One‐Year Functional and Anatomical Outcomes After Selective Retina Therapy With Real‐Time Feedback‐Controlled Dosimetry in Patients With Intermediate Age‐Related Macular Degeneration: A Pilot Study

Abstract

Background and Objectives This pilot study sought to evaluate changes in macular function and drusen volume (DV) after selective retina therapy (SRT) in patients with intermediate age‐related macular degeneration (iAMD). Study Design/Materials and Methods Twenty participants with bilateral iAMD were included in this prospective interventional case series study. After titrating pulse energy by real‐time feedback‐controlled dosimetry, SRT with a wavelength of 527 nm was applied around the macula of one eye of each patient. Changes in best‐corrected visual acuity (BCVA), DV within the central 5‐mm ring (C5), and retinal sensitivity (RS) of the SRT‐treated eyes (treated eyes) and untreated fellow eyes (untreated eyes) were evaluated at baseline and then at 3, 6, 9, and 12 months after treatment using linear mixed models. Results The mean BCVA did not change significantly between baseline and 12 months in both treated and untreated eyes (P = 0.06, P = 0.24, respectively), whereas the BCVA increase rate was faster for treated than for untreated eyes at the 12‐month visit (–0.072 logMAR; 95% confidence interval [CI], −0.085 to −0.059 logMAR; P = 0.006). The mean cube root transformation of DV (cube root DV) within C5 in the untreated eyes increased significantly from 0.278 ± 0.115 at baseline to 0.295 ± 0.132 mm (P = 0.027) at 12 months, whereas the cube root DV change in treated eyes was not significant (P = 0.553). The rate of increase in the cube root DV was lower in treated than in untreated eyes at the 12‐month visit (−0.016 mm; 95% CI, −0.018 to −0.011 mm; P = 0.015). The mean RS was increased from 22.49 ± 2.40 dB to 24.09 ± 2.19 dB (P < 0.001) in the treated eyes, whereas the change of mean RS in the untreated eyes was not significant at the 12‐month visit (P = 0.18). The treated eyes had a higher rate of increase in RS than untreated eyes at the 12‐month visit (1.012 dB; 95% CI, 0.776–1.251 dB; P = 0.037). The RS change was significantly associated with the interaction between SRT treatment and time (P = 0.028), whereas it was not associated with cube root DV change (P = 0.106). No SRT‐related adverse effects were observed in all participants during the 1‐year follow‐up. Conclusion Since SRT improved the mean RS and reduced the rate of change in drusen load in the treated eyes, as compared to the untreated eyes, SRT might slow the progression of iAMD. However, further large randomized clinical trials are necessary to confirm the efficacy of SRT for iAMD. Lasers Surg. Med. © 2020 Wiley Periodicals LLC

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 the SRT test spots can be clearly detected by FFA in CSC, calculating the RFD accuracy through treatment spots is challenging since SRF at the macular area blurs the leaks from SRT spots when there are overlaps with leaks from spots. As RFD accuracy exceeded 90% based on evaluating test spots in previous reports [ 22 , 25 ], it can be considered that RFD-guided SRT was effective for removing SRF without performing FFA. Since repeated FFA examination could be burdensome for patients because of several side effects, RFD-guided SRT could be useful to waive the need for FFA when treating CSC.…”

“…The physician could determine the preset pulse energy by adjusting the 15th micropulse, as previously described [ 22 , 24 ]. The RFD had fixed thresholds, comprising 2.0 arbitrary units (AU) for the optoacoustic sensor and 6.0 AU for the reflectometry sensor [ 21 , 22 , 24 , 25 ]. The RFD algorithm was programmed to avoid under- and over-treatment: It automatically ceased irradiation immediately for each individual spot when either an optoacoustic value > 2.0 AU, or a reflectometry value > 6.0 AU, was obtained, which we named auto-stop.…”

“…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.…”

“…Although RFD-guided SRT for CSC patients has shown favorable results in previous studies [21,22], pretreatment FFA was used simultaneously for test spots to achieve adequate preset pulse energy. Since the rate of detection of RPE damage by RFD for CSC and intermediate AMD was 95.7% and 93.5%, respectively, SRT using RFD sometimes caused undertreatment rather than overtreatment, such as a burn, as previously reported [22,25]. In this prospective randomized controlled trial (RCT), we evaluated the safety and efficacy of RFD-guided SRT, without pretreatment FFA, in chronic CSC.…”

“…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.…”