Abstract： Objective:To observe the safety and effectiveness of targeted navigation laser with continuous wave threshold power in the treatment of chronic central serous chorioretinopathy (CCSC).Methods:A retrospective clinical study. From November 2018 to June 2020, 28 eyes of 28 patients with CCSC diagnosed in the Eye Hospital of Nanjing Medical University were included in the study. Among them, there were 17 males with 17 eyes and 11 females with 11 eyes; all of them had a monocular disease. The average age of the patients was 36.24±5.14 years, and the average course of the diseases was 4.7±1.3 months. All affected eyes underwent best corrected visual acuity (BCVA), fluorescein fundus angiography, fundus autofluorescence, frequency domain optical coherence tomography and angiography, multifocal electroretinogram (mf-ERG) and micro field inspection. BCVA was carried out using the international standard visual acuity chart, which was converted into the logarithmic minimum angle of resolution (logMAR) visual acuity during statistics. A targeted navigation laser system was used for continuous wave power therapy under the threshold. Two weeks and 1, 3 months after treatment, the same equipment and methods as before treatment were used to perform related examinations to observe the BCVA, subfoveal choroidal thickness (SFCT), foveal retinal thickness (CMT), the mean light sensitivity (MS) in the 10° range of the macular center, and the amplitude density of P 1 wave at ring 1 and 2. The t test was used to compare CMT, SFCT, retinal amplitude density and MS before and after treatment. Results:Before treatment and 2 weeks, 1 and 3 months after treatment, the average logMAR BCVA of the eyes were 0.74±0.16, 0.57±0.16, 0.22±0.05, 0.21±0.06, and the average CMT was 512.33±31.56, 350.40±36.61, 256.49±22.38, 253.45±23.65 μm respectively, the average SFCT was 462.82±25.38, 462.37±39.54, 461.51±29.36, 461.25±34.55 μm, the average MS was 16.32±5.41, 17.53±4.23, 19.52±4.12, 21.35±2.77 dB respectively. At different times before and after treatment, BCVA ( t=6.52, 5.71, 6.01; P=0.00, 0.00, 0.00), CMT ( t=3.08, 6.57, 4.90; P=0.01, 0.00, 0.00), SFCT ( t=7.01, 6.54, 4.85; P=0.08, 0.07, 0.17), MS ( t=6.17, 4.25, 5.46; P=0.02, 0.00, 0.00), the difference was statistically significant. The amplitude density of P 1 wave at ring 1 in the affected eye was 64.37±18.25, 85.31±13.98, 98.35±14.52, 98.40±22.17 nV/deg 2, and the amplitude density of P 1 wave at ring2 was 36.12±18.32, 44.02±17.15, 62.35±14.85, 63.17±15.79 nV/deg 2. The amplitude density of P 1 wave at ring 1 ( t=5.11, 9.03, 4.27; P=0.03, 0.00, 0.00) and ring 2 ( t=5.11, 9.03, 4.27; P=0.03, 0.00, 0.00) before and after treatment showed statistical significance. Conclusion:Targeted navigation laser continuous wave threshold power treatment for CCSC can increase the BCVA, macular retinal amplitude density and macular foveal MS, and reduce CMT and SFCT.