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Zantut PRA, Veras MM, Yariwake VY, Takahashi WY, Saldiva PH, Young LH, Damico FM, Fajersztajn L. Effects of cannabis and its components on the retina: a systematic review. Cutan Ocul Toxicol 2020;39(1):1-9.Abstract
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.
Choquet H, Wiggs JL, Khawaja AP. Clinical implications of recent advances in primary open-angle glaucoma genetics. Eye (Lond) 2020;34(1):29-39.Abstract
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.
Cheung CSY, Mireskandari K, Ali A, Silverman E, Tehrani N. Earlier use of systemic immunosuppression is associated with fewer ophthalmic surgeries in paediatric non-infectious uveitis. Br J Ophthalmol 2020;104(7):938-942.Abstract
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.
Porporato N, Baskaran M, Tun TA, Sultana R, Tan M, Quah JHM, Allen JC, Perera S, Friedman DS, Cheng CY, Aung T. Understanding diagnostic disagreement in angle closure assessment between anterior segment optical coherence tomography and gonioscopy. Br J Ophthalmol 2020;104(6):795-799.Abstract
BACKGROUND/AIMS: Although being a more objective tool for assessment and follow-up of angle closure, reliability studies have reported a moderate diagnostic performance for anterior segment optical coherence tomography (OCT) technologies when comparing with gonioscopy as the reference standard. We aim to determine factors associated with diagnostic disagreement in angle closure when assessed by anterior segment swept source OCT (SS-OCT, CASIA SS-1000; Tomey, Nagoya, Japan) and gonioscopy. METHODS: Cross-sectional study. A total of 2027 phakic subjects aged ≥50 years, with no relevant previous ophthalmic history, were consecutively recruited from a community polyclinic in Singapore. Gonioscopy and SS-OCT (128 radial scans) for the entire circumference of the angle were performed for each subject. A two-quadrant closed gonioscopic definition was used. On SS-OCT images, angle closure was defined as iridotrabecular contact (ITC) to the extent of ≥35%, ≥50% and ≥75% of the circumferential angle. Diagnostic disagreements between both methods, that is, false positives or overcalls and false negatives or undercalls were defined, respectively, as gonioscopic open/closed angles inversely assessed as closed/open by SS-OCT. RESULTS: Two hundred and seventy-two (14.7%) resulted in overcall results (false positives) when ≥50% of the angle circumference was closed using SS-OCT. These eyes had significantly wider (anterior chamber width, 11.7 vs 11.6 mm, p<0.001) and deeper (anterior chamber depth (ACD), 2.4 vs 2.2 mm, p<0.001) anterior chambers than eyes assessed by both methods as closed (true positives). Deeper ACD (OR 9.31) and lower lens vault (LV) (OR 0.04) were significantly associated with a false positive diagnosis in the multivariate analysis. Most of these cases had short (52.6%) or irregular (39%) ITC in SS-OCT images. CONCLUSIONS: We found that anterior chamber dimensions, determined by ACD and LV, were factors significantly associated with diagnostic disagreement between anterior segment SS-OCT and gonioscopy in angle closure assessment.
Mayro EL, Wang M, Elze T, Pasquale LR. The impact of artificial intelligence in the diagnosis and management of glaucoma. Eye (Lond) 2020;34(1):1-11.Abstract
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.
Wang J, Chen D, Sullivan DA, Xie H, Li Y, Liu Y. Expression of Lubricin in the Human Amniotic Membrane. Cornea 2020;39(1):118-121.Abstract
PURPOSE: Lubricin, a boundary lubricant, is the body's unique antiadhesive, antifibrotic, antifriction, and antiinflammatory glycoprotein. This amphiphile is produced by numerous tissues and acts to regulate a number of processes, such as homeostasis, shear stress, tissue development, innate immunity, inflammation, and wound healing. We hypothesize that lubricin is also synthesized and expressed by the amniotic membrane (AM), which also possesses antiadhesive, antifibrotic, and antiinflammatory properties. We also hypothesize that lubricin, at least in part, mediates these AM capabilities. Our goal was to test our hypothesis. METHODS: We obtained multiple samples of fresh, cryopreserved (CP), and freeze-dried (FD) human AMs, as well as fresh placental tissue as positive controls, and processed them for light microscopy, immunofluorescence, and western blot analyses. We also evaluated the ability of recombinant human lubricin to associate with FD-AMs. RESULTS: Our results demonstrate that all fresh placental, fresh AM, and CP-AM samples contained lubricin. Lubricin was expressed in placental chorionic villi, AM epithelial and stromal cells, and CP-AM epithelia. No lubricin could be detected in FD-AMs but could be restored in FD-AMs after overnight incubation with recombinant human lubricin. CONCLUSIONS: This study supports our hypothesis that lubricin is expressed in human AMs. In addition, our data show that preservation methods influence the extent of this expression. Indeed, the disappearance of lubricin in FD-AMs may explain why dried AM reportedly loses its antiinflammatory and antiscarring abilities. It is possible that lubricin may mediate, at least in part, many of the biological properties of AMs.
Xiao J, Adil MY, Chen X, Utheim ØA, Ræder S, Tønseth KA, Lagali NS, Dartt DA, Utheim TP. Functional and Morphological Evaluation of Meibomian Glands in the Assessment of Meibomian Gland Dysfunction Subtype and Severity. Am J Ophthalmol 2020;209:160-167.Abstract
PURPOSE: To classify subtypes of meibomian gland dysfunction (MGD) and evaluate the dependency of dry eye signs, symptoms, and parameters on MGD subtype. DESIGN: Cross-sectional study. STUDY POPULATION: the right eyes of 447 patients with MGD of various subtypes and 20 healthy volunteers. METHODS: Patients were divided into 4 subtypes of MGD based on meibum expression, meibum quality, and MG loss on meibography images (meibograde of 0-6). Subtypes were patients with high meibum delivery (hypersecretory and nonobvious MGD) and those with low meibum delivery (hyposecretory and obstructive MGD). Additional clinical tests included tear film break-up time (TFBUT), ocular staining, osmolarity, Schirmer I, blink interval timing and the Ocular Surface Disease Index (OSDI) questionnaire. RESULTS: A total of 78 eyes had hypersecretory MGD; 49 eyes had nonobvious MGD; 66 eyes had hyposecretory MGD; and 254 eyes had obstructive MGD. Increased tear film osmolarity and lower TFBUT were found in the low-delivery groups; hyposecretory (P = 0.006, P = 0.016) and obstructive MGD (P = 0.008, P = 0.006) relative to high-delivery MGD (hypersecretory and nonobvious groups, respectively). Worse ocular symptoms and ocular staining were also found in low-delivery MGD groups than the high delivery MGD groups (P < 0.01 and P < 0.006, respectively). CONCLUSIONS: Patients with low-delivery MGD had worse dry eye parameters and ocular symptoms than those with high meibum delivery, indicating the pivotal role of meibum secretion in ocular surface health that should be targeted in MGD therapy. Furthermore, nonobvious MGD cannot be diagnosed using conventional dry eye tests and requires morphologic assessment of meibography images to confirm MG loss.
Bressler NM, Beaulieu WT, Bressler SB, Glassman AR, Melia MB, Jampol LM, Jhaveri CD, Salehi-Had H, Velez G, Sun JK, Sun JK. ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR THERAPY AND RISK OF TRACTION RETINAL DETACHMENT IN EYES WITH PROLIFERATIVE DIABETIC RETINOPATHY: Pooled Analysis of Five DRCR Retina Network Randomized Clinical Trials. Retina 2020;40(6):1021-1028.Abstract
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.
Sakurada Y, Fragiotta S, Leong BCS, Parikh R, Hussnain AS, Freund BK. RELATIONSHIP BETWEEN CHOROIDAL VASCULAR HYPERPERMEABILITY, CHORIOCAPILLARIS FLOW DENSITY, AND CHOROIDAL THICKNESS IN EYES WITH PACHYCHOROID PIGMENT EPITHELIOPATHY. Retina 2020;40(4):657-662.Abstract
PURPOSE: To use swept-source optical coherence tomography and swept-source optical coherence tomography angiography to investigate potential relationships between choroidal vascular hyperpermeability (CVH) seen with indocyanine green angiography (ICGA), choriocapillaris flow density, and choroidal thickness in eyes with pachychoroid pigment epitheliopathy. METHODS: Patients with pachychoroid pigment epitheliopathy were prospectively imaged with 12-mm × 12-mm swept-source optical coherence tomography, 12-mm × 12-mm swept-source optical coherence tomography angiographyA, and ICGA. Binarized choriocapillaris OCTA images were superimposed with ICGA images in which CVH area had been isolated. Choriocapillaris flow density within or outside the quadrants of CVH was calculated and the ratio of these two values was determined. The presence of CVH and choroidal thickness was evaluated at 9 locations within a central 3-mm × 3-mm area to explore the relationship between these 2 factors. RESULTS: Ten eyes from 10 patients were enrolled in the present study. Choriocapillaris flow density within quadrants of CVH area was significantly lower compared with quadrants without CVH (P < 0.001). The mean choriocapillaris flow density ratio was 0.86 ± 0.10 (range: 0.65-0.99). From among the 90 locations in 10 study eyes, 48 were within areas of CVH. Choroidal thickness was greater in quadrants of CVH compared with areas without CVH (P < 0.001, 455 ± 122 µm vs. 297 ± 93 µm). CONCLUSION: Reduced choriocapillaris flow density, increased choroidal thickness, and CVH appear to co-localize in eyes with pachychoroid pigment epitheliopathy.
Tolesa K, Abateneh A, Kempen JH, Gelaw Y. Patterns of Uveitis among Patients Attending Jimma University Department of Ophthalmology, Jimma, Ethiopia. Ocul Immunol Inflamm 2020;28(7):1109-1115.Abstract
: Uveitis is an important cause of blindness and ocular morbidity in the world. The patterns of uveitis have not been well characterized in sub-Saharan Africa. : To describe the characteristics of uveitis among patients presenting to Jimma University Department of Ophthalmology (JUDO) from July 2013 to December 2014. : This hospital-based prospective cross-sectional study included all new uveitis patients visiting JUDO outpatient department during the study period. : Among 98 patients diagnosed with uveitis, anterior uveitis was found in 74.5% of patients. Majority of the patients, 83.7%, had unilateral uveitis. A uveitis syndrome was identified in 22.5% of cases; of these 15 (68.2%) were infectious. Herpes simplex uveitis was the commonest infectious cause (53.3%) while Toxoplasmosis was the most common cause of posterior uveitis (60%). : Anterior uveitis was the most common pattern found among uveitis patients. Herpes simplex and toxoplasmic chorioretinitis were the most common-identified infectious causes.
Argüeso P. Disrupted Glycocalyx as a Source of Ocular Surface Biomarkers. Eye Contact Lens 2020;46 Suppl 2:S53-S56.Abstract
The glycocalyx is a dense and diverse coat of glycans and glycoconjugates responsible for maintaining cell surface integrity and regulating the interaction of cells with the external environment. Transmembrane mucins such as MUC1 and MUC16 comprise a major component of the epithelial glycocalyx and are currently used to monitor disease progression in cancer. At the ocular surface, multiple lines of evidence indicate that abnormal expression of the enzymes responsible for glycan biosynthesis during pathological conditions impairs the glycosylation of transmembrane mucins. It is now becoming clear that these changes contribute to modify the interaction of mucins with galectin-3, a multimeric lectin crucial for preserving the ocular surface epithelial barrier. This review highlights the potential of using the epithelial glycocalyx as a reliable source for the generation of biomarkers to diagnose and monitor ocular surface disease.
Rao P, Lertjirachai I, Yonekawa Y, Hasbrook M, Thomas BJ, Wood EH, Mehta N, Mane G, Drenser KA, Trese MT, Capone A. ETIOLOGY AND CLINICAL CHARACTERISTICS OF MACULAR EDEMA IN PATIENTS WITH FAMILIAL EXUDATIVE VITREORETINOPATHY. Retina 2020;40(7):1367-1373.Abstract
PURPOSE: To describe the etiology and clinical characteristics of macular edema (ME) in patients with familial exudative vitreoretinopathy. METHODS: Observational, retrospective case series of 30 patients (34 eyes) with ME and familial exudative vitreoretinopathy who underwent spectral-domain optical coherence tomography imaging between 2009 and 2016. Baseline and follow-up optical coherence tomographies were correlated with color fundus photography and fluorescein angiography. RESULTS: The average age was 20.6 years (6.6-68.7). Eighteen eyes exhibited cystoid ME (52.9%), 14 noncystoid ME (41.2%), and 2 eyes (5.9%) with both. Macular edema was foveal in 52.9% (n = 18). Eighteen of 24 eyes (64.3%) with an available fluorescein angiography showed leakage from ME. The most common structural feature was posterior hyaloidal organization/contraction (n = 15). Sixteen eyes were treated with topical or intravitreal steroids (n = 6), intravitreal anti-vascular endothelial growth factor (n = 3), or pars plana vitrectomy with membrane stripping (n = 7). There was no difference between mean preoperative and postoperative LogMAR visual acuity (0.63 [20/85] vs. 0.87 [20/148], P = 0.35) after vitrectomy despite a statistical improvement in the mean central foveal thickness (596 mm vs. 303 mm, P = 0.04). CONCLUSION: Macular edema in familial exudative vitreoretinopathy occurs most commonly because of traction. Vitrectomy is effective for relieving tractional forces with anatomical improvement.
Lally DR, Kasetty MA. CLOSURE OF SMALL MACULAR HOLES USING VITRECTOMY SURGERY WITH INTERNAL LIMITING MEMBRANE PEELING WITHOUT THE USE OF INTRAOCULAR GAS TAMPONADE: BROADENING THE UNDERSTANDING OF THE MACULAR HOLE PATHOPHYSIOLOGY. Retin Cases Brief Rep 2020;14(2):104-109.Abstract
PURPOSE: To determine whether small macular hole closure can be achieved with 25-G vitrectomy surgery with internal limiting membrane peeling without the use of intraocular gas tamponade or facedown positioning. METHODS: 25-G vitrectomy surgery with internal limiting membrane peeling without the use of intraocular gas tamponade or positioning was performed on 20 eyes with a small (<400-µm diameter), full-thickness macular hole. RESULTS: In 17 of 20 eyes (85%), the hole had closed. Three holes had closed by Postoperative Day 1, 13 holes by Postoperative Week 1, 16 holes by Postoperative Week 2, and 17 holes by Postoperative Week 6. At Postoperative Month 1, vision improved in 16 of 17 eyes in which the macular hole had closed. One hole that had not closed at the first postoperative week and two holes that had not closed at the third postoperative week required follow-up surgery with intraocular gas tamponade and facedown positioning, after which the hole closed. The mean preoperative visual acuity was 0.626 logMAR (20/85), and the mean postoperative visual acuity after 1 month was 0.392 logMAR (20/50) (P < 0.001). CONCLUSION: Vitrectomy surgery with internal limiting membrane peeling without the use of gas tamponade or positioning can achieve closure of small macular holes.

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