Half-Dose Photodynamic Therapy versus High-Density Subthreshold Micropulse Laser Treatment in Patients with Chronic Central Serous Chorioretinopathy: The PLACE Trial

To compare the anatomic and functional efficacy and safety of half-dose photodynamic therapy (PDT) versus high-density subthreshold micropulse laser (HSML) treatment in patients with chronic central serous chorioretinopathy (cCSC). Open-label, multicenter, randomized controlled clinical trial. Patients with cCSC whose disease had to be confirmed by both clinical characteristics and findings on multimodal imaging. Eligible patients were randomized in a 1:1 allocation ratio. Treatment was evaluated during a follow-up visit, and the same treatment was repeated in patients who still demonstrated subretinal fluid (SRF). The primary end point was the complete disappearance of SRF at the first evaluation visit at 6 to 8 weeks after treatment. As a secondary outcome measure, we assessed this anatomic result at the final evaluation visit at 7 to 8 months after treatment. Other secondary outcomes covered functional improvement and included change in best-corrected visual acuity (BCVA; measured in Early Treatment Diabetic Retinopathy Study [ETDRS] letters), retinal sensitivity (measured using microperimetry), and vision-related quality of life using a validated questionnaire. Between November 2013 and September 2016, 179 patients were included: 89 patients were assigned randomly to half-dose PDT, and 90 were assigned randomly to HSML treatment. At their first evaluation visit, SRF had resolved in 51.2% and 13.8% of patients, respectively (P < 0.001). At their final evaluation visit, a significantly higher percentage of PDT-treated patients demonstrated no SRF (67.2% vs. 28.8%; P < 0.001). Moreover, at the first evaluation visit, the PDT-treated patients showed a significantly higher increase in BCVA (+4.60±6.62 ETDRS letters vs. +1.39±8.99 ETDRS letters; P = 0.011), and a significantly higher increase in retinal sensitivity on microperimetry (+2.01±3.04 dB vs. +0.92±3.65 dB; P = 0.046); however, the improvement in vision-related quality of life was similar (score of +2.87±8.35 vs. +2.56±7.36, respectively; P = 0.800). Half-dose PDT is superior to HSML for treating cCSC, leading to a significantly higher proportion of patients with complete resolution of SRF and functional improvement.