Subthreshold lasers operate below the threshold of visible tissue damage, thereby preventing ophthalmoscopically visible thermal damage to the chorio-retinal layers. They could represent a safe and effective alternative and/or adjunctive procedure to conventional lasers in treating diabetic macula edema (DME), central serous chorioretinopathy (CSCR), and branch retina vein occlusion (BRVO). This review focuses on the use of subthreshold micropulse laser (SMPL), its settings, and clinical applications. Despite their widespread use, a standardized protocol for sub-threshold laser settings has not been established yet, and thus, there is uncertainty in selecting effective and safe parameters for any specific situation. We conducted a comprehensive overview of the existing indications for subthreshold laser therapy and their settings for different retinal diseases. The debate revolves around which parameters could guarantee the safety of the procedure for each case, depending on the duty cycle, the laser wavelength, the spot duration, and the power, with laser power titration on one side or choosing a fixed lowered power value on the other side. SMPL therapy for DME, CSCR, and BRVO-associated macular edema has shown significant effectiveness in reducing the macular thickness, facilitating subretinal fluid absorptions, increasing the best corrected visual acuity (BCVA) and reducing the number of intravitreal injections (IVI) required annually. We presented a broad list of the laser parameters reported in the literature, organized into different tables divided based on the specific pathology, with the aim of providing a useful tool for future studies.

The purpose of this study was to summarize the results related to ocular biometry performed using swept-source optical coherence tomography (SS-OCT). A literature search was conducted to search articles reporting the clinical outcomes of patients who underwent examinations with commercially available SS-OCT machines. The available data were thoroughly analyzed, with a particular focus on all the biometric factors used to calculate the power of intraocular lenses (IOLs) implanted during cataract surgery. The agreement, repeatability, and reproducibility of several parameters among different devices were examined. The variations found for parameters obtained from agreement testing were evaluated in order to promote the interchangeability of devices. Swept-source optical coherence tomography biometers usually produce highly repeatable and reproducible results. The excellent results obtained led us to the conclusion that optical biometers based on SS-OCT technology will probably take the lead in ocular biometry.

Purpose: To assess the long-term outcomes of transepithelial iontophoresis cross-linking (I-CXL) for early keratoconus with high visual acuity under the age of 25. Methods: This retrospective study was conducted at the Department of Ophthalmology, Humanitas San Pio X, Milan, Italy, on data collected between 2015 and 2020. Patients diagnosed with early keratoconus and under the age of 25 who underwent to I-CXL were retrospectively reviewed and included in the study if they fulfilled the following criteria: high visual acuity (LogMAR ≤ 0.2) before I-CXL and the fact that the fellow, most advanced eye, had been treated with epithelium off CXL (S-CXL). Corrected distance visual acuity (CDVA), spherical equivalent refraction, thinnest corneal thickness, corneal topography and tomography were assessed at baseline and at least 24 months of follow-up, using Pentacam. Statistical analysis was performed with STATA SE version 17. Results: Twenty patients with a mean age of 18.5 ± 3.75 months were included. The median follow-up time was 24 months. The statistical analysis showed no significant change over time in CDVA, maximum keratometry and A, B, C values of the Belin Progression Display. Mean baseline CDVA was 0.03 ± 0.07 logMAR, whereas at 24-month was 0.01 ± 0.04. Mean spherical equivalent was − 1.29 ± 1.38D at baseline and − 1.05 ± 1.51D after 24 months. Preoperative maximum keratometry was 48.35 ± 4.95 D and 48.56 ± 4.96 D after the 2 years of follow-up. Mean baseline A value was 7.13 ± 1.66 mm and 24-month postoperative was 7.43 ± 0.48 mm. Average B value was 5.87 ± 0.55 mm prior to surgery, while it was 5.83 ± 0.60 mm after the last follow-up. Mean baseline and 24-month thinnest point were 498.9 ± 34.29 μm and 500.10 ± 33.45 μm respectively. None of the patients showed a progression of keratoconus. Conclusion: I-CXL may be considered as a beneficial treatment option for young patients with less advanced keratoconus, although further consensus on patient selection criteria is needed.