视网膜完全血管化时的纠正胎龄为41.0周（36.0～42.6周）。早产儿生后Ⅱ、Ⅲ区视网膜由未完全血管化至完全血管化需2～3周；不同个体生后Ⅱ、Ⅲ区视网膜处于未完全血管化时，纠正胎龄相差约8～10周，Ⅱ、Ⅲ区视网膜完全血管化时，纠正胎龄分别相差约8周和6周。结论早产儿视网膜完全血管化进程个体差异较大。几乎所有早产儿在纠正胎龄达足月以后视网膜才完全血管化，大多数患儿需要随访至纠正胎龄41周。建议对不同纠正胎龄时期的早产儿侧重不同分区的眼底检查。

Objective To determine the characteristics of retinal vascularization in premature infants. Methods A prospective study was carried out which included all premature infants with birth weight〈2 000 g, who were hospitalized in Guangdong Women and Children＇s Hospital from September 1, 2009 to August 31, 2010. Close retinal screening and follow-up were carried out in order to record retinal vascularization at different postconceptional ages. Spearman correlation analysis was performed for statistical analysis. Results A total of 231 infants were enrolled, and follow-up was completed in 212 infants giving a follow-up rate of 91.8%. Twentyeight infants developed retinopathy of prematurity （ROP） resulting in a ROP morbidity of 13.2%, and 184 cases had full retinal vascularization. The median birth weight was 1 600 g （1 000-1 900 g） and the median gestational age was 32.4 weeks （27.0-35.5 weeks）. In the 32-week postconceptional age group, the proportion with full vascularization in ZoneⅠ,ⅡandⅢwas 87.1%（81/93）, 7.5%（7/93） and 0.0%（0/93）,＆amp;nbsp;respectively. In the 36-week postconceptional age group, full vascularization was observed in ZoneⅠ, and the proportion with full vascularization in ZoneⅡandⅢrose sharply at 38-week and 40-week postconceptional age, respectively. The proportion with full vascularization in ZoneⅢwas 100.0%（24/24） at 43-week postconceptional age. According to Spearman correlation analysis, there was a positive correlation between ZoneⅡand Zone Ⅲ retinal vascularization progression and postconceptional age （r=0.690 and 0.720;P=0.000）. In premature infants, full retinal vascularization in ZoneⅠoccurred at 36-week postconceptional age. The median gestational age for ZoneⅡand ZoneⅢretinal vascularization was 38 weeks （32.2-40.4 weeks） and 41 weeks （36.0-42.6 weeks）, respectively. Therefore, a further 2-3 weeks were required for full retinal vascularization in ZoneⅡand ZoneⅢ. The time differences for undervascularization in ZoneⅡandⅢwere 8 to 10 weeks, and the time differences for full vascularization in ZoneⅡandⅢwere 8 weeks and 6 weeks, respectively. Conclusion Retinal vascularization varies in premature infants. Almost all premature infants complete vascularization by term gestational age and the majority of infants need to be followed up to 41 weeks. It is essential to focus on the different retinal regions during maturation.