Efficacy of nanosecond laser treatment in central serous chorioretinopathy with and without atrophy of retinal pigment epithelium

Background To evaluate the outcomes of subthreshold nanosecond laser treatment of chronic central serous chorioretinopathy (CSC) as a function of the severity of concomitant of retinal pigment epithelium (RPE) defects. Methods This retrospective study compares data from 23 CSC diagnosed eyes with only mild RPE defects (group 1), 16 CSC eyes with moderate RPE defects (group 2), and 17 CSC eyes having severe RPE defects (group 3). After subthreshold treatment with the standard Ellex 2RT™ nanosecond laser (Ellex Medical Lasers Ltd, Australia), changes in macular structure and levels of subretinal fluid (SRF) were assessed by OCT-SD, OCT-A, functional integrity of the retina was assessed by corrected distance visual acuity (CDVA) and microperimetry, each at baseline and 1, 3, 6, and 12 months after initial treatment; re-treatment took place in cases of persistent SRF pro re nata. Results During the 12 months observation period, group 1 and 2 mostly required on initial and one re-treatment (1.9 ± 1.0 treatments; 1.9 ± 1.3 treatments). In contrast, group 3 was subject to three to four treatments (3.7 ± 1.5 treatments). 6 to 12 months after treatment, subretinal fluid (SRF) disappeared in 100% of the eyes of group 1 and in 76.9%, and 42.9% of the eyes of group 2 and group 3, respectively. Retinal sensitivity and CDVA improved in group 1 and 2, but did not change significantly in group 3 during the 12 months period. Conclusions Subthreshold nanosecond laser treatment is an effective and safe method for the restoration of macular anatomy and sensitivity in acute and chronic CSC cases with only mild or moderate RPE defects. However, this laser treatment has very limited outcome in CSC eyes with more severe RPE defects.