频域OCT对IMH手术前后光感受器内外节与中心凹下脉络膜厚度关系的研究

A pilot study on photoreceptor IS/OS and subfoveal choroidal thickness in IMH with spectral domain OCT

背景Gass理论认为特发性黄斑裂孔（IMH）多由于玻璃体皮质对黄斑区切线方向上的牵拉引起，而频域OCT（SD—OCT）研究发现黄斑区光感受器内外节缺失区直径（DIOA）与患者手术前后的视力有密切关系，但利用深度增强成像（EDI）技术观察IMH患者手术前后DIOA与中心凹下脉络膜厚度（SFCT）的关系，目前尚未见相关报道。目的利用SD—OCT及其EDI技术研究光感受器内节／外节（IS／OS）层和SFCT在IMH手术前后的变化并探讨二者间的关系。方法采用前瞻性研究方法，纳入2011年6月至2013年6月在南方医科大学附属佛山医院眼科中心接受手术治疗的单眼IMH患者40例40眼，患者均由同一位有经验的术者完成23G玻璃体切割术，并由同一操作者采用SD—OCTEDI模式测量患者手术前后水平方向上光感受器DIOA和SFCT，采用Pearson线性相关法分析IMH患者DIOA与SFCT间的关系。结果术后IMH患者中，黄斑裂孔闭合者34眼，裂孔封闭率为85％。术眼术前DIOA平均值为（1280±753）μm，术后6个月为（656±322）μm，手术前后DIOA的差异有统计学意义（t=4．989，P=0．000）。术眼术前平均SFCT为（130±43）μm；术后6个月为（140±38）μm，手术前后SFCT的差异无统计学意义（t=-1．407，P=0．175）。手术前及手术后术眼DIOA与SFCT测量值的变化均呈负相关（术前：r=-0．748，P=0．000；术后：r=-0．686，P=0．001）。结论IMH患者术前和术后6个月时中心凹水平方向上光感受器DIOA与SFCT的变化方向相反，提示IMH患者光感受器IS／OS的变化与脉络膜的血流灌注状态参与IMH的发生。

Background The classical theory from Gass holds that idiopathic macular hole （IMH） is due to the dragging of vitreous cortex in the tangent direction on the macular region,while spectral domain OCT （SD-OCT） studies found that the diameters of inner segment/outer segment （IS/OS） absence （DIOA） region was closely associated with vision ability of IMH patients. Enhanced depth imaging （EDI） is thought to he a new method to study the relation between DIOA and subfoveal choroidal thickness （SFCT） ,but there are few relevant reports. Objective This study aimed to observe the correlation between photoreceptor IS/OS junction and SFCT before and after vitrectomy in IMH by EDI SD-OCT. Methods Forty unilateral IMH patients were enrolled in Affiliated Foshan Hospital of Southern Medical University from June 2011 to June 2013. Vitrectomy （23G） was performed on the patients by the same operator. EDI mode of SD-OCT was used to measure DIOA and SFCT in horizontal direction before and 6 months after surgery. The relationship between DIOA and SFCT was evaluated using Pearson linear correlation analysis. Written informed consent was obtained from each patient before medical assessment. Results IMH was anatomically closed after vitrectomy in 34 eyes with the closure rate 85%. The mean DIOA was （ 1 280± 753）μm in preoperation, which was significantly higher than （ 656 ± 322 ） μm in postoperation （ t = 4. 989, P =0. 000）. The mean SFCT was （130±43）μm in preoperation ,showing a slight reduce in comparison with （140±38）μm in postoperation, but there was not statistical significance between them （ t = - 1. 407, P = 0. 175 ）. Negative correlations were found between DIOA and SFCT in both preoperation and postoperation （preoperation：r=-0. 748 ,P= 0. 000 ;postoperation： r =-0. 686,P = 0. 001 ）. Conclusions The alteration of DIOA shows a negative correlation with SFCT in IMH eyes,suggesting a contributing role of the ehoroid in the change of photoreceptors of IMH.