577nm阈值下微脉冲激光光凝治疗糖尿病黄斑水肿的有效性与安全性研究

The efficacy and safety of 577 nm subthreshold micropulse laser on diabetic macular edema

目的 观察577 nm阈值下微脉冲激光光凝治疗糖尿病黄斑水肿（DME）的有效性和安全性。 方法 回顾性病例系列研究。临床检查确诊的有累及黄斑中心凹的DME患者30例35只眼纳入研究。患者均行最佳矫正视力（BCVA）、眼底彩色照相、荧光素眼底血管造影、光相干断层扫描（OCT）检查。BCVA检查采用早期治疗糖尿病视网膜病变研究（ETDRS）视力表进行。采用日本Topcon公司3D-OCT 2000仪测量黄斑区平均视网膜厚度（ART）、总黄斑体积（TMV）以及ETDRS黄斑9分区的视网膜厚度（RT）、黄斑体积（MV）。患眼平均BCVA为（62.4±10.5）个字母；ART为（327.3±41.2）μm；平均TMV为（9.24±1.17）mm3。患眼均行577 nm阈值下微脉冲激光光凝治疗，光斑直径 200 μm，曝光时间 0.2 s，工作负载系数 5%，治疗能量为阈能量P的6～7倍；治疗后3个月，对仍存在DME的患眼行2次激光光凝，治疗方法同前。治疗后1、3、6个月采用与治疗前相同的设备和方法行相关检查。观察患眼BCVA、ART、平均TMV以及黄斑9分区平均RT、MV变化，外层视网膜（外界膜、椭圆体带、视网膜色素上皮层）的完整性以及并发症发生情况。 结果 与治疗前比较，治疗后1个月BCVA差异无统计学意义（t=1.82，P＞0.05）；3、6个月差异均有统计学意义（t=5.58、7.24，P＜0.05）。治疗后1、3、6个月，患眼ART（t=4.11、4.17、5.96）、平均TMV（t=3.92、4.05、5.80）均下降，差异有统计学意义（P＜0.05）。治疗后6个月，所有区域平均RT（t=3.53、5.07、5.02、4.87、4.94、3.48、4.03、3.17、3.73）、MV（t=3.54、5.16、4.99、4.91、5.05、3.47、4.08、3.10、3.70）均下降，差异有统计学意义（P＜0.05）。随访期间，所有患眼均未观察到可见激光斑、脉络膜新生血管及外层视网膜（外界膜、椭圆体带、视网膜色素上皮层）完整性的缺失。 结论 577 nm阈值下微脉冲激光可以有效促进DME患眼黄斑水肿的吸收，提高BCVA；安全性较高。

Objective To evaluate the clinical efficacy and safety of 577 nm subthreshold micropulse laser on diabetic macular edema （DME）. Methods Retrospective case series study. A total of 30 patients （35 eyes） with centerinvolving DME were enrolled in this study. All the patients received the examinations of best corrected visual acuity （BCVA）, fundus colorized photography, fluorescein fundus angiography （FFA） and optical coherence tomography （OCT）. BCVA was measured by Early Treatment Diabetic Retinopathy Study charts. The average retinal thickness （ART）, total macular volume （TMV） and the retinal thickness （RT） and macular volume （MV） of 9 ETDRS domains were measured by the Japanese Topcon 3D-OCT 2000 instrument. The mean BCVA was 62.4±10.5 letters. The mean ART was 327.3±41.2 μm. The mean TMV was 9.24±1.17 mm3. All patients were treated with 577 nm subthreshold micropulse laser treatment. Subthreshold micropulse laser were performed in the micropulse mode, using a 200 μm spot diameter, a 0.2 s duration with 5% duty cycle and its treatment energy was 67 times of threshold energy. Three months after treatment, re-treatment was performed on patients with incomplete absorption of macular edema. The treatment was the same as before. The BCVA, ART, TMV and the RT and MV of each ETDRS domain were compared and analyzed before and after treatment. The possible complications of micropulse laser treatment were also observed and the safety was evaluated. Results The difference of BCVA were statistically significant in month 3 and month 6 （t=5.58, 7.24; P〈0.05）, but not in month 1 （t=1.82, P〉0.05）. The average CRT （t=4.11, 4.17, 5.96）, CMV （t=3.92, 4.05, 5.80） significantly decreased in 1, 3 and 6 months after treatment, the difference was statistically significant （P〈0.05）. At sixth months, the average retinal thickness （t=3.53, 5.07, 5.02, 4.87, 4.94, 3.48, 4.03, 3.17, 3.73） and retinal volume （t=3.54, 5.16, 4.99, 4.91, 5.05, 3.47, 4.08, 3.10, 3.70） of the 9 ETDRS subdomains significantly decreased, and the difference was statistically significant （P〈0.05）. There was no visible laser spots, changes in the outer retina and complications of neovascularization and subretinal fibrosis in the fundus of all patients. Conclusion577 nm subthreshold micropulse laser can reduce the CMT, CMV and improve the BCVA of DME patients with high security.