学龄儿童周边眼轴长度及视网膜曲率与屈光状态的关联性

Association of peripheral axial length,retinal curvature with refraction in school-aged children

目的探索学龄儿童周边眼轴长度及视网膜曲率半径与屈光状态之间的关联性。方法采用横断面研究设计,纳入2021年7-10月于首都医科大学附属北京同仁医院进行眼科检查的6~15岁儿童287人287眼,其中男154人,女133人。采用标准对数视力表测定受检眼裸眼视力及最佳矫正视力;采用复方托吡卡胺滴眼液点眼行睫状肌麻痹,采用电脑验光仪测量等效球镜度(SE)。根据SE不同将受检者分为远视组90眼、正视组82眼和近视组115眼,分别为SE>+0.5 D、SE>-0.5 D~≤+0.5 D和SE≤-0.5 D。采用Lenstar LS900分别测量受检者中央和周边30°颞侧、鼻侧、上方、下方眼轴长度。采用部分相干光测量建模法计算视网膜坐标并转化为视网膜曲率半径。根据水平方向(鼻颞侧)周边眼轴长度差值绝对值(中位数)作为临界值将受检眼分为H1组(眼轴长度差值<0.35 mm)和H2组(眼轴长度差值≥0.35 mm);根据垂直方向(上下方)周边眼轴长度差值绝对值(中位数)分为V1组(眼轴长度差值<0.32 mm)和V2组(眼轴长度差值≥0.32 mm)。依据上述水平和垂直方向分组方法将受检眼分为V1H1、V1H2、V2H1和V2H2组。比较不同组间受检者眼轴长度、SE、近视比例和视网膜曲率半径。结果受检眼中央眼轴长度为23.53(22.93,24.10)mm。颞侧、鼻侧、上方、下方周边眼轴长度分别为22.75(22.11,23.22)、22.99(22.32,23.45)、23.24(22.58,23.75)和23.12(22.52,23.56)mm,其中颞侧眼轴长度低于鼻侧,差异有统计学意义(Z=-3.58,P<0.01)。H1组中央、鼻侧、上方及下方眼轴长度均较H2组短,V1组中央、鼻侧、上方眼轴长度均较V2组短,差异均有统计学意义(均P<0.05)。H1组SE为+0.06(-1.06,+0.75)D,明显大于H2组的-0.32(-1.64,+0.56)D,差异有统计学意义(Z=-2.10,P=0.04)。V1组SE为+0.13(-0.81,+0.80)D,明显大于V2组的-0.56(-1.83,+0.48)D,差异有统计学意义(Z=-3.39,P<0.01)。V1组近视比例为33.5%(58/173),低于V2组的50.5%(53/105),差异有统计学意义(χ^(2)=7.83,P<0.01)。V1H1、V1H2、V2H1和V2H2组SE总体比较差异有统计学意义(H=24.79,P<0.01),其中V1H1组SE显著大于V1H2组、V2H1组和V2H2组,差异均有统计学意义(均P<0.01)。远视组、正视组、近视组受检眼水平方向和垂直方向视网膜曲率半径总体比较,差异均有统计学意义(H=22.34、19.30,均P<0.01),其中远视组和正视组水平及垂直方向视网膜曲率半径显著大于近视组,差异均有统计学意义(均P<0.01)。结论学龄儿童眼球的周边眼轴长度存在不对称性,不对称程度越高则屈光度越偏向近视。与正视及远视儿童相比,近视儿童的视网膜形态更陡峭。

Objective To investigate the association of peripheral axial lengths and retinal curvatures with refractive status.Methods A cross-sectional study was conducted out.Two hundred and eighty-seven eyes of 287 consecutive children aged 6-15 years old who recieved eye examinations at Beijing Tongren Hospital from July to October 2021 were enrolled,including 154 males and 133 females.Uncorrected and best corrected visual acuity were tested with a standard logarithmic visual acuity chart.Spherical equivalent(SE)was measured via an auto refractometer after cycloplegia with tropicamide.The hyperopic,emmetropic and myopic groups were defined with a SE>+0.5 D,SE>-0.5 D to≤+0.5 D and SE≤-0.5 D,respectively.Central and 30°peripheral eye lengths(nasal,temporal,superior,inferior)were obtained using the Lenstar LS900.Retinal coordinates were derived from partial coherence interferometry modeling and converted to retinal curvatures.According to the median horizontal peripheral eye length differences(absolute difference between nasal and temporal),participants were assigned to H1 group(absolute difference<0.35 mm)or H2 group(absolute difference≥0.35 mm).According to the median vertical peripheral eye length differences(absolute difference between superior and inferior),participants were assigned to V1 group(absolute difference<0.32 mm)or V2 group(absolute difference≥0.32 mm).Four groups of V1H1,V1H2,V2H1 and V2H2 were constructed according to the grouping methods in both directions above.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Beijing Tongren Hospital,Capital Medical University(No.TRECKY2021-162).Written informed consent was obtained from guardians of each subject prior to any medical examination.Results The central axial length was 23.53(22.93,24.10)mm.Peripheral eye lengths of temporal,nasal,superior and inferior were 22.75(22.11,23.22)mm,22.99(22.32,23.45)mm,23.24(22.58,23.75)mm and 23.12(22.52,23.56)mm,respectively.Temporal eye length was shorter than nasal,showing a statistically significant difference(Z=-3.58,P<0.01).Compared with H2 group,H1 group had shorter central,nasal,superior and inferior eye lengths,showing statistically significant differences(all at P<0.05).Compared with V2 group,V1 group had shorter central,nasal and superior eye lengths,showing statistically significant differences(all at P<0.05).SE of H1 group was+0.06(-1.06,+0.75)D,which was significantly greater than-0.32(-1.64,+0.56)D of H2 group(Z=-2.10,P=0.04).SE of V1 group was+0.13(-0.81,+0.80)D,which was significantly greater than-0.56(-1.83,+0.48)D of H2 group(Z=-3.39,P<0.01).The myopia ratio of V1 group was 33.5%(58/173),which was significantly lower than 50.5%(53/105)of V2 group(χ^(2)=7.83,P<0.01).There was a significant overall difference in SE among VIH1,V1H2,V2H1 and V2H2 groups(H=24.79,P<0.01).SE was greater in V1H1 group than V1H2,V2H1 and V2H2 groups(all at P<0.01).There was a significant difference in both horizontal and vertical retinal curvatures among different refractive groups(H=22.34,19.30;both at P<0.01).The retical curvature in both directions of hyperopic and emmetropic groups were significantly larger than those of myopic group(both at P<0.01).Conclusions Peripheral eye lengths are asymmetric in school-aged children.Higher asymmetry is associated with myopic shifts.Myopic children have a steeper retina than the hyperopic and emmetropic children.