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Medical records of 75 eyes from 75 consecutive patients with uncomplicated rhegmatogenous retinal detachment (RRD) who underwent pars plana vitrectomy (PPV) were analyzed. Inclusion criteria were patients with RRD who underwent primary 23- or 25-gauge PPV with air, gas, or SiO tamponade and performed by a single surgeon, no use of perfluorocarbon liquids (PFCL) and drainage retinotomy, and follow-up ≥ six months. Exclusion criteria were patients who underwent previous vitreoretinal surgery, proliferative vitreoretinopathy (PVR) more than grade B, giant tears, and encircling band associated with PPV. The main endpoint was the anatomical retinal reattachment rate after a single surgical procedure. Secondary endpoints were best-corrected visual acuity (BCVA), postoperative retinal displacement, and intraoperative and/or postoperative complications. Primary anatomical success was achieved in 97.3% of cases using this modified surgical procedure. Retinal slippage occurred only in 28.2% of patients and it was not observed in all cases of macula-on RRD. The mean logMAR of the BCVA significantly improved in 92% of patients and no intraoperative complications were observed. The results suggest that complete subretinal liquid drainage is not mandatory for all RRD cases treated with PPV and that using PFCL and performing a drainage retinotomy are not essential in eyes with primary RRD and PVR less than grade B. Postoperative positioning after PPV for uncomplicated RRD based on the presence or absence of residual subretinal fluid at the end of surgery could limit the occurrence of postoperative retinal displacement, while promoting patient compliance., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2021 Paolo Chelazzi et al.)

The bilateral filter and its variants, such as the joint/cross bilateral filter, are well-known edge-preserving image smoothing tools used in many applications. The reason of this success is its simple definition and the possibility of many adaptations. The bilateral filter is known to be related to robust estimation. This link is lost by the ad hoc introduction of the guide image in the joint/cross bilateral filter. We here propose a new way to derive the joint/cross bilateral filter as a particular case of a more generic filter, which we name the guided bilateral filter. This new filter is iterative, generic, inherits the robustness properties of the robust bilateral filter, and uses a guide image. The link with robust estimation allows us to relate the filter parameters with the statistics of input images. A scheme based on graduated nonconvexity is proposed, which allows converging to an interesting local minimum even when the cost function is nonconvex. With this scheme, the guided bilateral filter can handle non-Gaussian noise on the image to be filtered. A complementary scheme is also proposed to handle non-Gaussian noise on the guide image even if both are strongly correlated. This allows the guided bilateral filter to handle situations with more noise than the joint/cross bilateral filter can work with and leads to high peak signal-to-noise ratio values as shown experimentally.