Efficacy and Safety of Subthreshold Micropulse Yellow Laser for Persistent Diabetic Macular Edema After Vitrectomy: A Pilot Study

Abstract

Aim: To examine the effect of subthreshold micropulse yellow laser (SMYL) on best-corrected visual acuity (BCVA), central macular thickness (CMT), and optical coherence tomography angiography (OCT-A) changes in eyes with persistent diabetic macular edema (DME) after pars plana vitrectomy (PPV) for tractional DME (TDME).Patients and Methods: In a comparative study, 95 eyes of 95 consecutive patients with persistent DME were prospectively enrolled. The SMYL group (54 eyes) was treated with SMYL 6 months after PPV, while the control group (41 eyes) was followed up without treatment. BCVA and CMT by OCT were analyzed at baseline and 3 and 6 months. Additionally, parameters such as the vessel density (VD) in the superficial capillary plexus (SCP) and deep capillary plexus (DCP), respectively, and the area of the foveal avascular zone (FAZ) were also evaluated on OCT-A.Results: There were no significant differences between both groups in demographic data. In the SMYL group, mean BCVA was significantly increased [F(2,106) = 17.25; p < 0.001; ηp2 = 0.246] from 51.54 ± 13.81 ETDRS letters at baseline to 57.81 ± 12.82 ETDRS letters at 3 months (p < 0.001) and 57.83 ± 13.95 EDTRS letters at 6 months (p < 0.001), respectively. In comparison to the control group, BCVA values were statistically significantly higher in the SMYL group at 3 and 6 months, respectively. Mean CMT significantly decreased [F(2,106) = 30.98; p < 0.001; ηp2 = 0.368] from the baseline value 410.59 ± 129.91 μm to 323.50 ± 89.66 μm at 3 months (p < 0.001) and to 283.39 ± 73.45 μm at 6 months (p < 0.001). CMT values were significantly lower in the SMYL group (p < 0.001), especially at 6 months follow-up time (p < 0.001) compared with the control group. Parafoveal VD in the SCP and DCP was significantly higher in the SMYL group in comparison to the control group, respectively, at 3-month (SCP p < 0.001; DCP p < 0.001) and 6-month follow-up (SCP p < 0.001; DCP p < 0.001). FAZ area was also significantly smaller in the SMYL group at 6-month follow-up (p = 0.001). There were no adverse SMYL treatment effects.Conclusion: SMYL therapy may be a safe and effective treatment option in eyes with persistent macular edema following PPV for TDME.

Yellow Subthreshold Micropulse Laser in Retinal Diseases: An In-Depth Analysis and Review of the Literature

“…Application of YSML in patients who previously underwent pars plana vitrectomy (PPV) for tractional DME was explored by Bonfiglio et al [ 69 ]. They reported data of a consecutive comparative prospective study on 95 eyes of 95 patients in which 54 eyes were treated 6 months after PPV with YSML and 41 eyes were assigned to the control group only for observation.…”

“…In addition, vessel densities evaluated with OCTA in the SCP and DCP were substantially higher and FAZ significantly smaller in the YSML group. No adverse effects were described in YSML patients [ 69 ].…”

Fluoxetine Protects Retinal Ischemic Damage in Mice

“…The injury of the ischemic tissues is determined not only by the lack of blood supply, but also by the process of reperfusion itself by the generation of free radicals and inflammatory cytokines. The shortage of oxygen and nutrients resulting from I/R injury generates reactive oxygen species, leading to retinal damage and the expression of several pro-inflammatory molecules [ 78 , 79 , 80 , 81 , 82 ]. As for other neurodegenerative diseases, neuroinflammation, elicited by ischemia, represents a key process in glaucoma physiopathology [ 83 ].…”

Quantitative Parameters Relevant for Diabetic Macular Edema Evaluation by Optical Coherence Tomography Angiography

“…After subthreshold micropulse yellow laser (SMYL) treatment in patients with previously treatment-naïve DME, no significant differences were found regarding the PD in the SCP, DCP and choriocapillary plexus (CCP) [ 26 ]. In another study, that evaluated the effect of SMYL on OCTA quantitative parameters in cases with persistent DME after pars plana vitrectomy for tractional DME, it resulted that, at 3-month and 6-month follow-up, the parafoveal density in the SCP and DCP was significantly higher in the SMYL group compared to the patients with DME that were only observed and not treated [ 38 ]. Similarly, it was found that during the first month after subthreshold yellow pattern laser therapy for DME, there was an increase in the mean values of this metric in the DCP [ 39 ].…”