Selective retina therapy (SRT) in patients with therapy refractory persistent acute central serous chorioretinopathy (CSC): 3 months functional and morphological results

Abstract

Purpose Central serous chorioretinopathy (CSC) is a disease presenting with detachment of the neurosensory retina and characteristic focal leakage on fluorescein angiography. The spontaneous remission rate is 84% within 6 months. In this study, the efficacy of selective retina therapy (SRT) was examined in patients with therapy refractory persistent acute CSC defined by symptoms for at least 6 months and persistent subretinal fluid (SRF) despite eplerenone therapy. Material and methods This is a prospective, monocentric observational study in 17 eyes (16 patients, mean age 42 years, 2 female). SRT was performed with the approved R:GEN laser (Lutronic, South Korea), a micropulsed 527-nm Nd:YLF laser device, with a train of 30 pulses of 1.7 μs at 100-Hz repetition rate at the point of focal leakage determined by fluorescein angiography (FA) at baseline (BSL). Visits on BSL, week 4 (wk4), and week 12 (wk12) included best corrected visual acuity (BCVA, logMar), central retinal thickness (CRT) on spectral domain optical coherence tomography (SD-OCT), and FA. Statistical analysis was performed by pair-by-pair comparisons of multiple observations in each case with Bonferroni correction for multiple testing. (IBM SPSS Statistics 25®). Results Mean CRT at BSL was 387.69 ± 110.4 μm. CRT significantly decreased by 106.31 μm in wk4 (95%-KI: 21.42–191.2; p = 0.01), by 133.63 μm in wk12 (95%-KI: 50.22–217.03; p = 0.001) and by 133.81 μm (95%-KI: 48.88–218.75; p = 0.001) compared to BSL. Treatment success defined as complete resolution of SRF occurred at wk4 in 7/17 eyes (35.3%) and at wk12 in 10/17 eyes (58.8%). Re-SRT was performed in 7/17 eyes (41.2%) after an average of 107.14 ± 96.59 days. Treatment success after Re-SRT was observed in 4/6 eyes (66.6%, 12 weeks after Re-SRT). Mean BCVA did not change significantly from BSL to any later timepoint after adjusting for multiple testing. Notably, eyes with treatment success showed better BCVA at all timepoints and gained more letters compared to failures. Conclusion Single or repetitive SRT may be an effective and safe treatment in 2 of 3 patients suffering from acute persistent CSC after 6 months of symptoms or more. We observed complete resolution of SRF in around 60% of eyes 12 weeks after first SRT treatment and also 12 weeks after Re-SRT treatment in eyes with persistent or recurrent SRF. Results on the long-term course after SRT are still pending.

The Effect of Selective Retina Therapy with Automatic Real-Time Feedback-Controlled Dosimetry for Chronic Central Serous Chorioretinopathy: A Randomized, Open-Label, Controlled Clinical Trial

“…Although numerous interventions have been introduced to stop this progressive damage and to remove SRF, the optimal treatment option for chronic CSC remains unclear [ 32 ]. SRT has been reported as an alternative treatment option for patients with acute and chronic CSC, with favorable anatomical and functional outcomes [ 19 , 20 , 21 , 22 , 23 ]. In this prospective RCT of the safety and efficacy of RFD-guided SRT in chronic CSC, we did not perform pretreatment FFA, and RFD was used only for dosing the pulse energy.…”

“…Briefly, if an upward-pointing arrow, indicating undertreatment, was shown, the preset pulse energy was increased in 10-µJ steps. If a downward-pointing arrow, indicating overtreatment, was shown, the preset pulse energy was decreased in 10-µJ steps, as previously described [ 22 , 23 , 24 , 25 ]. The surgeon controlled the preset pulse energy until a sideways-pointing arrow, indicating adequate pulse energy, was presented on the screen.…”

“…In previous studies, adequate SRT-spot energy was determined by two therapeutic endpoints including a “visible spot on fundus fluorescein angiography (FFA)” and an “invisible spot on color fundus photography (CFP)” [ 19 , 20 , 21 , 22 , 23 ]. To determine the appropriate pulse energy without using FFA for SRT, real-time feedback-controlled dosimetry (RFD) has been developed and optimized for various macular diseases, including CSC [ 21 , 22 , 23 ], diabetic macular edema [ 24 ], and intermediate age-related macular degeneration (AMD) [ 25 ]. RFD with both optoacoustic dosimetry and reflectometry detects transient microbubbles originating from RPE damage in real time and allows individualized laser settings, ensuring the safety of SRT.…”

Selective retina therapy and thermal stimulation of the retina: different regenerative properties - implications for AMD therapy

“…SRT is a micro pulsed laser irradiation therapy that has been applied at 527 nm, like R:GEN® by Lutronic [ 31 – 33 ], and at 532 nm wavelength, like the experimental laser system by Carl Zeiss Meditec [ 23 , 34 , 35 ]. In this study, we used the 532 nm experimental system, which has been adapted to our murine studies.…”

“…Microbubbles lead to cell membrane rupture, thereby inducing cell death, without a temperature increase in surrounding tissues [ 36 ]. SRT is known for its beneficial effects in central serous chorioretinopathy and diabetic macular edema [ 31 , 37 ]. Dosing of the energy level needed is a concern for macular treatment, but feedback-mechanisms have already been assessed in humans with promising results [ 32 , 33 ].…”