早产儿角膜和结膜知觉度及其相关因素分析

Analysis of corneal and conjunctival sensitivities and its related factors of premature babies

目的分析早产儿角膜和结膜知觉度及其相关影响因素。方法横断面研究。研究纳入2015年5至9月在浙江大学医学院附属妇产科医院出生的早产儿100例，其中男性51例（51%），女性49例（49%），平均出生胎龄（30.93±1.75）周，平均校正胎龄（33.65±1.53）周，平均出生体重（1 592±336）g。于每日早上8~10点早产儿自然清醒并睁开双眼时使用Cochet-Bonnet触觉测量仪测量单眼的角膜中央和颞侧结膜的知觉度阈值，以连续3次接触眨眼反射阳性的最小尼龙丝长度为最终结果。采用配对t检验比较角膜和结膜知觉度，采用独立样本t检验比较不同性别早产儿眼表知觉度，采用Pearson相关分析及多元线性回归法分析早产儿角膜和结膜知觉度与出生胎龄、出生体重、年龄、校正胎龄的关系。结果早产儿角膜和结膜知觉度分别为（44.85±5.53）mm和（23.50±5.48）mm，差异有统计学意义（t=25.620，P〈0.001）；男性与女性早产儿角膜知觉度差异无统计学意义[（44.80±5.83）mm比（44.90±5.25）mm，t=-0.085，P=0.933]，结膜知觉度差异也无统计学意义[（23.14±5.83）mm比（23.88±5.13）mm，t=－0.673，P=0.502]。早产儿角膜和结膜知觉度显著相关（r=0.676，P〈0.001）；早产儿角膜知觉度与胎龄、出生体重无显著的相关性（r=0.067,P=0.510；r=-0.179，P=0.075），与年龄、校正胎龄有显著的相关性（r=0.238，P=0.017；r=0.679，P〈0.001）；早产儿结膜知觉与胎龄、出生体重、年龄无显著相关性（r=0.078，P=0.439；r=－0.096，P=0.344；r=0.151，P=0.133），与校正胎龄有显著相关性（r=0.490，P〈0.001）；回归分析显示早产儿角膜知觉度（Y1）与校正胎龄（X）呈正相关，其回归方程为Y1=2.45X－37.52；早产儿结膜知觉度（Y2）与校正胎龄（X）亦呈正相关，回归方程为Y2=1.75X－35.41。结论早产儿角膜知觉度大于结膜知觉度，男、女性别间角膜、结膜知觉度无差别。校正胎龄与早产儿角膜知觉度、结膜知觉度相关，随着校正胎龄的增加早产儿的角膜和结膜知觉度逐渐增加。

ObjectiveTo analyse the corneal and conjunctival sensitivities of premature babies and to study the relevant influencing factors.MethodsCross-sectional study. One hundred premature infants born at Women＇s Hospital School of Medicine Zhejiang University between May 2015 and September 2015 were enrolled, among which 51 were male （51%） and 49 were female （49%）, the mean gestational age was （30.93±1.75）w, the mean corrected gestational age was （33.65±1.53）w, the mean birth weight was （1 592±336）g. The thresholds of cornea and conjunctiva of infants＇ left or right eyes were measured with Cochet-Bonnet aesthesiometer at 8-10 o＇clock every morning when they naturally woke up, the minimum length of nylon wire that induced three successive times of eye-blink responses was recorded. Paired sample t test was used to compare the corneal and conjunctival sensitivities, the ocular surface sensitivities of preterm infants of different gender were compared using independent samples t-test, Pearson correlation and multiple linear regression analysis was conducted to analyze the correlation of corneal and conjuncitval sensitivities with gestational age, birth weight, age and corrected gestational age.ResultsThe mean corneal sensitivity was （44.85±5.53） mm and the mean conjunctival sensitivity was （23.50±5.48）mm in premature babies, corneal sensitivity was significantly higher than conjunctival sensitivity （t=25.620, P〈0.001）. No statistical significance was found between male and female preterm infants in corneal sensitivity [（44.80±5.83） mm vs. （44.90±5.25） mm, t=-0.085, P=0.933] and conjunctival sensitivity[（23.14±5.83） mm vs. （23.88±5.13） mm, t=-0.673, P=0.502]. Pearson correlation analysis showed that corneal sensitivity was significantly associated with conjunctival sensitivity in prematurity（r=0.676, P〈0.001）. There was significant correlation between corneal sensitivity and age, corrected gestational age （r=0.238, P=0.017; r=0.679, P〈0.001）, however no significant correlation was found between corneal sensitivity and gestational age, birth weight in preterm infants （r=0.067, P=0.510; r=-0.179, P=0.075）. There was significant correlation between conjunctival sensitivity and corrected gestational age （r=0.490, P〈0.001）, however no significant correlation was found between conjunctival sensitivity and gestational age, birth weight and age in preterm infants （r=0.078, P=0.439; r=-0.096, P=0.344; r=0.151, P=0.133）. Multiple linear regression revealed that corneal sensitivity（Y1） was positively correlated with corrected gestational age（X）, the regression equation was Y1=2.45X-37.52, the conjunctical sensitivity（Y2） was also positively correlated with corrected gestational age（X）, the regression equation was Y2=1.75X-35.41.ConclusionsThe corneal sensitivity is higher than conjunctival sensitivity in premature babies.No statistical significance is found between male and female preterm infants in corneal sensitivity and conjunctival sensitivity. The corneal sensitivity and conjunctival sensitivity are correlated with corrected gestational age in preterm infants. The corneal and conjunctival sensitivities of premature babies tend to increase along with the increase of corrected gestational age.