Ocular allergy represents one of the most common conditions encountered by allergists and ophthalmologists. Allergic conjunctivitis is often underdiagnosed and consequently undertreated. Basic and clinical research has provided a better understanding of the cells, mediators, and immunologic events, which occur in ocular allergy. New pharmacological agents have improved the efficacy and safety of ocular allergy treatment. An understanding of the immunologic mechanisms, clinical features, differential diagnosis, and treatment of ocular allergy may be useful to all specialists who deal with these patients. The purpose of this review is to systematically review literature underlining all the forms classified as ocular allergy: seasonal allergic conjunctivitis, perennial allergic conjunctivitis, vernal keratoconjunctivitis, atopic keratocongiuntivitis, contact allergy, and giant papillary conjunctivitis.

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Uveal melanoma (UM) represents approximately 5-6% of all melanoma diagnoses and up to 50% of patients succumb to their disease. Although several methods are available, accurate diagnosis is not always easily feasible because of potential accidents (e.g., intraocular hemorrhage). Based on the assumption that the profile of circulating miRNAs is often altered in human cancers, we verified whether UM patients showed different vitreous humor (VH) or serum miRNA profiles with respect to healthy controls. By using TaqMan Low Density Arrays, we analyzed 754 miRNAs from VH, vitreal exosomes, and serum of 6 UM patients and 6 healthy donors: our data demonstrated that the UM VH profile was unique and only partially overlapping with that from serum of the same patients. Whereas, 90% of miRNAs were shared between VH and vitreal exosomes, and their alterations in UM were statistically overlapped with those of VH and vitreal exosomes, suggesting that VH alterations could result from exosomal dysregulation. We report 32 miRNAs differentially expressed in UM patients in at least 2 different types of samples analyzed. We validated these data on an independent cohort of 12 UM patients. Most alterations were common to VH and vitreal exosomes (e.g., upregulation of miR-21,-34 a,-146a). Interestingly, miR-146a was upregulated in the serum of UM patients, as well as in serum exosomes. Upregulation of miR-21 and miR-146a was also detected in formalin-fixed, paraffin-embedded UM, suggesting that VH or serum alterations in UM could be the consequence of disregulation arising from tumoral cells. Our findings suggest the possibility to detect in VH and serum of UM patients "diagnostic" miRNAs released by the affected eye: based on this, miR-146a could be considered a potential circulating marker of UM.

Background Though several procedures of IOL implantation have been described (sutured scleral fixation, intra-scleral fixation, angle-supported anterior chamber, and anterior chamber or retropupillary iris-claw IOLs), there are no randomized trials which are comparing different techniques. Hence, the surgical treatment of aphakia still remains controversial and challenging. The purpose of this study was to compare the long-term efficacy and the rate of complications of anterior versus posterior Iris-claw intraocular lenses (IOL) implantation to correct for the treatment of aphakia without sufficient capsule support. Methods and findings Consecutive eyes having secondary implantation of aphakic iris-fixated IOLs with a follow-up of at least 5 years were considered. Mean correct distance visual acuity (CDVA) changes, percentage of eyes with CDVA improvement, mean corneal endothelial cell density (CECD) loss and the rate of other complications were used for statistical analysis. The study evaluated a total of 180 eyes (Group A: 87 anterior chamber iris-claw fixation, Group B: 93 retropupillary iris-claw implantation) of 180 consecutive different patients, with aphakia of various reasons. CDVA improved significantly in both groups after surgery (P<0.001, ANOVA), and was remarkably higher than baseline in both groups from first week and during the entire follow-up (P<0.001, Tukey’s Honest Significant Difference). There was no statistically significant difference in CDVA between the two groups during each follow-up visits (P = NS, unpaired t-test) and in the CDVA improvement percentage between the two groups (P = 0.882, Chi-square test). No significant changes in CECD were noted after surgery in both groups (ANOVA Group A: P = 0.067, Group B: P = 0.330P). No intra-operative complications occurred in both groups. There was no statistically significant difference in the rate of complications between the two groups (P = NS, Chi-square test), except for pigment precipitates which were higher in Group A (P<0.05, Chi-square test). Conclusions Five-year follow-up shows that secondary implantation of aphakic IOLs is effective and safe for the correction treatment of aphakia in eyes without capsule support.

Age related macular degeneration (AMD) is the leading cause of blindness among people aged 50 and over. Retinal deposition of amyloid-β (Aβ) aggregates in AMD patients has suggested a potential link between AMD and Alzheimer's disease (AD). We have evaluated the differential retinal expression profile of miRNAs in a rat model of AMD elicited by Aβ. A serum profile of miRNAs in AMD patients has been also assessed using single TaqMan assay. Analysis of retina from rats intravitreally injected with Aβ revealed that miR-27a, miR-146a, and miR-155 were up-regulated in comparison to control rats. Seven miRNA (miR-9, miR-23a, miR-27a, miR-34a, miR-126, miR-146a, and miR-155) have been found to be dysregulated in serum of AMD patients in comparison to control group. Analysis of pathways has revealed that dysregulated miRNAs, both in the AMD animal model and in AMD patients, can target genes regulating pathways linked to neurodegeneration and inflammation, reinforcing the hypothesis that AMD is a protein misfolding disease similar to AD. In fact, miR-9, miR-23a, miR-27a, miR-34a, miR-146a, miR-155 have been found to be dysregulated both in AMD and AD. In conclusion, we suggest that miR-9, miR-23a, miR-27a, miR-34a, miR-146a, miR-155 represent potential biomarkers and new pharmacological targets for AMD.

To analyse the postoperative foveal avascular zone (FAZ) area, superficial vessel density (SVD) and deep vessel density (DVD) and their correlation with functional (best-corrected visual acuity, BCVA) and anatomical outcomes (foveal macular thickness, FMT) after surgery for rhegmatogenous retinal detachment (RRD) repair. Method: Patients with RRD eyes, successfully treated with a single pars plana vitrectomy (PPV) with gas tamponade and a minimum 12 months follow-up, were re-examined. Foveal avascular zone (FAZ) area, SVD, DVD and FMT were evaluated by using optical coherence tomography angiography (OCTA) and compared to fellow eye. Results: Fifty-six patients with macula-on and 37 with macula-off RRD were included in the study. In both groups, no difference in FMT and FAZ area was found compared to fellow eyes. In macula-on RRD eyes, a lower parafoveal DVD (p = 0.001) was detected; FAZ area was related to FMT (p = 0.025), and the postoperative BCVA was correlated with parafoveal DVD (p = 0.010) and FAZ area (p = 0.003). In macula-off RRD eyes, lower parafoveal SDV (p = 0.012), and foveal and parafoveal DVD (p = 0.012 and p < 0.001, respectively) were observed. BCVA was related to FAZ area (p = 0.012), foveal SVD (p = 0.005) and parafoveal DVD (p = 0.010). Conclusion: Rhegmatogenous retinal detachment eyes successfully treated with PPV had lower vessel density in the superficial and deep retinal plexus compared to fellow healthy eyes; BCVA was related to FAZ area and vessel density.

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Purpose : To investigate retinal vessel density changes in macular and papillary regions in post SARS-CoV-2 pneumonia patients by means of optical coherence tomography angiography (OCTA). Design : Prospective, observational, cohort study. Methods : Forty eyes of 40 patients (mean age 49.7 ± 12.6) post SARS-CoV-2 infection and 40 healthy subjects were enrolled in this study. Covid-19 patients had to be fully recovered from Covid-19 pneumonia and were evaluated 6 months after Covid-19 infection. The primary outcome was the results of the OCTA study of the following vascular structures: vessel density (VD) in the retinal superficial capillary plexus (SCP), deep capillary plexus (DCP), radial peripapillary capillaries (RPC), compared to those of controls. We also evaluated the structural spectral domain (SD)-OCT parameters: ganglion cell complex (GCC) and retinal nerve fiber layer (RNFL). Results : The patients showed a significant reduction in VD of the SCP in whole image and in the DCP in all sectors compared to healthy subjects (p<0.05). Covid-19 patients featured a reduced VD of the RPC compared to controls (p<0.001). No difference was found in the GCC, while the RNFL was reduced in the COVID-19 group compared to controls (p=0.012). Significant correlations were found between the RNFL and VD of the SCP, DCP, RPC and FAZ area in the Covid-19 group (p<0.05). Conclusion : OCTA showed retinal vascular changes in subjects fully recovered from Covid-19 pneumonia. These findings could be a consequence of a thrombotic microangiopathy that affected retinal structures as well as other systemic organs. OCTA could represent a valid, non-invasive biomarker of early vascular dysfunction after SARS-CoV-2 infection.