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.

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.

Purpose: To analyze and classify neurofibromatosis Type 1 (NF1)-related retinal vascular abnormalities (RVAs), their natural history and correlation with disease severity, in a large cohort of patients. Methods: This was an observational longitudinal study with prospective enrollment. Four hundred and seventy-three patients affected by NF1 and 150 age-matched healthy subjects were consecutively enrolled. Retinal vascular abnormalities were detected by means of near-infrared reflectance and studied by optical coherence tomography angiography. The superficial vascular plexus and the deep vascular complex (DVC) were quantitatively and qualitatively analyzed. Results: We identified RVAs in 82 of 473 (17%) NF1 patients, but in none of the 150 healthy subjects. A comparison revealed that NF1 patients with RVAs showed a higher number of NF1 diagnostic criteria (4.3 ± 1.5 vs. 3.9 ±1.5, respectively; P = 0.02) than patients without RVAs. Three different RVA types were identified on optical coherence tomography angiography: macrovascular angiomatosis of the sole superficial vascular plexus; macrovascular angiomatosis of the superficial vascular plexus combined with microvascular angiomatosis of the deep vascular complex; and combined macrovascular angiomatosis of both superficial vascular plexus and deep vascular complex. The prospective analysis of optical coherence tomography angiography images showed no significant longitudinal evolution of RVAs (mean follow-up: 3.7 ± 2.8 years). A single patient developed a de novo single RVA, and two RVAs showed detectable changes during follow-up. Conclusion: In NF1 patients, RVAs are a characteristic sign that correlates with a more severe systemic disease expression, usually remaining stable during time. Optical coherence tomography angiography allows for the identification of different RVAs subtypes.