Microstructural changes after half-dose photodynamic therapy in patients with chronic central serous chorioretinopathy

Background: To evaluate the retinal and choroidal microstructural changes at fovea after half-dose photodynamic therapy (PDT) in patients with chronic central serous chorioretinopathy (CSC), using optical coherence tomography (OCT). Methods: The study included 35 eyes with unilateral chronic CSC treated with half-dose PDT. The foveal outer nuclear layer (ONL) and subfoveal choroidal thickness (SFCT) in the affected eyes were compared with baseline measurements at month 1, 3, and 6 after half-dose PDT, and those of the healthy contralateral eyes. Results: The mean baseline ONL thickness of the affected eyes was thinner compared to unaffected fellow eyes (66.9 +/- 16.5 mu m vs 111.5 +/- 11.6 mu m, p<0.001), and increased significantly to 68.6 +/- 17.0 mu m at month 3 and 68.9 +/- 17.3 mu m at month 6 after treatment (p = 0.025 and p = 0.014 respectively). The mean baseline SFCT of the affected eyes was thicker compared to unaffected fellow eyes (399.9 +/- 87.0 mu m vs 338.2 +/- 75.4 mu m, p<0.001), and decreased significantly after treatment at month 1, 3, and 6 (374.0 +/- 84.8 mu m, 369.7 +/- 81.8 mu m, 367.3 +/- 80.8 mu m respectively, p<0.001 for all). The responder group (n = 26), in which subretinal fluid was completely resorbed, showed a significant increase in ONL thickness and decrease in SFCT after treatment, whereas in the non-responder group (n = 9) ONL thickness and SFCT did not differ after treatment. Conclusions: In CSC patients, significant changes are observed in foveal ONL thickness and SFCT after half-dose PDT. ONL thickness and SFCT are suggested to be considered in the OCT examinations of CSC patients.

Automated summary

The study revealed significant changes in foveal ONL thickness and SFCT in patients with chronic central serous chorioretinopathy after receiving half-dose PDT. The responder group showed a marked increase in ONL thickness and decrease in SFCT post-treatment, while the non-responder group did not exhibit significant changes in these parameters following treatment.