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Zilliox MJ, Bouchard CS. The Microbiome, Ocular Surface, and Corneal Disorders. THE AMERICAN JOURNAL OF PATHOLOGY 2023; 193:1648-1661. [PMID: 37236506 DOI: 10.1016/j.ajpath.2023.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 04/25/2023] [Accepted: 05/09/2023] [Indexed: 05/28/2023]
Abstract
The ocular surface microbiome is an emerging field of study that seeks to understand how the community of microorganisms found on the ocular surface may help maintain homeostasis or can potentially lead to disease and dysbiosis. Initial questions include whether the organisms detected on the ocular surface inhabit that ecological niche and, if so, whether there exists a core microbiome found in most or all healthy eyes. Many questions have emerged around whether novel organisms and/or a redistribution of organisms play a role in disease pathogenesis, response to therapies, or convalescence. Although there is much enthusiasm about this topic, the ocular surface microbiome is a new field with many technical challenges. These challenges are discussed in this review as well as a need for standardization to adequately compare studies and advance the field. In addition, this review summarizes the current research on the microbiome of various ocular surface diseases and how these findings may impact treatments and clinical decision-making.
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Affiliation(s)
- Michael J Zilliox
- Department of Ophthalmology, Loyola University Medical Center, Maywood, Illinois
| | - Charles S Bouchard
- Department of Ophthalmology, Loyola University Medical Center, Maywood, Illinois.
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Mitra S, Chandran K, Fernandes M. Practical tips and common mistakes in ocular microbiology sampling and processing. Indian J Ophthalmol 2023; 71:1698-1705. [PMID: 37203021 PMCID: PMC10391500 DOI: 10.4103/ijo.ijo_2190_22] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023] Open
Abstract
Ocular microbiology deals with miniscule samples from ocular infections, which are difficult to collect, process, and analyze, necessitating special skills, and the knowledge of troubleshooting errors to reach a specific diagnosis. In this article, we highlight several practical points in ocular microbiology, common mistakes, and various approaches to resolve them. We have covered sample collection from different ocular compartments, processing for smear preparation and culture, transport of samples, staining and reagents issues, artifacts and contaminants, and interpretation of in-vitro antimicrobial susceptibility testing reports. This review aims to help both ophthalmologists and microbiologists in making the practice of ocular microbiology and the interpretation of reports more reliable, hassle-free, and precise.
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Affiliation(s)
- Sanchita Mitra
- Consultant Microbiologist, Jhaveri Microbiology Centre, LV Prasad Eye Institute, Kallam Anji Reddy Campus, Hyderabad, Telangana, India
| | - Kavya Chandran
- Consultant Ophthalmologist, Shantilal Shanghvi Cornea Institute, LV Prasad Eye Institute, Kallam Anji Reddy Campus, Hyderabad, Telangana, India
| | - Merle Fernandes
- Consultant Ophthalmologist, Shantilal Shanghvi Cornea Institute, LV Prasad Eye Institute, Kallam Anji Reddy Campus, Hyderabad, Telangana, India
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Characterising the tear bacterial microbiome in young adults. Exp Eye Res 2022; 219:109080. [DOI: 10.1016/j.exer.2022.109080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 03/25/2022] [Accepted: 04/11/2022] [Indexed: 11/22/2022]
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Delbeke H, Casteels I, Joossens M. The Effect of Topical Anesthetics on 16S Ribosomal Ribonucleic Acid Amplicon Sequencing Results in Ocular Surface Microbiome Research. Transl Vis Sci Technol 2022; 11:2. [PMID: 35238917 PMCID: PMC8899854 DOI: 10.1167/tvst.11.3.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
PURPOSE To clarify the short-term effect of topical anesthetics on 16S ribosomal ribonucleic acid amplicon sequencing results in ocular surface microbiome research. METHODS Both eyes of 24 eligible volunteers undergoing general anesthesia were sampled. Before sampling, a drop of artificial tears or a drop of topical anesthetic was applied in a randomized way. By using artificial tears as a control, we assured blinding of the executer and took a potential diluting effect into account. Bacterial DNA was extracted using the QIAGEN RNeasy PowerMicrobiome Kit with specific adaptations. Amplified DNA was sequenced with the Illumina MiSeq sequencing platform. RESULTS Four sample pairs were excluded due to low yield of bacterial DNA. In the remaining 20 sample pairs, no differences were observed with topical anesthetics at the levels of amplicon sequence variants (ASVs), phylum, genera, or alpha and beta diversity. Weighted UniFrac distance confirmed that the intraindividual distance between the right and left eye was smaller than the effect of the topical anesthetic. Interestingly, however, we identified Cutibacterium as a potential discriminative biomarker for topical anesthetic use. Overall, a significantly higher number of observed reads were assigned to genera with Gram-positive characteristics. CONCLUSIONS Based on our targeted, double-blinded, within-subject study, topical anesthetics do not affect the overall sequencing results but display a specific effect on Cutibacterium. When comparing research results, the impact of topical anesthetics on prevalence and abundance of Cutibacterium should be considered. TRANSLATIONAL RELEVANCE Understanding and standardization of sampling techniques are indispensable to properly execute clinical microbiome research.
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Affiliation(s)
- Heleen Delbeke
- Department of Ophthalmology, University Hospitals Leuven, Leuven, Belgium,KU Leuven, Biomedical Sciences Group, Department of Neurosciences, Research Group Ophthalmology, Leuven, Belgium
| | - Ingele Casteels
- Department of Ophthalmology, University Hospitals Leuven, Leuven, Belgium,KU Leuven, Biomedical Sciences Group, Department of Neurosciences, Research Group Ophthalmology, Leuven, Belgium
| | - Marie Joossens
- Department of Biochemistry and Microbiology, Ghent University, Ghent, Belgium
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Dang A, Reddy AJ, Pokala V, Rabara J, Brahmbhatt H. An Analysis of the Use of Proparacaine in Cataract Surgery. Cureus 2022; 14:e22175. [PMID: 35308736 PMCID: PMC8923310 DOI: 10.7759/cureus.22175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/13/2022] [Indexed: 11/12/2022] Open
Abstract
A cataract is the primary cause of preventable blindness and is characterized by a congenital, developmental, or acquired opacity of the human lens. Cataracts are predominantly treated through surgical procedures utilizing a combination of anesthetic agents such as proparacaine to reduce patient discomfort. Proparacaine is used to inhibit voltage-gated sodium channels on neuronal membranes to prevent signal propagation and pain signaling in the patient. Current clinical standards call for the utilization of 0.5% proparacaine when used for local anesthesia in cataract surgeries. In this review, the authors extracted the reported application site and concentrations of proparacaine in conjunction with various combination agents to accurately describe its usage in cataract surgery. It was found that most surgeons adhered to the standard concentrations of proparacaine and generally used tropicamide, an eye dilator, as a combination agent in cataract surgery. Additionally, surgeons preferred anesthetic application to the retrobulbar block. The authors find that although surgeons are following standard protocol, adjustments for lowering the standard dose of proparacaine could prove beneficial in preventing proparacaine toxicity. Furthermore, the authors find that more research can be conducted in the future examining other combination agents for use with proparacaine to improve patient outcomes.
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Pedrotti E, Bonacci E, Kilian R, Pagnacco C, Fasolo A, Anastasi M, Manzini G, Bosello F, Marchini G. The Role of Topical Povidone-Iodine in the Management of Infectious Keratitis: A Pilot Study. J Clin Med 2022; 11:jcm11030848. [PMID: 35160298 PMCID: PMC8837158 DOI: 10.3390/jcm11030848] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/29/2022] [Accepted: 02/02/2022] [Indexed: 02/04/2023] Open
Abstract
The aim of this prospective explorative study was to evaluate the safety and the effectiveness of topical polyvinylpyrrolidone-iodine (PVP-I) administered during the time-to-results period for pathogen identification and susceptibility testing in patients with infectious keratitis (IK). A corneal swab (CS) for antimicrobial evaluation was performed at enrollment (T0) and topical 0.66%-PVP-I was administered until the laboratory results were available (T1). Ulcer and infiltrate areas and infiltrate depths were compared between T0 and T1 (i.e., time-to-result period). Patients were then shifted to a specific antimicrobial therapy and followed up until resolution of their infiltrates (Tlast-TL). Twenty-five eyes were enrolled, and none showed clinical worsening leading to protocol withdrawal. At T1, ulcer and infiltrate areas showed significant improvement in Gram-positive IK (n = 13–52%; p = 0.027 and p = 0.019, respectively), remained stable in fungal IK (n = 5–20%; both p = 0.98) and increased in those with Gram-negative bacteria (n = 4–16%; p = 0.58 and p = 0.27). Eyes with negative cultures (n = 3–12%) showed complete resolution at T1 and did not initiate any additional antimicrobial therapy. The administration of 0.66% PVP-I during the time-to-result period seems to be a safe strategy in patients with IK while often sparing broad-spectrum antimicrobial agents. In addition, it showed to be effective in eyes with a Gram-positive bacterial infection.
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Affiliation(s)
- Emilio Pedrotti
- Ophthalmic Unit, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, 37129 Verona, Italy; (E.P.); (E.B.); (C.P.); (A.F.); (M.A.); (G.M.); (F.B.); (G.M.)
| | - Erika Bonacci
- Ophthalmic Unit, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, 37129 Verona, Italy; (E.P.); (E.B.); (C.P.); (A.F.); (M.A.); (G.M.); (F.B.); (G.M.)
| | - Raphael Kilian
- Ophthalmic Unit, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, 37129 Verona, Italy; (E.P.); (E.B.); (C.P.); (A.F.); (M.A.); (G.M.); (F.B.); (G.M.)
- Correspondence:
| | - Camilla Pagnacco
- Ophthalmic Unit, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, 37129 Verona, Italy; (E.P.); (E.B.); (C.P.); (A.F.); (M.A.); (G.M.); (F.B.); (G.M.)
| | - Adriano Fasolo
- Ophthalmic Unit, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, 37129 Verona, Italy; (E.P.); (E.B.); (C.P.); (A.F.); (M.A.); (G.M.); (F.B.); (G.M.)
- Research Center, The Veneto Eye Bank Foundation, 30174 Venezia, Italy
| | - Marco Anastasi
- Ophthalmic Unit, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, 37129 Verona, Italy; (E.P.); (E.B.); (C.P.); (A.F.); (M.A.); (G.M.); (F.B.); (G.M.)
| | - Gessica Manzini
- Ophthalmic Unit, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, 37129 Verona, Italy; (E.P.); (E.B.); (C.P.); (A.F.); (M.A.); (G.M.); (F.B.); (G.M.)
| | - Francesca Bosello
- Ophthalmic Unit, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, 37129 Verona, Italy; (E.P.); (E.B.); (C.P.); (A.F.); (M.A.); (G.M.); (F.B.); (G.M.)
| | - Giorgio Marchini
- Ophthalmic Unit, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, 37129 Verona, Italy; (E.P.); (E.B.); (C.P.); (A.F.); (M.A.); (G.M.); (F.B.); (G.M.)
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Reynolds MM, Mercill SL, Wirkus AL, Greenwood Quaintance K, Pulido JS. Topical proparacaine eye drops to improve the experience of patients undergoing intravitreal injections: A randomized controlled trial. Eur J Ophthalmol 2020; 30:1454-1460. [PMID: 31983237 DOI: 10.1177/1120672120902026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE We sought to evaluate whether additional topical anesthetic, specifically proparacaine 0.5%, improved patient experience with intravitreal injections without hindering antisepsis. METHODS A prospective, randomized controlled trial was conducted including 36 eyes of 36 patients undergoing intravitreal injections. Patients were randomized to treatment with additional topical proparacaine 0.5% versus control after undergoing informed consent. All patients prior to intravitreal injection underwent conjunctival culture after one drop of topical proparacaine 0.5% was placed. Half of patients then received an additional drop of proparacaine and then underwent a second conjunctival culture. The other half of patients had a drop of povidone iodine and then a second conjunctival culture. Intravitreal injection followed conjunctival cultures. To evaluate their experience, patients were provided with a survey. RESULTS In total, 36 patients were enrolled in the study. Three of 36 (8.3%) patients had positive conjunctival cultures after proparacaine eye drops alone. One of 17 (5.8%) patients had a positive conjunctival culture after a second drop of proparacaine. One of 19 (5.3%) patients had a positive culture after proparacaine and povidone iodine. By noninferiority analysis, proparacaine was inferior to povidone iodine (p = .28). Patient experience surveys did not differ between groups. CONCLUSION Patient perception did not significantly differ whether or not additional proparacaine drops were used prior to intravitreal injection in a randomized controlled trial. While proparacaine has some antiseptic properties, these were found to be inferior to those of povidone iodine. Therefore, while povidone iodine is essential for antisepsis, additional proparacaine drops should not interfere with antisepsis.
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Affiliation(s)
- Margaret M Reynolds
- Department of Ophthalmology, Washington University in St. Louis, St. Louis, MO, USA
| | - Sharon L Mercill
- Department of Nursing, Mayo Clinic and Mayo Foundation, Rochester, MN, USA
| | - Amber L Wirkus
- Department of Nursing, Mayo Clinic and Mayo Foundation, Rochester, MN, USA
| | - Kerryl Greenwood Quaintance
- Department of Laboratory Medicine, Mayo Clinic and Mayo Foundation, Rochester, MN, USA.,Department of Infectious Disease, Mayo Clinic and Mayo Foundation, Rochester, MN, USA
| | - Jose S Pulido
- Department of Ophthalmology, Mayo Clinic and Mayo Foundation, Rochester, MN, USA.,Department of Molecular Medicine, Mayo Clinic and Mayo Foundation, Rochester, MN, USA
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Banks KC, Ericsson AC, Reinero CR, Giuliano EA. Veterinary ocular microbiome: Lessons learned beyond the culture. Vet Ophthalmol 2019; 22:716-725. [PMID: 31070001 DOI: 10.1111/vop.12676] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 02/27/2019] [Accepted: 04/12/2019] [Indexed: 01/08/2023]
Abstract
Ocular pathogens cause many painful and vision-threatening diseases such as infectious keratitis, uveitis, and endophthalmitis. While virulent pathogens and pathobionts play important roles in disease pathogenesis, the scientific community has long assumed disruption of the ocular surface occurs prior to microbial colonization and subsequent infection. While nonpathogenic bacteria are often detected in corneal and conjunctival cultures from healthy eyes, cultures also frequently fail to yield growth of common ocular pathogens or nonpathogenic bacteria. This prompts the following question: Is the ocular surface populated by a stable microbial population that cannot be detected using standard culture techniques? The study of the microbiome has recently become a widespread focus in physician and veterinary medicine. Research suggests a pivotal symbiotic relationship with these microbes to maintain healthy host tissues, and when altered is associated with various disease states ("dysbiosis"). The microbiota that lives within and on mammalian bodies have long been known to influence health and susceptibility to infection. However, limitations of traditional culture methods have resulted in an incomplete understanding of what many now call the "forgotten organ," that is, the microbiome. With the introduction of high-throughput sequencing, physician ophthalmology has recognized an ocular surface with much more diverse microbial communities than suspected based on traditional culture. This article reviews the salient features of the ocular surface microbiome and highlights important future applications following the advent of molecular techniques for microbial identification, including characterizing ocular surface microbiomes in our veterinary species and their potential role in management of infectious and inflammatory ocular diseases.
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Affiliation(s)
- Kayla C Banks
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, Missouri
| | - Aaron C Ericsson
- Department of Veterinary Pathobiology, University of Missouri, Columbia, Missouri
| | - Carol R Reinero
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, Missouri
| | - Elizabeth A Giuliano
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, Missouri
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