A controlled clinical trial comparing half-dose photodynamic therapy (PDT) vs subthreshold micropulse laser (SMLT) for the management of chronic central serous chorioretinopathy (CSCR) noted significant improvements with either treatment, though resolution was potentially faster with PDT.
Study Design
In this prospective, double-masked, controlled trial, 68 patients with chronic CSCR (>3 months of persistent subretinal fluid due to CSCR) were randomized 1:1 to receive half-dose PDT or SMLT. Patients were recruited between 2017–2020 and followed for 1 year. The primary outcome was complete resolution of subretinal fluid (SRF) on OCT. Response to treatment was assessed at month 1 and then every 3 months until the 1-year endpoint, and the same treatment could be repeated if persistent SRF was present during the follow-up period. Secondary outcomes included change in BCVA, central macular thickness on OCT, microperimetry measures, and responses on the NEI Visual Function Questionnaire to assess vision-related quality of life.
Outcomes
Kaplan-Meier curves revealed significantly faster SRF resolution in the half-dose PDT group compared to the SMLT group (p = 0.016). The half-dose PDT group also had better BCVA at 3 months than the SMLT group (p = 0.03), though this difference did not remain significant at 1 year. Both groups showed significant improvements in BCVA, central macular thickness, and retinal sensitivity on microperimetry at 1 year compared to baseline measurements.
Limitations
Enrolled patients had chronic, rather than acute, CSCR, so these results may not be applicable to all patients with this condition. Given the heterogeneity of the disease, it is also not possible to fully control for differences in disease severity, time course, or prior treatments, which could impact outcome analysis. In addition, the primary outcome of SRF resolution was measured on OCT only and did not include angiographic findings.
Clinical Significance
In this prospective, randomized trial, half-dose PDT achieved faster resolution of SRF and BCVA compared to SMLT in patients with chronic CSCR and SRF. However, improvements in anatomic and visual outcomes were seen overall with either treatment modality. This prospective data may help guide physicians and patients regarding treatment options for CSCR, as both PDT and SMLT appear to be viable options.
Financial Disclosures: Dr. M. Ali Khan discloses financial relationships with Allergan, Apellis Pharmaceuticals, Genentech (Consultant/Advisor); Regeneron Pharmaceuticals (Grant Support).