AIM: To investigate the efficacy and safety of 577nm subthreshold micropulse laser(SML)in patients with chronic central serous chorioretinopathy(CSC).

METHODS: Prospective single-arm case study. There were 24 patients(32 eyes)with chronic CSC treated by using 577nm SML. A total of 6mo was followed up after treatment, the best corrected visual acuity(BCVA, LogMAR)and optic coherence tomography(OCT)were performed at each month. Fluorescein fundus angiography(FFA)was performed at 1,3 and 6mo after treatment.

RESULTS: The BCVA was 0.46±0.34 and central retinal thickness(CRT)was 259.15±57.54μm of 32 eyes at baseline period. After treatment of SML at 1mo, there was no subretinal fluid in 21 eyes(66%), and subretinal fluid was observed in 11 eyes(34%). The BCVA was 0.43±0.27, the CRT was 232.13±42.58μm. CRT was significantly reduced compared to the baseline period(P<0.05). After treatment of SML at 3mo, subretinal fluid and fluorescein leakage from retinal pigment epithelium(RPE)were observed in 5 eyes(16%). The BCVA was 0.39±0.26 and CRT was 231.26±49.25μm. The CRT was still significantly lower than baseline period(P<0.05). The 5 eyes with subretinal fluid and leaked fluorescein were treated by using SML again. After treatment at 6mo, subretinal fluid was observed in only 3 eyes(9%). The BCVA was 0.19±0.47 and CRT was 217.25±35.54μm. Both of the BCVA and CRT showed a significant improvement from the baseline period(P<0.05).

CONCLUSION:SML seems effective and safe for treatment of chronic CSC. It may be an alternative way for treatment of chronic CSC.