Comparative efficacy of subthreshold micropulse laser versus conventional laser therapy in central serous chorioretinopathy

Abstract

Subthreshold micropulse laser (SML) and conventional laser photocoagulation (CLP) have established efficacy in treating central serous chorioretinopathy (CSC), but systematic comparisons of their effectiveness, safety, and long-term outcomes remain lacking.We carried out this retrospective study. A total of 109 eyes from 109 CSC patients were included, with 53 eyes in the conventional laser group and 56 eyes in the SML group. The SML group was treated with a 577-nm wavelength laser, targeting areas of leakage and subretinal fluid (SRF). For patients without identifiable leakage points, the treatment area covered the SRF region. The conventional laser group received single-spot laser treatment with a laser spot reaction of ≤ grade 1, targeting leakage points identified by early-phase fluorescein angiography (FFA). Disease duration, leakage points on FFA, best-corrected visual acuity (BCVA) during follow-up, central macular thickness (CMT), SRF resolution, and safety were analyzed. The mean follow-up duration was 6.90 ± 2.77 months. The conventional laser group had a shorter mean disease duration compared to the SML group (P = 0.002), and there was a significant difference in the distribution of leakage points between the two groups (P = 0.000). At 6 months post-treatment, compared to baseline, the BCVA change was 0.24 ± 0.28 in the CL group (P = 0.02) and 0.19 ± 0.18 in the SML group (P = 0.04). There were no significant differences in BCVA between the two groups at any follow-up time point, though. CMT changes from baseline to final follow-up demonstrated a mean reduction of 228.00 ± 181.01 μm in the CL group versus 176.97 ± 143.39 μm in the SML group (both P < 0.001). No significant differences were observed in mean CMT or final OCT changes between the two groups at any follow-up time point. The complete SRF resolution rates were 83.01% in the conventional laser group and 87.50% in the SML group (P = 0.59).Both SML and CL treatments are safe and effective for CSC. CL therapy is a safe and effective option for patients with acute disease, clearly identifiable leakage points located > 250 μm from the foveal center, while SML is preferable for patients with longer disease duration, unclear leakage points, or leakage points located within 250 μm of the foveal center. Clinical trial number: Not applicable.

Keywords: Central serous chorioretinopathy; Conventional laser; Subthreshold micropulse laser.

Fig. 1

Changes in visual acuity in the two treatment groups. Post-treatment visual acuity measurements demonstrated progressive improvement in both groups. However, no statistically significant differences were observed in mean visual acuity at each follow-up time point or in the final visual acuity improvement between the two groups

Fig. 2

OCT changes in two groups of patients. OCT measurements demonstrated progressive reduction of central macular thickness (CMT) in both groups during the 6-month longitudinal assessment. Intergroup comparisons showed no significant differences CMT outcomes at all follow-up time point or in the final CMT change

Fig. 3

Case Report 1. A 38-year-old male presented with metamorphopsia in the left eye for 10 days. BCVA was 0.52 (Logmar). Fundus examination revealed serous elevation in the posterior pole of the left retina (A). FFA demonstrated a leakage point beyond the 250 μm radius from the foveal center (B). OCT showed neurosensory detachment with a CMT of 863 μm (E). The patient underwent 2-spot CL treatment with 100mw energy. At 1-month follow-up, visual acuity improved to 0.1, with minimal residual subretinal fluid on OCT (CMT 250 μm, F). Three-month follow-up revealed complete resolution of posterior pole retinal elevation (C), absence of leakage points on FFA (D), and complete absorption of subretinal fluid on OCT (CMT 145 μm, G)

Fig. 4

Case Report 2 A 39-year-old female presented with decreased vision in the left eye for 1 month. BCVA was 0.30. Fundus examination showed serous elevation in the posterior pole of the left retina (A). FFA revealed a leakage point beyond the 250 μm radius from the foveal center (B). OCT demonstrated neurosensory detachment with localized RPE detachment and a CMT of 433 μm (E). The patient received SML treatment. At 1-month follow-up, visual acuity improved to 0.6, with minimal residual subretinal fluid on OCT (CMT 330 μm, F). Three-month follow-up showed complete resolution of posterior pole retinal elevation (C) with visual acuity of 0.1. FFA revealed complete resolution of leakage points (D), and OCT demonstrated complete absorption of subretinal fluid (CMT 129 μm, G)