Cannabis is the most prevalent drug in the world and its consumption is growing. Cannabinoid receptors are present in the human central nervous system. Recent studies show evidence of the effects of cannabinoids on the retina, and synthesising the results of these studies may be relevant for ophthalmologists. Thus, this review adopts standardised, systematic review methodology to investigate the effects of exposure to cannabis and components on the retina. We searched five online databases for the combined terms for outcome ("retina") and exposure ("cannabis"). Eligibility of studies were conducted by two independent reviewers, and risk of bias was assessed. We retrieved 495 studies, screened 229 studies, assessed 52 studies for eligibility, and included 16 studies for qualitative analysis. The cannabinoids most frequently investigated were delta-9-tetrahydrocannabinol (THC), abnormal cannabidiol, synthetic cannabinoid, and cannabidiol (CDB). The outcomes most studied were neuroretinal dysfunction, followed by vascular effects. The studies also included investigation of neuroprotective and anti-inflammatory effects and teratogenic effects. This review suggests that cannabinoids may have an important role in retinal processing and function.

Over the last decade, genetic studies, including genome-wide association studies (GWAS), have accelerated the discovery of genes and genomic regions contributing to primary open-angle glaucoma (POAG), a leading cause of irreversible vision loss. Here, we review the findings of genetic studies of POAG published in English prior to September 2019. In total, 74 genomic regions have been associated at a genome-wide level of significance with POAG susceptibility. Recent POAG GWAS provide not only insight into global and ethnic-specific genetic risk factors for POAG susceptibility across populations of diverse ancestry, but also important functional insights underlying biological mechanisms of glaucoma pathogenesis. In this review, we also summarize the genetic overlap between POAG, glaucoma endophenotypes, such as intraocular pressure and vertical cup-disc ratio (VCDR), and other eye disorders. We also discuss approaches recently developed to increase power for POAG locus discovery and to predict POAG risk. Finally, we discuss the recent development of POAG gene-based therapies and future strategies to treat glaucoma effectively. Understanding the genetic architecture of POAG is essential for an earlier diagnosis of this common eye disorder, predictive testing of at-risk patients, and design of gene-based targeted medical therapies none of which are currently available.

PURPOSE: To review the published literature assessing the efficacy of binocular therapy for the treatment of amblyopia compared with standard treatments. METHODS: Literature searches with no date restrictions and limited to the English language were conducted in January 2018 and updated in April 2019 in the PubMed database and the Cochrane Library database with no restrictions. The search yielded 286 citations, and the full text of 50 articles was reviewed. Twenty articles met the inclusion criteria for this assessment and were assigned a level of evidence rating by the panel methodologist. Six studies were rated level I, 1 study was rated level II, and 13 studies were rated level III because of the impact on the development and popularization of this technology. RESULTS: Two of the level I and II studies reviewed described a significant improvement in visual acuity in the binocular group versus standard patching standard treatment (the total number of patients in these 2 studies was 147). However, the 5 studies that failed to show a visual improvement from binocular therapy compared with standard treatments were larger and more rigorously designed (the total number of patients in these 5 studies was 813). Level I and II studies also failed to show a significant improvement over baseline in sensory status, including depth of suppression and stereopsis of those treated with binocular therapy. Several smaller level III case series (total number of patients in these 13 studies was 163) revealed more promising results than the binocular treatments studied in the level I and II studies, especially using treatments that are more engaging and are associated with better compliance. CONCLUSIONS: There is no level I evidence to support the use of binocular treatment as a substitute for current therapies for amblyopia (including patching and optical treatment). Furthermore, 2 large randomized controlled trials showed inferior performance compared with standard patching treatment. On the basis of this review of the published literature, binocular therapy cannot be recommended as a replacement for standard amblyopia therapy. However, more research is needed to determine the potential benefits of proposed binocular treatments in the future.

The functional competence of corneal endothelial cells (CEnCs) is critical for survival of corneal allografts, but these cells are often targets of the immune response mediated by graft-attacking effector T cells. Although regulatory T cells (Tregs) have been studied for their role in regulating the host's alloimmune response towards the graft, the cytoprotective function of these cells on CEnCs has not been investigated. The aim of this study was to determine whether Tregs suppress effector T cell-mediated and inflammatory cytokine-induced CEnC death, and to elucidate the mechanism by which this cytoprotection occurs. Using 2 well-established models of corneal transplantation (low-risk and high-risk models), we show that Tregs derived from low-risk graft recipients have a superior capacity in protecting CEnCs against effector T cell-mediated and interferon-γ and tumor necrosis factor-α-induced cell death compared to Tregs derived from high-risk hosts. We further demonstrate that the cytoprotective function of Tregs derived from low-risk hosts occurs independently of direct cell-cell contact and is mediated by the immunoregulatory cytokine IL-10. Our study is the first to report that Tregs provide cytoprotection for CEnCs through secretion of IL-10, indicating potentially novel therapeutic targets for enhancing CEnC survival following corneal transplantation.

BACKGROUND/AIMS: There is a paucity of large trials investigating the effect of management strategies for paediatric non-infectious uveitis on complications requiring surgery. The purpose of our study is to investigate whether earlier initiation of systemic immunosuppression in paediatric non-infectious uveitis is associated with fewer ophthalmic surgeries. METHODS: A retrospective review was conducted on 48 children with non-infectious uveitis assessed in 1998-2013. Patients were divided into uveitis diagnosed before December 2008 (group 1) and after January 2009 (group 2). Duration from uveitis onset to methotrexate initiation (U-MTX) and biological addition (U-Biologic) were reviewed. Follow-up visits with topical corticosteroids >3 times daily and active uveitis (≥1+ cells) during 3.5 years were documented. The main outcome measure was the need for ≥1 ophthalmic surgery at 3.5 years. RESULTS: In group 1, 69.5% of patients required ≥1 ophthalmic surgery at 3.5 years versus 26.9% in group 2 (p=0.005). U-MTX was 28.9±11.8 weeks and 14.2±10.0 weeks for groups 1 and 2 (p=0.028). U-Biologic was 134.6±46.0 weeks and 82.3±43.3 weeks for groups 1 and 2 (p=0.0016). Corticosteroid use >3 times daily was 85.9±52.7 weeks and 14.6±11.1 weeks for groups 1 and 2. Multivariate regression showed methotrexate initiation within 6 months of uveitis onset lowered the likelihood of needing ophthalmic surgery at 3.5 years (OR=6.2, 95% CI 1.2 to 33.4; p=0.033). Univariate regression demonstrated biological addition within 18 months of uveitis onset reduced the likelihood of requiring ophthalmic surgery (OR 12.57, 95% CI 1.28 to 123.48; p=0.030). CONCLUSION: Earlier control of uveitis by addition of immunosuppressive therapy reduced the need for ophthalmic surgery.

PURPOSE: To investigate whether anti-vascular endothelial growth factor (anti-VEGF) for diabetic macular edema or proliferative diabetic retinopathy (PDR) increases the risk of traction retinal detachment (TRD) among eyes with PDR. METHODS: Pooled analysis of PDR eyes from Protocols I, J, N, S, or T with Early Treatment Diabetic Retinopathy Study level ≥61 (prompt vitrectomy was not planned) randomly assigned to the control group (laser photocoagulation, sham, or intravitreal saline; 396 eyes) or anti-VEGF (487 eyes). The primary outcome was investigator-identified TRD within 1 year of randomization. RESULTS: The 1-year cumulative probability of TRD was 6.8% (95% confidence interval: 4.6%-9.9%, 25 events) in control-group eyes and 4.8% (95% confidence interval: 3.2%-7.3%, 22 events) in anti-VEGF group eyes (hazard ratio = 0.95 [95% confidence interval: 0.54-1.66, P = 0.86]). The cumulative probability of vitrectomy for TRD was 4.4% (16 events) in control-group eyes and 2.2% (9 events) in anti-VEGF group eyes (P = 0.19). Percentage with TRD and vitrectomy for TRD were similar within strata of diabetic retinopathy severity. CONCLUSION: These findings do not support the hypothesis that anti-VEGF therapy for diabetic macular edema or PDR increases the risk of TRD among eyes with PDR similar to those enrolled in five DRCR Retina Network protocols for which prompt vitrectomy was not planned.

Deep learning (DL) is a subset of artificial intelligence (AI), which uses multilayer neural networks modelled after the mammalian visual cortex capable of synthesizing images in ways that will transform the field of glaucoma. Autonomous DL algorithms are capable of maximizing information embedded in digital fundus photographs and ocular coherence tomographs to outperform ophthalmologists in disease detection. Other unsupervised algorithms such as principal component analysis (axis learning) and archetypal analysis (corner learning) facilitate visual field interpretation and show great promise to detect functional glaucoma progression and differentiate it from non-glaucomatous changes when compared with conventional software packages. Forecasting tools such as the Kalman filter may revolutionize glaucoma management by accounting for a host of factors to set target intraocular pressure goals that preserve vision. Activation maps generated from DL algorithms that process glaucoma data have the potential to efficiently direct our attention to critical data elements embedded in high throughput data and enhance our understanding of the glaucomatous process. It is hoped that AI will realize more accurate assessment of the copious data encountered in glaucoma management, improving our understanding of the disease, preserving vision, and serving to enhance the deep bonds that patients develop with their treating physicians.