To compare the efficacy and safety of subthreshold micropulse laser (SML) with threshold conventional laser (TCL) in central serous chorioretinopathy (CSC). Prospective, randomized, double-masked, non-inferiority, 12-week clinical trial. Patients were randomly assigned 1:1 to SML group or TCL group. Patients in the SML group were treated with 577 nm micropulse laser. The spot size was 160 µm, the duty cycle was 5% and exposure time was 0.2 s. The power was 50% threshold tested. Patients in the TCL group were treated with 577 nm continuous laser. The power was 100% threshold tested. The primary outcome was the mean change in best-corrected visual acuity (BCVA) at week 12, with a non-inferiority limit of five letters on the Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity charts. Eighty-eight patients were enroled. Seventy-seven patients were male. Forty-four patients were in SML group and 44 in TCL group. At week 12, SML was equivalent to TCL with a gain of 6.23 ± 8.59 and 6.61 ± 6.35 letters, respectively, (SML–TCL difference: −0.38 letters; 95% confidence interval (CI):−3.58–2.81; Pnon-inferiority = 0.0026). There was no statistically significant difference between the two groups (t = 0.240, P = 0.811). At week 12, the proportion of patients whose SRF had been totally absorbed was 63.63 and 81.82% respectively for SML and TCL groups. There was no statistically significant difference between the two groups (χ2 = 3.67, P = 0.056). Both SML and TCL can improve visual acuity in CSC. SML was non-inferior to TCL in the improvement of BCVA.

中文翻译：

---

亚阈值微脉冲激光与阈值常规激光治疗中央浆液性脉络膜视网膜病变的疗效和安全性

比较亚阈值微脉冲激光 (SML) 与阈值常规激光 (TCL) 治疗中央浆液性脉络膜视网膜病变 (CSC) 的疗效和安全性。前瞻性、随机、双盲、非劣效性、12 周临床试验。患者按 1:1 随机分配至 SML 组或 TCL 组。SML 组患者接受 577 nm 微脉冲激光治疗。光斑尺寸为 160 µm，占空比为 5%，曝光时间为 0.2 秒。功效经过 50% 阈值测试。TCL组患者接受577 nm连续激光治疗。功效经过 100% 阈值测试。主要结果是第 12 周时最佳矫正视力 (BCVA) 的平均变化，早期治疗糖尿病视网膜病变研究 (ETDRS) 视力图表上的非劣效性限制为五个字母。招募了八十八名患者。七十七名患者为男性。SML组44例，TCL组44例。第 12 周时，SML 与 TCL 等效，增益分别为 6.23 ± 8.59 和 6.61 ± 6.35 个字母（SML-TCL 差异：-0.38 个字母；95% 置信区间 (CI)：-3.58-2.81；P 非劣效性） = 0.0026）。两组间无统计学差异（t = 0.240，P = 0.811）。第12周时，SML组和TCL组SRF完全吸收的患者比例分别为63.63%和81.82%。两组间差异无统计学意义（χ2 = 3.67，P = 0.056）。SML 和 TCL 均可提高 CSC 的视力。SML在改善BCVA方面不劣于TCL。SML 相当于 TCL，增益分别为 6.23 ± 8.59 和 6.61 ± 6.35 个字母（SML-TCL 差异：-0.38 个字母；95% 置信区间 (CI)：-3.58-2.81；Pnon-inferiority = 0.0026）。两组间无统计学差异（t = 0.240，P = 0.811）。第12周时，SML组和TCL组SRF完全吸收的患者比例分别为63.63%和81.82%。两组间差异无统计学意义（χ2 = 3.67，P = 0.056）。SML 和 TCL 均可提高 CSC 的视力。SML在改善BCVA方面不劣于TCL。SML 相当于 TCL，增益分别为 6.23 ± 8.59 和 6.61 ± 6.35 个字母（SML-TCL 差异：-0.38 个字母；95% 置信区间 (CI)：-3.58-2.81；Pnon-inferiority = 0.0026）。两组间无统计学差异（t = 0.240，P = 0.811）。第12周时，SML组和TCL组SRF完全吸收的患者比例分别为63.63%和81.82%。两组间差异无统计学意义（χ2 = 3.67，P = 0.056）。SML 和 TCL 均可提高 CSC 的视力。SML在改善BCVA方面不劣于TCL。两组间无统计学差异（t = 0.240，P = 0.811）。第12周时，SML组和TCL组SRF完全吸收的患者比例分别为63.63%和81.82%。两组间差异无统计学意义（χ2 = 3.67，P = 0.056）。SML 和 TCL 均可提高 CSC 的视力。SML在改善BCVA方面不劣于TCL。两组间无统计学差异（t = 0.240，P = 0.811）。第12周时，SML组和TCL组SRF完全吸收的患者比例分别为63.63%和81.82%。两组间差异无统计学意义（χ2 = 3.67，P = 0.056）。SML 和 TCL 均可提高 CSC 的视力。SML在改善BCVA方面不劣于TCL。