Subthreshold micropulse yellow (577nm) laser versus intravitreal Ranibizumab in treatment of center involving diabetic macular oedema

Purpose To evaluate the effectiveness of subthreshold micropulse laser as compared to intravitreal injection of ranibizumab in treatment of center involving diabetic macular oedema. Methods A total of 76 eyes of 62 patients with center involving diabetic macular oedema were divided into two groups. Group A received intravitreal injection of ranibizumab while group B received subthreshold micropulse laser with rescue intravitreal injection of ranibizumab. The change from baseline in best correscted visual acuity and central subfield thickness were compared at 3, 6, 9 and 12 months follow-up. Any adverse effects were recorded. Results Group A (n = 34 eyes) experienced a statistically significant improvement in best corrected visual acuity (from 0.32±0.16 Log MAR at baseline to 0.21±0.14 Log MAR at 12 months) (P value =0.006), with a statistically significant reduction in central subfield ghickness (from 352.06±34.34µm to 289.47±58.88 µm) (P value=0.001). Group B (n = 42 eyes), also experienced a statistically significant improvement in best corrected visual acuity (from 0.34±0.22 Log MAR at baseline to 0.13±0.31 Log MAR at 12 months) (P value=0.001), with a statistically significant reduction in central subfield thickness (from 300±47.34µm to 253.12±39.60 µm at 12 months) (P value= 0.009). The mean difference in best corrected visual acuity between the group B and group A was -0.08 Log MAR with a 95% CI ranging from -0.197 to 0.037, which supports the claim of non-inferiority between the two treatment regimens. No adverse effects from subthreshold micropulse laser were recorded in both groups. Conclusion subthreshold micropulse laser with rescue intravitreal injection of ranibizumab was non inferior to intravitreal injection of ranibizumab in treatment of center involving diabetic macular oedema as regards the mean change in best corrected visual acuity.

Changes in entropy on polarized-sensitive optical coherence tomography images after therapeutic subthreshold micropulse laser for diabetic macular edema: A pilot study

Purpose To investigate the dynamics of the healing process after therapeutic subthreshold micropulse laser (SMPL) for diabetic macular edema (DME) using polarization-sensitive optical coherence tomography (PS-OCT). Methods Patients with treatment-native or previously-treated DME were prospectively imaged using PS-OCT at baseline, 1, 2, 3, and 6 months. The following outcomes were evaluated: changes in the entropy value per unit area (pixel2) in the retinal pigment epithelium (RPE) on the B-scan image; changes in the entropy value in each stratified layer (retina, RPE, choroid) based on the ETDRS grid circle overlaid with en face entropy mapping, not only the whole ETDRS grid area but also a sector irradiated by the SMPL; and the relationship between edema reduction and entropy changes. Results A total of 11 eyes of 11 consecutive DME patients were enrolled. No visible signs of SMPL treatment were detected on PS-OCT images. The entropy value per unit area (pixel2) in the RPE tended to decrease at 3 and 6 months from baseline (35.8 ± 17.0 vs 26.1 ± 9.8, P = 0.14; vs 28.2 ± 18.3, P = 0.14). Based on the en face entropy mapping, the overall entropy value did not change in each layer in the whole ETDRS grid; however, decrease of entropy in the RPE was observed at 2, 3, and 6 months post-treatment within the SMPL-irradiated sectors (P < 0.01, each). There was a positive correlation between the change rate of retinal thickness and that of entropy in the RPE within the SMPL-irradiated sector at 6 months (r2 = 0.19, P = 0.039). Conclusion Entropy measured using PS-OCT may be a new parameter that facilitates objective monitoring of SMPL-induced functional changes in the RPE that could not previously be assessed directly. This may contribute to a more promising therapeutic evaluation of DME. Clinical trial This clinical study was registered in UMIN-CTR (ID: UMIN000042420).

Subthreshold Micropulse Laser vs. Conventional Laser for Central Serous Chorioretinopathy: A Randomized Controlled Clinical Trial

Purpose: To investigate the effectiveness and safety of 577-nm subthreshold micropulse laser (SML) on acute central serous chorioretinopathy (CSC).Methods: One hundred and ten patients with acute CSC were randomized to receive SML or 577-nm conventional laser (CL) treatment. Optical coherence tomography and best-corrected visual acuity (BCVA) were performed before and after treatment.Results: At 3 months, the complete resolution of subretinal fluid (SRF) in 577-nm SML group (72.7%) was lower than that in CL group (89.1%) (Unadjusted RR, 0.82; P = 0.029), but it was 85.5 vs. 92.7% at 6 months (unadjusted RR, 0.92; P = 0.221). The mean LogMAR BCVA significantly improved, and the mean central foveal thickness (CFT) significantly decreased in the SML group and CL group (all P &lt; 0.001) at 6 months. But there was no statistical difference between the two groups (all P &gt; 0.05). In the SML group, obvious retinal pigment epithelium (RPE) damage was shown only in 3.64% at 1 month but 92.7% in the CL group (P &lt; 0.001).Conclusions: Although 577-nm SML has a lower complete absorption of SRF compared with 577-nm CL for acute CSC at 3 months, it is similarly effective as 577-nm CL on improving retinal anatomy and function at 6 months. Importantly, 577-nm SML causes less damage to the retina.

Subthreshold Micropulse Laser Modulates Retinal Neuroinflammatory Biomarkers in Diabetic Macular Edema

Subthreshold micropulse laser treatment has become a recognized option in the therapeutic approach to diabetic macular edema. However, some yet undefined elements pertaining to its mechanism of action and most effective treatment method still limit its clinical diffusion. We reviewed the current literature on subthreshold micropulse laser treatment, particularly focusing on its effects on the modulation of retinal neuroinflammation. Subthreshold micropulse laser treatment seems to determine a long-term normalization of specific retinal neuroinflammatory metabolic pathways, contributing to the restoration of retinal homeostasis and the curtailing of local inflammatory processes. Optimized and standardized parameters ensure effective and safe treatment.

Morphological changes of macular soft drusen and drusenoid DPED after subthreshold micropulse laser treatment

AIM: To analyze the morphological changes of macular soft drusen and drusenoid pigmental epithelium detachment (DPED) after subthreshold micropulse laser treatment (SMLT). METHODS: Fourteen patients (20 affected eyes) with soft drusen and DPED clinically confirmed from August 2016 to October 2018, were included in this study. 577 nm yellow laser of SMLT was applied for soft drusen and DPED. The changes of soft drusen and DPED in best corrected visual acuity (BCVA)(LogMAR)and height, diameter and cross-sessional area according to fundus autofluorescence and SD-OCT examinations were observed after SMLT RESULTS: BCVA was not significant difference after treatment of soft drusen (P=0.260), and the DPED (P=0.736) than that of the baseline. Compared with the baseline values, the height and cross-sessional area of soft drusen were reduced at the 6mo after treatment, and the differences were statistically significant (P=0.008, P=0.034). Compared with the baseline values, the differences were not statistically significant in height, diameter and cross-sectional area of DPED after treatment. CONCLUSION: BCVA was not reduced for drusen and DPED after SMLT, however, the height and cross-sessional area of soft drusen was reduced compared with those before treatment, and the differences were not statistically significant in height, diameter and cross-sectional area of DPED before and after treatment. The results indicated that SMLT was effective for soft drusen, but was not effective for short-term treatment of DPED. SMLT caused no damage to the visual acuity in treatment of soft drusen and DPED, but prospective, controlled, large sample and long-term follow-up studies should be required.

Diabetic Macular Edema Treated with 577-nm Subthreshold Micropulse Laser: A Real-Life, Long-Term Study

The aim of this study was to evaluate the long-term efficacy and safety of 577-nm subthreshold micropulse laser (SMPL) treatment in a large population of patients affected by mild diabetic macular edema (DME) in a real-life setting. We retrospectively evaluated 134 eyes affected by previously untreated center-involving mild DME, and treated with 577-nm SMPL, using fixed parameters. Retreatment was performed at 3 months, in case of persistent retinal thickening. Optical coherence tomography (OCT), along with short and near-infrared fundus autofluorescence, were used to confirm long-term safety. At the end of at least one year follow-up, a significant improvement in visual acuity was documented, compared to baseline (77.3 ± 4.5 and 79.4 ± 4.4 ETDRS score at baseline and at final follow-up, respectively), as well as a reduction in the mean retinal thickness of the thickest ETDRS macular sector at baseline. A reduction in the central retinal thickness and the mean thickness of the nine ETDRS sectors was also found, without reaching statistical significance. No patients required intravitreal injections. No adverse effects were detected. This study suggests that 577-nm SMPL is a safe and repeatable treatment for mild DME that may be applied to real-life clinical settings using fixed parameters and protocols.