Role of intestinal microbiome in the pathogenesis of age-related macular degeneration

Background: The microbiome is strongly linked to many extra-intestinal disorders. Gut commensal microbiota, in particular, plays an active role in human immune and intestinal homeostasis. Complex interactions of the microbiota with host genetics and other underlying factors lead to intestinal dysbiosis, which is thought to be linked to ocular inflammatory diseases. Thus, the aim of this review is to analyze the role of intestinal microbiome in age-related macular degeneration (AMD). Methods: A thorough literature search was performed using PubMed/MEDLINE, limited to English language publications, from January 2004 to March 2020. An additional search was made employing Google Scholar to complete the collected data as per the above-mentioned time-line and language limitations. The main keywords used included age-related macular degeneration, microbiome, dysbiosis, autoimmunity, gut microbiota, epigenetics, immune-mediated inflammatory diseases, and gut-retina axis. Results: Recent studies have proposed the role of intestinal microbiota in the pathogenesis of AMD. Changes in the microbiome have been shown to trigger several ocular inflammatory processes. There is increasing evidence demonstrating that intestinal microbial imbalance may play an important role in the pathogenesis of AMD. Conclusions: This review summarizes how alterations in the intestinal microbiota can be associated with the pathogenesis of AMD and how new therapeutic modalities can be designed to target this microbiome to limit the severe nature of this disease. Future advances in microbiome research may unveil a new era in understanding and managing AMD

Diagnostic and therapeutic approaches to optic disc pit maculopathy in children

Background: Optic disc pit (ODP) is a rare congenital defect of the optic disc that can lead to maculopathy and gradual visual impairment. This review summarizes our current knowledge on the diagnostic and therapeutic approaches to ODP maculopathy (ODP-M) in children. Methods: A thorough literature search was performed using the PubMed/MEDLINE database from 1960 to 2020. An additional search was conducted using Google Scholar for completeness. Results: ODP-M is characterized by the accumulation of subretinal and/or intraretinal fluid. The exact pathogenetic mechanisms are not fully understood, and the origin of the fluid remains unknown. Although ODP-M is more likely to occur during the third or fourth decade of life, cases of children with serous retinal detachment have been recorded. Early diagnosis of ODP-M and prompt, appropriate management are crucial, particularly in patients of amblyogenic age. In adults, ODP-M may resolve spontaneously, but most cases require surgical intervention to prevent permanent loss of vision. However, the fact that ODP-M may spontaneously resolve in children cannot be ignored. Various surgical methods have been described, including pars plana vitrectomy (PPV) combined with various techniques, including laser photocoagulation, intravitreal gas injection, and macular buckling. Conclusions: PPV remains the mainstay surgical approach for ODP-M. However, ODP-M may differ between children and adults. Children constitute a unique population of patients that require a different and probably more tailor-made approach. Detailed clinical examination, combined with a thorough analysis of retinal imaging, may improve our understanding of the background and pathophysiology of the disease and eventually provide us with new insights into the management of ODP-M in the pediatric population. How to cite this article: Kalogeropoulos D, Asproudis I,  Ch’ng SW, Mitra A, Sharma A, Katsikatsos K, Asproudis C, Kalogeropoulos C. Diagnostic and therapeutic approaches to optic disc pit maculopathy in children. Med Hypothesis Discov Innov Optom.2021 Spring; 2(1): 24-35. DOI: https://doi.org/10.51329/mehdioptometry12

Visual outcomes after management of bilateral cataract and retinal detachment in atopic dermatitis

Background: Atopic dermatitis (AD) is a chronic pruritic inflammatory skin disorder of childhood with a broad spectrum of ocular manifestations, including keratoconjunctivitis, keratoconus, cataract, and rhegmatogenous retinal detachment (RRD). This study was aimed at reporting the visual outcomes in patients with bilateral cataract and RRD in the context of AD. Methods: This was a retrospective, observational case series. A thorough history, clinical features, and surgical management of seven consecutive patients who presented to the Birmingham and Midland Eye Centre with bilateral cataract and RRD secondary to severe AD were investigated. Results: Fourteen eyes of seven patients with AD were analyzed. Twelve of the 14 eyes had cataract (85.7%). Seven patients had anterior or posterior subcapsular cataract (58.3%); 13 of the 14 eyes had RRD (92.8%). Most cases were bilateral or simultaneous (85.7% and 71.4%, respectively). Eight eyes had involvement of the temporal quadrant (61.5%): three eyes had giant retinal tears (23%) and five eyes with proliferative vitreoretinopathy (38.5%). Three eyes underwent scleral buckle surgery with or without cryotherapy (21.4%), and eight eyes had PPV (57.1%) combined with other procedures. Two eyes (15.4%) had persistent RRD postoperatively. The latest recorded postoperative best-corrected distance visual acuity was 6/36 or better in 10 (71.4%) eyes. Conclusions: Temporal RRD was commonly observed in retinal detachment secondary to AD. Surgical repair was often challenging because of proliferative vitreoretinopathy and significant cataract. A further multidisciplinary study involving dermatologists would be helpful in identifying a larger high-risk population for AD and earlier detection of asymptomatic retinal tears or holes, which would allow preventive treatment and limit sight-threatening complications

Trace Metals Distribution in Tissues of 10 Different Shark Species from the Eastern Mediterranean Sea

As long-living apex predators, sharks tend to bioaccumulate trace metals through their diet. The distribution of Al, As, Cd, Co, Cr, Cs, Cu, Fe, Mn, Ni, Pb, V, Zn and Hg in different tissues (muscle, liver, heart, gills and gonads) of large-size (58–390 cm) sharks, some of which rare, of the eastern Mediterranean Sea was studied. Trace metals analyses in samples originating from ten different Chondrichthyes species were performed by inductively coupled plasma–mass spectrometry (ICP-MS) and Cold Vapor Atomic Absorption Spectrometry (CVAAS) for Hg. Data on trace metal levels are for the first time reported herewith for the species O. ferox and H. nakamurai. Higher median concentrations of trace metals were generally determined in the liver. The concentrations of Hg, Cs and As in the muscle increased proportionally with body length. Statistically significant differences between sexes were recorded for Hg, Cr, Ni and As (p = 0.015) in the muscle tissues of P. glauca. Muscle tissue Hg concentrations exceeded the EU maximum limit (1 μg g−1 wet weight) in 67% of the individuals sampled, with the highest concentrations detected in O. ferox and S. zygaena, whereas regarding Pb (limit 0.30 μg g−1 ww), the corresponding percentage was 15%. Arsenic concentrations were also of concern in almost all shark tissues examined