Delaying Photodynamic Therapy for CSCR Results in ONL Thinning

Researchers found a dose-response relationship between serous retinal detachment duration and the severity of outer nuclear layer thinning, highlighting the importance of timely intervention following a diagnosis of central serous chorioretinopathy. Photo: Mohammad Rafieetary, OD. Click image to enlarge. Photodynamic therapy (PDT) has consistently shown good efficacy in treating central serous chorioretinopathy (CSCR); however, the influence of treatment timing on outcomes is not yet well understood. Many patients experience a delay of one to two months before receiving treatment, primarily because they have to plan for posttreatment lifestyle modifications associated with photosensitivity caused by verteporfin. A new study in American Journal of Ophthalmology shed light on how clinical outcomes are affected by prolonged serous retinal detachment (SRD) during this waiting period.Included in the retrospective observational analysis were 94 patients (94 eyes) diagnosed with CSCR who received PDT between January 2016 and August 2024 at a university hospital in Japan. The mean age of the cohort was 57.6 years, 19% were female and the baseline BCVA was 0.18 ±0.24 logMAR (20/30 Snellen). Patients underwent standard PDT a median of 35 days (mean 50.8 ±50.2 days) after initial presentation.The data revealed that the outer nuclear layer exhibited significant thinning during the waiting period, with a mean reduction of 1.9 ±4.4μm compared to baseline measurements. Longer waiting times resulted in greater thinning; however, ultimately, the waiting period did not affect 12-month outcomes for SRD remission or BCVA.The researchers stress in their paper that this doesn’t imply that postponing PDT treatment is without consequences; rather, they explained, “This study revealed a dose-response relationship between SRD duration and the severity of outer nuclear layer thinning, as a measurable effect was observed after only one to two months. Therefore,” they continued, “although we found no association between waiting time and treatment outcomes, our results indicated that a waiting period longer than one to two months could negatively impact the neurosensory retina and potentially impair the visual prognosis in patients with CSCR.”The study presents several limitations, the first being its retrospective design that introduces potential biases. Secondly, the study focused solely on BCVA as a measure of visual function, suggesting a need for future research to include more comprehensive evaluations, such as retinal sensitivity and contrast sensitivity. The patient cohort was also drawn from a tertiary referral center, which may not represent the general population.In conclusion, the researchers summarize that while a one- to two-month waiting period for PDT does not appear to compromise efficacy in CSCR patients, “significant outer nuclear layer thinning occurs during this time,” and “caution is warranted against further delays, as they may lead to irreversible loss of the therapeutic benefit derived from PDT.”Click here for the journal source. Funatsu R, Mihara N, Miyake S, et al. Subretinal fluid duration and clinical outcomes in central serous chorioretinopathy: an analysis of time-to-photodynamic therapy. Am J Ophthalmol. November 26, 2025. [Epub ahead of print]. This article was developed by the editorial staff in conjunction with experts in the field. In the process, AI may have been among the editorial tools used to meet the goals of human editors, who approved all content.