Effectiveness, Safety and Choroidal Changes of a Fovea-Sparing Technique for the Treatment of Chronic Central Serous Chorioretinopathy with Yellow Subthreshold Laser

Abstract

The aim of this study was to evaluate the effectiveness and safety of a yellow subthreshold laser (STL) for the treatment of chronic central serous chorioretinopathy delivered in a fovea-sparing pattern and to analyze the post-laser changes in the choroidal structure by Swept-Source Optical Coherence Tomography. This study was a prospective case series of 43 eyes corresponding to 37 patients. Data were recorded at 6, 12 and 24 weeks after the STL treatment. The best-corrected visual acuity improved in 93% of the patients and remained stable in 7%. The subretinal fluid was completely reabsorbed in 27.9%, 32.6% and 69.8% of the patients at 6, 12 and 24 weeks, respectively. There were reductions in the choroidal thickness of 13.1% and 25.3% at 12 and 24 weeks, which corresponded to reductions of 17.5% and 45.9% in the choriocapillaris and Sattler layer and reductions of 12.2% and 21.2% in the Haller layer at 12 and 24 weeks, respectively (p < 0.05). This might account for the effect of the laser on the inner choroidal vasculature, the dysregulation of which is believed to be at the core of central serous chorioretinopathy. No laser-related complications were detected. Overall, the fovea-sparing STL was safe and effective in this series of patients.

Keywords: Haller layer; Sattler layer; Swept-Source optical coherence tomography; central serous chorioretinopathy (CSC); choriocapillaris; choroid; choroidal thickness; pachychoroid disease; yellow subthreshold laser.

Figure 1

Measurements of SRF (a), Haller layer (b) and CT (c). For reference purposes, the Haller layer was not measured exactly under the maximum height of SRF.

Figure 2

Clinical case of a 46-year-old male patient with a 6-month episode of CCSC and an initial BCVA of 20/50 at baseline (a). After STL treatment, we observed a progressive improvement throughout weeks 6 (b), 12 (c) and 24 (d), with a final BCVA of 20/20. In the image the CT, Haller and SRF measures can be appreciated, measured in µm. See Figure 1 for referencing purposes.

Figure 3

Rate of SRF absorption after STL treatment.

Figure 4

Evolution of AF. Images prior STL treatment (a), at 6 weeks (b) and at 24 weeks after STL treatment. Both (b,c) display discrete hyperautofluorescent laser spots near the superotemporal arcades due to the laser titration procedure. The area encompassing the neurosensorial detachment in the central macula does not show any laser-induced changes after receiving a total of 460 spots at the titrated power (see methods section for power titration procedure).