Department of Ophthalmology, University Vita-Salute, Scientific Institute San Raffaele, Via Olgettina 60, Milan, Italy.
Invest Ophthalmol Vis Sci. 2012 Apr 2;53(4):1783-6. doi: 10.1167/iovs.11-8772.
This study was designed to compare the effects of subthreshold laser treatment (STLT) with threshold laser treatment (TLT) in patients affected by symptomatic retinal arterial macroaneurism (RAM).
Patients affected by symptomatic RAM, characterized by exudative manifestations involving the fovea and best-corrected visual acuity (BCVA) worse than 20/80 Snellen equivalent, were recruited. Patients were randomly assigned to STLT or TLT and regularly followed up for 12 months. Primary outcome measures were changes in central point thickness (CPT) at the end of the follow-up. Secondary outcome measures were changes in mean BCVA at the end of the follow-up and identification of postlaser alterations.
In this single center, randomized, clinical trial, 12 patients were randomized to STLT and 13 to TLT. CPT in STLT was 332 μm at baseline and changed to 249 μm at the 12-month examination. CPT in TLT was 341 μm and reduced to 226 μm at the end of the follow-up. BCVA in STLT changed from 0.72 logMAR to 0.28 logMAR. BCVA in TLT changed from 0.76 logMAR to 0.26 logMAR. The statistical analyses revealed a significant difference comparing the baseline values for both CPT and BCVA in each subgroup from the third month (P < 0.001). No difference was found comparing the two subgroups at any point in time. Three eyes (23%) treated with TLT developed an epiretinal membrane with subjective metamorphopsia.
This pilot randomized clinical trial shows that both STLT and TLT can achieve similar improvements in BCVA and CPT. The lower laser energy delivered by STLT can reduce the complication rate.
本研究旨在比较亚阈激光治疗（STLT）与阈激光治疗（TLT）对症状性视网膜动脉大动脉瘤（RAM）患者的疗效。
纳入患有症状性 RAM 的患者，其特征为出现黄斑区渗出性表现，且最佳矫正视力（BCVA）低于 20/80 视力表等价物。将患者随机分为 STLT 组或 TLT 组，并定期随访 12 个月。主要观察指标为随访结束时中央点厚度（CPT）的变化。次要观察指标为随访结束时平均 BCVA 的变化以及激光治疗后的变化。
在这项单中心、随机、临床试验中，12 例患者被随机分为 STLT 组，13 例患者被随机分为 TLT 组。STLT 组的 CPT 在基线时为 332μm，随访 12 个月时降至 249μm。TLT 组的 CPT 在基线时为 341μm，随访结束时降至 226μm。STLT 组的 BCVA 从 0.72logMAR 变为 0.28logMAR。TLT 组的 BCVA 从 0.76logMAR 变为 0.26logMAR。统计分析显示，在每个亚组中，CPT 和 BCVA 的基线值在第三个月开始就有显著差异（P<0.001）。在任何时间点，两组之间均未发现差异。3 只眼（23%）接受 TLT 治疗后出现视网膜内膜，伴有主观变形。
本初步随机临床试验表明，STLT 和 TLT 均可使 BCVA 和 CPT 得到相似的改善。STLT 传递的较低激光能量可降低并发症发生率。
