Long-Term Multimodal Imaging Analysis of Selective Retina Therapy Laser Lesions

Abstract

This study evaluates the long-term effects of selective retina therapy (SRT) on the retinal pigment epithelium (RPE) and neuroretina in patients with central serous chorioretinopathy. SRT was performed on 36 patients using a Nd:YLF-Laser at 527 nm (R:GEN®, Lutronic, Goyang-Si, Republic of Korea). A total of 994 titration spots were examined using up to three years’ multimodal imaging. Leakage in fluorescein angiography (FA) was observed after SRT in 523 lesions and resolved after one month. SRT lesions were not visible clinically, but appeared as brightly reflective areas in infrared and multicolor images. Normal morphology was observed in optical coherence tomography (OCT) immediately after SRT. After one month, thickening of the RPE and interdigitation zone changes were seen and disappeared after 539 ± 308 days. No RPE atrophies occurred during the observation period. Decreased fundus autofluorescence (FAF) was mostly observed directly after SRT followed by increased FAF at one month, which faded over time. A significant decrease in the number of visible lesions in the FA and FAF was observed within the three-year follow-up. OCT findings are consistent with animal studies showing SRT-related defect closure by hypertrophy and migration of neighboring cells without RPE atrophy or photoreceptor damage. This suggests that SRT is a safe treatment option for macular diseases and does not lead to retinal atrophy.

Real-time OCT feedback-controlled RPE photodisruption in ex vivo porcine eyes using 8 microsecond laser pulses

“…However, within the single pulse and RFD sample regions, we found no immediate change in reflectivity in this experiment. The same was already observed by us [ 48 – 50 ] as well as by Binter et al in patients treated with SRT [ 85 ]. In their study, SRT lesions appeared after one week in IR images.…”

“…In their study, SRT lesions appeared after one week in IR images. This observation is related to local hyperreflectivity and thickening at the level of the RPE in OCT B-scan images, possibly indicating focal proliferation [ 85 ] of the RPE in the process of lesion closure after laser treatment (RPE rejuvenation). The changes in OCT morphology decreased and normalized within 6 months, and the neurosensory retinal layers, including the outer photoreceptor layers, appeared to be largely unaffected in all SRT lesions.…”

Real-time OCT feedback-controlled RPE photodisruption in ex vivo porcine eyes using 8 microsecond laser pulses

“…However, within the single pulse and RFD sample regions, we found no immediate change in reflectivity in this experiment. The same was already observed by us [37][38][39] as well as by Binter et al in patients treated with SRT [72]. In their study, SRT lesions appeared after one week in IR images.…”

“…In their study, SRT lesions appeared after one week in IR images. This observation is related to local hyperreflectivity and thickening at the level of the RPE in OCT B-scan images, possibly indicating focal proliferation [72] of the RPE in the process of lesion closure after laser treatment (RPE rejuvenation). The changes in OCT morphology decreased and normalized within 6 months, and the neurosensory retinal layers, including the outer photoreceptor layers, appeared to be largely unaffected in all SRT lesions.…”