频域相干光断层扫描对PASCAL光凝治疗糖尿病性黄斑水肿后视网膜微结构观察

In vivo retinal micro-architecture observation after PASCAL photocoagulation treatment in diabetic macular edema by using spectral-domain optical coherence tomography

目的 通过频域相干光断层扫描（SD-OCT）观察有临床意义糖尿病性黄斑水肿（DME）经PASCAL黄斑区光凝后视网膜微结构变化.方法 13例（15眼）确诊为有临床意义糖尿病性黄斑水肿患者接受PASCAL格栅或局灶激光治疗.所有患者于治疗前1周行荧光素眼底血管造影检查,治疗前及治疗后2h、1周、1个月、3个月均接受散瞳后检眼镜（眼底镜）检查、眼底照相、SD-OCT及最佳矫正视力（治疗后2h除外）检查.结果 治疗前早期治疗糖尿病视网膜病变治疗研究（ETDRS）视力表平均视力47±18字母（27 ～ 80字母）,治疗后3个月平均视力50.5 ±18.0字母（27 ～ 78字母）,治疗前后视力差异无统计学意义（P=0.22）;激光治疗后3个月,黄斑中心凹厚度为（359.9±155.0）μm（275 ～478 μm）,较治疗前黄斑中心凹厚度（409±100）μm （311～643 μm）明显降低（P =0.009）.激光治疗后2h,激光灶表现为视网膜外层柱状中高反射带,部分病灶在外核层表现为向心性倾斜,在外界膜（ELM）平面转而与视网膜色素上皮（RPE）垂直,黄斑区内层结构均未见累及.激光治疗后1周,激光灶处RPE内表面出现颗粒状高反射灶,部分颗粒灶随时间推移完全消失并伴有光感受器内外节连（IS/OS）光带完全修复.激光治疗后3个月,部分颗粒灶仍持续存在甚至扩大,伴有IS/OS光带中断.结论 PASCAL激光短期内可有效改善DME患者黄斑中心凹厚度,对周围正常视网膜结构损伤小,激光灶易于修复,较传统激光更安全.SD-OCT是研究DME患者激光前后视网膜微结构变化的有效手段.

Objective To explore in vivo retinal micro-architecture after PASCAL photocoagulation in diabetic macular edema by using spectral-domain optical coherence tomography （SD-OCT）.Methods In this prospective cohort study,15 eyes of 13 consecutive patients with clinically significant diabetic macular edema underwent grid or focal laser treatment （PASCAL）.Best-corrected visual acuity （BCVA）,SD-OCT,fundus imaging,and biomicroscopy in dilated pupil were performed at baseline,2 hours,1 week,one month and three months after the treatment.Fluorescein angiography was performed at one week before treatment.Results Mean BCVA slightly improved from 47 ± 18 letters （range from 27 to 80 letters） before the treatment to 50.5 ± 18.0 letters （range from 27 to 78 letters） three months after the treatment 3（P =0.22）.Mean central thickness decreased significantly from （409 ± 100） μm （311 ～ 643 μm） at baseline to （359.9 ± 155.0） μm（275 ～ 478 μm） three months after the treatment （P =0.009）.At 2 hours after the treatment,each laser lesion was demarcated as a well defined hyper-reflective column extending through the outer retinal layers,while the inner retinal layers were not affected.Interestingly,some of the hyper-reflective columns appeared as oblique pathway throughout the outer nuclear layer,changing direction at the level of the external limiting membrane （ELM） and proceeding sagittally with retinal pigment epithelium （RPE）.Hyper-reflective deposits were observed in the inner RPE with reduced lesions at one week.Accompanying with the disappearance of the hyper reflective deposits,retinal architecture obtained complete recovery in some laser induced lesions at 3 months after the treatment.However,hyper-reflective deposits in the level of RPE were still observed in other lesions 3 months after treatment,with incomplete retinal repair such as the interrupted inner segment/outer segment （IS/OS） line.Conclusions PASCAL laser photocoagulation can improve the macular central thickness in diabetic macular edema in short duration.PASCAL laser seems safe due to the less damage to the adjacent normal retinal tissues.SD-OCT provides new insight into the retinal micro-architecture changes in vivo after laser treatment using the PASCAL laser system.