Half Dose Photodynamic Therapy Improves Acuity, Reduces Retinal Thickness in CSCR

Half dose photodynamic therapy can lead to an overall mean improvment in visual acuity (VA) and structural outcomes in patients with chronic central serous chorioretinopathy (CSCR), according to a study published in Eye. 

Researchers conducted a retrospective analysis to describe real-world outcomes of PDT for CSCR in a single center spanning 9 years. They analyzed the data of patients with chronic CSCR who received half dose PDT between 2011 and 2019 where VA and retinal thickness were recorded between baseline visit and first recorded review visit. 

Researchers included 125 eyes of 113 patients (mean age, 55.0±12.1 years; 83 men, 30 women) in the study. All patients underwent standard protocol half-dose PDT, which includes an intravenous infusion of verteporfin given over 10 minutes, at half the standard dose, calculated as 3 mg/m² of body surface area. Patients were evaluated for VA and retinal thickness changes using fundus fluorescein angiogram, optical coherence tomography (OCT) at 24±13 weeks. Patients undergoing treatment with anti-vascular endothelial growth factor (VEGF) therapy were excluded from the study.

At baseline, the mean VA was 0.40±0.31 logMAR. Following PDT, patients experienced a mean visual outcome gain of 0.05 logMAR (P =.005). At baseline the mean retinal thickness was 390±82 µm. After PDT, patients experienced a mean retinal thickness reduction of 66 µm (P <.001). Recurrent CSCR was treated in 17.6% of eyes.

The study highlights that, though no predictors were found for VA change, lower baseline retinal thickness predicted retinal thickness change, suggesting that CSCR with less leakage may respond better to PDT. 

“Outer retinal thinning is often seen in CSCR and is a predominant cause of long-term visual loss,” the researchers explain..

Although the observed improvement in VA was modest, the researchers report that some patients had a significant 3-line gain in vision, supporting the existing guidance that half dose PDT laser be undertaken in CSCR. 

“The results are encouraging that this treatment stops further deterioration [of CSCR] and can improve visual acuity and structural outcomes,” the researchers explain.

The main study limitation is its lack of a placebo control group.