In this paper, we use Generative Adversarial Networks (GANs) to synthesize high-quality retinal images along with the corresponding semantic label-maps, instead of real images during training of a segmentation network. Different from other previous proposals, we employ a two-step approach: first, a progressively growing GAN is trained to generate the semantic label-maps, which describes the blood vessel structure (i.e., the vasculature); second, an image-to-image translation approach is used to obtain realistic retinal images from the generated vasculature. The adoption of a two-stage process simplifies the generation task, so that the network training requires fewer images with consequent lower memory usage. Moreover, learning is effective, and with only a handful of training samples, our approach generates realistic high-resolution images, which can be successfully used to enlarge small available datasets. Comparable results were obtained by employing only synthetic images in place of real data during training. The practical viability of the proposed approach was demonstrated on two well-established benchmark sets for retinal vessel segmentation—both containing a very small number of training samples—obtaining better performance with respect to state-of-the-art techniques.

Retinitis pigmentosa, defined more properly as cone–rod dystrophy, is a paradigm of inherited diffuse retinal dystrophies, one of the rare diseases with the highest prevalence in the worldwide population and one of the main causes of low vision in the pediatric and elderly age groups. Advancements in and the understanding of molecular biology and gene-editing technologies have raised interest in laying the foundation for new therapeutic strategies for rare diseases. As a consequence, new possibilities for clinicians and patients are arising due to the feasibility of treating such a devastating disorder, reducing its complications. The scope of this review focuses on the pathomolecular mechanisms underlying RP better to understand the prospects of its treatment using innovative approaches.

(1) Objective: To use optical coherence tomography angiography (OCTA) and microperimetry (MP) to evaluate the correlation between retinal structure and function in patients with idiopathic, full-thickness macular holes (FTMHs) (2) Methods: This prospective, observational study included 11 eyes of 10 patients with FTMHs evaluated before surgery using OCTA and MP. MP sensitivity maps were superimposed and registered on slabs corresponding to superficial capillary plexus (SCP) and deep capillary plexus (DCP) on OCTA, and on the outer plexiform layer (OPL) and the Henle fiber layer (HFL) complex in en face OCT. On these maps, mean retinal sensitivity was calculated at 2° and 4°, all centered on the FTMH. Cystic cavity extension was assessed on the slab corresponding to the OPL + HFL complex in en face OCT and DCP in OCTA using the Image J software (Version 1.49v; National Institutes of Health, Bethesda, MD, USA); (3) Results: Absolute scotomas were observed corresponding to the FTMH. Additionally, rings of relative scotoma in the perilesional area were detected and correlated to the cystic spaces on en face OCT and OCTA. There was a significant correlation between reduced retinal sensitivity at 2° and 4° diameters around the FTMH and the extension of cystic areas (p < 0.01). There was a significant correlation between the extension of cystic cavities and BCVA (p < 0.01). (4) Conclusions: Morpho-functional analysis of FTMH using OCTA and MP, and the correlation between vascular abnormalities and impaired retinal sensitivity, may provide new, useful information. This integrated evaluation of FTMH may be useful to determine the function–structure correlation before and after vitreoretinal surgery, in order to gain a better understanding of the functional consequences induced by the morphological alterations, assessing outcomes in a more objective way, and potentially adding new surgical prognostic factors.

Purpose: We investigated the chorioretinal microvascular changes in patients with retinitis pigmentosa (RP) by optical coherence tomography angiography (OCTA). Methods: Twenty-six patients (52 eyes) affected by RP were compared with 19 healthy controls (38 eyes). OCTA 3 mm × 3 mm macular scans were performed in all subjects. We evaluated the vessel density (VD) of the superficial capillary plexus (VD SCP), deep capillary plexus (VD DCP), choriocapillaris (VD CC), and choroid (VD choroid). We also evaluated the foveal avascular zone (FAZ) area, and the correlation between clinical and OCTA parameters. We also measured central retinal thickness (CRT) and subfoveal choroidal thickness (CT). Results: RP patients compared to healthy controls showed significantly lower VD SCP values (27.56% ± 15.37 vs. 49.39% ± 1.55; p-value < 0.0001), lower VD DCP values (38.43% ± 15.23 vs. 3.34% ± 0.26; p-value < 0.0001), lower VD CC values (46.02% ± 1.293 vs. 50.63% ± 0.4274; p-value = 0.0040), and lower VD choroid values (38.48% ± 15.23 vs. 3.34% ± 0.26; p-value < 0.0001). Even the FAZ area was significantly lower in RP patients (0.45 mm² ± 0.35 vs. 0.26 mm² ± 0.13; p-value < 0.0001). The FAZ area was larger with increasing age, both in control (r = 0.42; p = 0.012) and RP group (r = 0.46; p-value = 0.009). In RP patients, there was a statistically significant correlation between best-corrected visual acuity and VD SCP (r = 0.24, p-value = 0.04) and VD DCP (r = 0.52; p-value = 0.0004) and between subfoveal choroidal thickness and VD SCP (r = 0.43, p-value < 0.001) and VD DCP (r = 0.35, p-value < 0.001). Conclusions: In our study, OCTA reported relevant vascular alterations in RP patients in comparison with the healthy controls, in agreement with the published literature. These abnormalities were associated with choroidal atrophy and related to visual acuity loss. OCTA provided clinically significant information and may represent a reliable tool for the management of RP patients.

Inherited retinal dystrophies and retinal degenerations related to more common diseases (i.e., age-related macular dystrophy) are a major issue and one of the main causes of low vision in pediatric and elderly age groups. Advancement and understanding in molecular biology and the possibilities raised by gene-editing techniques opened a new era for clinicians and patients due to feasible possibilities of treating disabling diseases and the reduction in their complications burden. The scope of this review is to focus on the state-of-the-art in somatic cell therapy medicinal products as the basis of new insights and possibilities to use this approach to treat rare eye diseases.

Recently, evidence has supported a significant role for immune and oxidative-mediated damage underlying the pathogenesis of different types of retinal diseases, including retinitis pigmentosa (RP). Our study aimed to evaluate the presence of immune cells and mediators in patients with RP using flow cytometric analysis of peripheral blood (PB) and aqueous humor (AH) samples. We recruited 12 patients with RP and nine controls undergoing cataract surgery. Flow cytometric analysis of PB and AH samples provided a membrane staining that targeted surface molecules (CD14, CD16, CD19, CD3, CD4, CD8, and CD161) identifying monocytes, natural killer (NK) cells, B cells, T cells, and T subpopulations, respectively. Moreover, lymphocytes were polyclonally stimulated to evaluate cytokine (CK) production at single-cell level. The circulating immune cell distribution was comparable between patients with RP and controls. Conversely, in the AH of controls we could detect no cells, while in the RP AH samples we found infiltrating leukocytes, consisting of T (CD3+), B (CD19+), NK (CD16+CD3-) cells, and monocytes (CD14+). In patients with RP, the frequency of most infiltrating immune cell populations was similar between the AH and PB. However, among T cell subpopulations, the frequency of CD3+CD4+ T cells was significantly lower in the RP AH compared to RP PB, whereas CD3+CD4-CD8- double-negative (DN) T cells were significantly higher in the RP AH compared to RP PB. Cytokine production analysis revealed a trend toward an increased frequency of CD3+CD8-CD161+IFN-ɣ-producing cells and a decreased frequency of CD3+CD8+IL-4-producing cells in the RP AH compared to RP PB. The detection of immune cells, particularly DN T cells, and a Th1-skewed phenotype in RP AH suggests immune-mediated and inflammatory mechanisms in the disease.