Corneal Response to Scleral Contact Lens Wear in Keratoconus.

OBJECTIVE: To verify corneal alterations in patients with keratoconus who wear scleral contact lenses (ScCLs), focusing on corneal endothelial assessment. METHODS: Scleral contact lenses were fitted in 22 patients with keratoconus. During a 90-day follow-up, patients were assessed in three visits: at baseline, after 30 days, and after 90 days. Patients underwent visual acuity measurement, slitlamp biomicroscopy of the anterior segment, specular microscopy of the corneal endothelium, corneal pachymetry, measurement of the clearance between the cornea and the lens, and follow-up of ectasia. RESULTS: Variables related to endothelial morphology and pachymetry values did not change significantly over time. Central clearance measurements decreased in the 90-day period. No progression of corneal ectasia was observed, neither were infectious or inflammatory processes in the same period. CONCLUSION: Daily wear of ScCLs in patients with keratoconus was not associated with adverse effects on the cornea or endothelium over a period of 90 days nor was there evidence of disease progression. Central clearance values diminished over that period, but the significance of this observation remains unclear.

Production, chemical composition, and economic viability of Minas Frescal cheese from buffaloes supplemented with açai seed.

We aimed to evaluate the chemical composition, production yield, and economic viability of Minas Frescal cheese produced with milk from buffaloes supplemented with açai seed as a substitute for corn meal. The experiment used five Murrah crossbred buffaloes with a mean body weight of 577 ± 20.4 kg, maintained under Megathyrsus maximus cv. Mombaça grazing in a 5 × 5 Latin square design. The treatments comprised four concentrate supplements, in which açai seed replaced corn meal at 0, 33, 66, and 100% substitution, and a control with no concentrate supplementation. Replacement of corn meal with açai seed in buffalo diet had no effect on chemical composition of produced cheese (P > 0.05) nor was there any difference in chemical composition between the control group and animals supplemented with concentrate (P > 0.05). The adjusted cheese yield (kg cheese/cow/day) demonstrated a quadratic pattern with maximum production at 33% açai seed substitution (P < 0.05). Hence, the profitability index (percentage of gross revenue) was greatest at this replacement level. In conclusion, 33% açai seed replacement of corn meal in the supplement of buffalo under a grazing regime improved the individual yield of Minas Frescal cheese without changing its chemical composition.

Sensitivity of Enzymatic Toxins from Corneal Isolate of Acanthamoeba Protozoan to Physicochemical Parameters.

Acanthamoeba is a free-living amoeba that causes severe corneal infection (Acanthamoeba keratitis) and produces a variety of extracellular enzymes, called exoproteome. Since physicochemical characters are suggested being associated with therapeutic profile and clinical severity of the infection, we investigated the physicochemical properties of proteolysis mediated by amoebic exoproteome. Corneal scraping was collected from a patient who showed typical symptoms of acute Acanthamoeba keratitis. Axenic amoeba was phylogenetically identified by 18S rDNA sequencing analysis. Effects of pH, temperature and diamidines on proteolysis mediated by exoproteome were assessed using zymography assays. Proteolytic enzymes were most active at pH 7.0 and 37 °C. Calcium ions decreased enzymatic activity. The main components of amoebic exoproteome were characterized as serine proteases. We demonstrated for the first time that commercial antimicrobial diamidines used for Acanthamoeba keratitis therapy inhibit enzymatic activity of amoebic exoproteome. Results showed the thermostability of Acanthamoeba proteases, which suggest a long-term effect of these virulence factors at the central and peripheral cornea with possible role in degradation of extracellular matrix components. Our findings open new perspectives about the complementary and unreported properties of antimicrobial compounds of the diamidine class on the inhibition of enzymatic activity and presumptive control of amoebic infection in the cornea.

Ocular toxicity assessment of chronic sildenafil therapy for pulmonary arterial hypertension.

PURPOSE: The aim of this study was to investigate possible functional and structural ocular changes caused by chronic sildenafil therapy to treat pulmonary arterial hypertension (PAH). METHODS: Case-control study included patients with pulmonary arterial hypertension: chronically using sildenafil and without sildenafil treatment. A comprehensive ophthalmologic exam including ectoscopy, extrinsic ocular motility, logMAR visual acuity measurement, contrast sensitivity test, color test, anterior segment biomicroscopy, Schirmer test 1, intraocular pressure, fundus exam under pupil dilation, fundus pictures, time domain and spectral domain optical coherence tomography, ocular Doppler ultrasound were performed. Full-field electroretinography (ERG) was tested for each eye in a subgroup of sildenafil-treated patients. RESULTS: Twenty patients from each group were tested. Bilateral severe keratitis was found in seven (35 %) patients under sildenafil therapy. Lacrimal film break-up time (BUT) was significantly reduced (p = 0.006 respectively) and Doppler ultrasound showed a reduced resistance index of the central retinal artery in the group of sildenafil users (p = 0.019). No diffuse retinal functional abnormalities were found in ERG in treated patients. Visual acuity, contrast sensitivity and color discrimination were normal in both groups. No abnormalities were found in both time-domain and spectral-domain OCT for retinal parameters. CONCLUSIONS: One-third of the treated PAH group showed severe bilateral keratitis. This finding could be related to connective tissue abnormalities usually present in patients with this condition that might be exacerbated with the sildenafil usage. The resistance index of the central retinal artery was diminished in the chronic users group and it could be associated to the vasodilation caused by the medication in the choroidal vessels. An ophthalmic assessment for these patients is recommended to diagnose and treat possible ocular surface and choroidal blood flow abnormalities caused by sildenafil.

Mycobacterium saopaulense sp. nov., a rapidly growing mycobacterium closely related to members of the Mycobacterium chelonae--Mycobacterium abscessus group.

Five isolates of non-pigmented, rapidly growing mycobacteria were isolated from three patients and,in an earlier study, from zebrafish. Phenotypic and molecular tests confirmed that these isolates belong to the Mycobacterium chelonae-Mycobacterium abscessus group, but they could not be confidently assigned to any known species of this group. Phenotypic analysis and biochemical tests were not helpful for distinguishing these isolates from other members of the M. chelonae­M.abscessus group. The isolates presented higher drug resistance in comparison with other members of the group, showing susceptibility only to clarithromycin. The five isolates showed a unique PCR restriction analysis pattern of the hsp65 gene, 100 % similarity in 16S rRNA gene and hsp65 sequences and 1-2 nt differences in rpoB and internal transcribed spacer (ITS) sequences.Phylogenetic analysis of a concatenated dataset including 16S rRNA gene, hsp65, and rpoB sequences from type strains of more closely related species placed the five isolates together, as a distinct lineage from previously described species, suggesting a sister relationship to a group consisting of M. chelonae, Mycobacterium salmoniphilum, Mycobacterium franklinii and Mycobacterium immunogenum. DNA­DNA hybridization values .70 % confirmed that the five isolates belong to the same species, while values ,70 % between one of the isolates and the type strains of M. chelonae and M. abscessus confirmed that the isolates belong to a distinct species. The polyphasic characterization of these isolates, supported by DNA­DNA hybridization results,demonstrated that they share characteristics with M. chelonae­M. abscessus members, butconstitute a different species, for which the name Mycobacterium saopaulense sp. nov. is proposed. The type strain is EPM10906T (5CCUG 66554T5LMG 28586T5INCQS 0733T).

Cytotoxic activity and degradation patterns of structural proteins by corneal isolates of Acanthamoeba spp.

BACKGROUND: Proteolytic enzymes secreted by trophozoites (amoebic secretome) are suggested as the main virulence factor involved in the severity of Acanthamoeba keratitis. The degradation profile of the main glycoprotein components of anterior and posterior portions of the cornea and the cytopathic effect of secretomes on endothelial cells by contact-independent mechanism were evaluated. METHODS: Trophozoites were isolated primarily from corneal tissue samples (n = 11) and extracellular proteins were collected from axenic cell culture supernatants. The molecular weights of proteolytic enzymes were estimated by zymography. Enzymatic cleavage of laminin and fibronectin substrates by amoebic secretome was investigated and cluster analysis was applied to the proteolysis profiles. Primary cultures of endothelial cells were used in both qualitative and quantitative assays of cytophatogenicity. RESULTS: Differential patterns of proteolysis were observed among the Acanthamoeba secretomes that were analysed. The uniformity of laminin degradation contrasted with the diversity of the proteolysis profiles observed in the fibronectin substrate. Acanthamoeba secretome extracted from four clinical isolates was shown to be toxic when in contact with the endothelial cell monolayer (p < 0.01). Induction of apoptosis and membrane permeability, at different percentual values, were suggested as the main mechanisms that could induce endothelial cell death when in contact with amoebic secretome. CONCLUSIONS: Our results provide evidence that virulence factors secreted by Acanthamoeba trophozoites can be related to an increased pathogenicity pattern by an independent contact-trophozoite mechanism, through induction of endothelial cell death by apoptosis at a higher percentage than providing the lack of cell viability by the membrane-associated pore-forming toxin activity.

Altered hyaluronic acid content in tear fluid of patients with adenoviral conjunctivitis.

The adenoviral conjunctivitis is one of the biggest causes of conjunctival infection in the world. Conjunctivitis causes relatively nonspecific symptoms, as hyperaemia and chemosis. Even after biomicroscopy, complex laboratory tests, such as viral culture, are necessary to identify the pathogen or its etiology. To contribute to the better understanding of the pathobiology of the adenoviral conjunctivitis, the tear fluids of patients with unilateral acute adenovirus conjunctivitis (UAAC), normal donors (control) and patients with allergic conjunctivitis were analyzed. Tear samples were collected with Schirmer strips from control, allergic conjunctivitis and UAAC patients, diagnosed by clinical signs. UAAC tears were tested positive in viral cultures. After the elution, HA was quantified using an ELISA-like fluorometric assay and the protein profile was determined by SDS-PAGE. A profound increase in the HA tear content in UAAC patients was found when compared to control and ALC. This HA increase in UAAC tears remarkably was not observed in tears from contralateral eyes without clinical signs, nor in allergic conjunctivitis. In addition a distinct profile of UAAC tear proteins was observed in patients with UAAC. The quantification of HA in the tear fluid is a rapid, sensitive and specific test. This molecule might be a biomarker candidate for acute conjunctivitis.

Biologic therapy for refractory scleritis: a new treatment perspective.

Scleritis is an umbrella term for a heterogeneous group of ocular diseases that can be associated with autoimmune or systemic disorders. The purpose of this article was to review the literature regarding the use of biologic drugs to treat refractory scleritis. A search of the MEDLINE, Embase, and LILACS electronic databases was conducted, and the reference lists of published articles were hand-searched. No language filters were used. This search strategy yielded no randomized trials of the use of biologic therapies to treat scleritis; only case reports and retrospective studies were retrieved. These studies suggest that monoclonal antibodies (infliximab and adalimumab) are superior to the soluble TNF receptor fusion protein etanercept for the treatment of scleritis in patients that do not respond to corticosteroids and/or to immunosuppressive treatment. Rituximab seems to be the best option for scleritis associated with vasculitis.

Multilocus sequence typing scheme versus pulsed-field gel electrophoresis for typing Mycobacterium abscessus isolates.

Outbreaks of infections by rapidly growing mycobacteria following invasive procedures, such as ophthalmological, laparoscopic, arthroscopic, plastic, and cardiac surgeries, mesotherapy, and vaccination, have been detected in Brazil since 1998. Members of the Mycobacterium chelonae-Mycobacterium abscessus group have caused most of these outbreaks. As part of an epidemiological investigation, the isolates were typed by pulsed-field gel electrophoresis (PFGE). In this project, we performed a large-scale comparison of PFGE profiles with the results of a recently developed multilocus sequence typing (MLST) scheme for M. abscessus. Ninety-three isolates were analyzed, with 40 M. abscessus subsp. abscessus isolates, 47 M. abscessus subsp. bolletii isolates, and six isolates with no assigned subspecies. Forty-five isolates were obtained during five outbreaks, and 48 were sporadic isolates that were not associated with outbreaks. For MLST, seven housekeeping genes (argH, cya, glpK, gnd, murC, pta, and purH) were sequenced, and each isolate was assigned a sequence type (ST) from the combination of obtained alleles. The PFGE patterns of DraI-digested DNA were compared with the MLST results. All isolates were analyzable by both methods. Isolates from monoclonal outbreaks showed unique STs and indistinguishable or very similar PFGE patterns. Thirty-three STs and 49 unique PFGE patterns were identified among the 93 isolates. The Simpson's index of diversity values for MLST and PFGE were 0.69 and 0.93, respectively, for M. abscessus subsp. abscessus and 0.96 and 0.97, respectively, for M. abscessus subsp. bolletii. In conclusion, the MLST scheme showed 100% typeability and grouped monoclonal outbreak isolates in agreement with PFGE, but it was less discriminative than PFGE for M. abscessus.

Vision-Related Quality of Life in Patients With Keratoconus With Enantiomorphic Topography After Bilateral Intrastromal Corneal Ring Implantation.

PURPOSE: The aim of this study was to evaluate the quality of life (QOL) after intrastromal ring implantation in patients with keratoconus. METHODS: This was a prospective, randomized, interventional study. We analyzed 60 eyes of 30 patients aged 16 to 35 years who were treated at the Department of Ophthalmology and Visual Sciences, Federal University of São Paulo, Brazil. The Visual Function Questionnaire (VFQ-25) and Short-Form 36 Questionnaire (SF-36) were used before intracorneal ring segment (ICRS) implantation and at 3, 6, and 12 months after surgical intervention. RESULTS: The mean corrected visual acuity improved from a mean of 0.32 ± 0.2 logMAR (20/40) preoperatively to 0.14 ± 0.11 logMAR (20/25) 1 year postoperatively ( P = 0.001). The mean spherical equivalent varied from -7.24 ± 3.47 preoperatively to -4.13 ± 2.41 postoperatively ( P = 0.001). The overall composite score for the VFQ-25 improved from 55.1 preoperatively to 80.4 1 postoperatively ( P = 0.001). SF-36 showed statistically significant improvement in all scores. When analyzing the correlation between visual acuity and VFQ composite score, a significant correlation was found between both variables (Pearson correlation coefficient of -0.40, P = 0.001). CONCLUSIONS: Patients with keratoconus had increased psychological symptoms and lower QOL and improved psychosocial criteria associated with corneal remodeling and decreased visual dependence on others after surgery. Extrapolation of these data to the whole keratoconus population suggests that ICRS implantation could improve QOL in these patients.

Adhesion of Acanthamoeba on Scleral Contact Lenses According to Lens Shape.

Purpose: To investigate the adhesion of Acanthamoeba to scleral contact lens (ScCL) surface according to lens shape. Methods: Two strains of A. polyphaga (CDC:V062 and ATCC 30461) and one clinical Acanthamoeba isolate, were inoculated onto five contact lens (CL): one first-generation silicone hydrogel (SHCL; lotrafilcon B; adhesion control) containing plasma surface treatment; two ScCL (fluorosilicone acrylate) one containing surface treatment composed of plasma and the other containing plasma with Hydra-PEG, and two CL designed with a flat shape having the same material and surface treatments of the ScCL. Trophozoites that adhered to the lens's surfaces were counted by inverted optical light microscopy. Possible alterations of the lens surface that could predispose amoeba adhesion and Acanthamoeba attached to these lens surfaces were evaluated by scanning electron microscopy (SEM). Results: All strains revealed greater adhesion to the ScCL when compared with the flat lenses (P < 0.001). The clinical isolate and the ATCC 30461 had a higher adhesion (P < 0.001) when compared with the CDC:V062. A rough texture was observed on the surface of the lenses that have been examined by SEM. Also, SEM revealed that the isolates had a rounded appearance on the surface of the ScCL in contrast with an elongated appearance on the surface of the silicone hydrogel. Conclusions: The findings revealed that the curved shape of the ScCL favors amoeba adhesion.

A double-masked, sham-controlled trial of rose bengal photodynamic therapy for the treatment of fungal and acanthameoba keratitis: Rose Bengal Electromagnetic Activation with Green Light for Infection Reduction (REAGIR) Study.

Background: Infectious keratitis secondary to fungus or acanthamoeba often has a poor outcome despite receiving the best available medical therapy. In vitro Rose Bengal Photodynamic therapy (RB-PDT) appears to be effective against fungal and acanthamoeba isolates. 22,23 In one published series RB-PDT reduced the need for therapeutic penetrating keratoplasty in severe bacterial, fungal, and acanthameoba keratitis not responsive to medical therapy. Methods: This international, randomized, sham and placebo controlled 2-arm clinical trial, randomizes patients with smear positive fungal and acanthameoba and smear negative corneal ulcers in a 1:1 fashion to one of two treatment arms: 1) Topical antimicrobial plus sham RB-PDT or 2) Topical antimicrobial plus RB-PDT Discussion: We anticipate that RB-PDT will improve best spectacle corrected visual acuity and also reduce complications such as corneal perforation and the need for therapeutic penetrating keratoplasty. This study will comply with the NIH Data Sharing Policy and Policy on the Dissemination of NIH-Funded Clinical Trial Information and the Clinical Trials Registration and Results Information Submission rule. Our results will be disseminated via clinicaltrials.gov website, meetings, and journal publications. Our data will also be available upon reasonable request. Trial Registration: NCT, NCT05110001, Registered November 5, 2021. https://www.clinicaltrials.gov/study/NCT05110001.

In Vitro Evaluation of Rose Bengal Photoactivated by Custom-Built Green Light-Emitting Diode Source for Bacteria and Rapidly Growing Mycobacteria Inhibition.

Purpose: In vitro evaluation of rose bengal (RB) photoactivated by our custom-built green light-emitting diode (LED) source for the growth inhibition of bacterial strains and rapidly growing mycobacterial (RGM) isolates in infectious keratitis. Methods: Six corneal clinical bacteria isolates were included in this study: two Gram-positive bacteria (methicillin-resistant Staphylococcus aureus [MRSA] and Staphylococcus epidermidis), two Gram-negative bacteria (Pseudomonas aeruginosa and Serratia marcescens), and two RGM (Mycobacterium chelonae and Mycobacterium abscessus). Microorganisms were cultured and incubated at specific conditions and prepared in suspensions to adjust their concentration to 104 cells/mL. Different treatments were conducted in triplicates: Group I, no treatment; Group II, treated with 0.1% rose bengal alone (exposed to dark for 30 minutes); Group III, exposed to custom green LED for 30 minutes (12.87 J/cm2); and Group IV, treated with 0.1% rose bengal and exposed to custom green LED for 30 minutes. Agar plates were incubated at specific conditions and photographed after growth for pixel analyses. Results: Complete growth inhibition of all bacteria and RGM was observed in Group IV. MRSA and S. epidermidis in Group II also showed complete growth inhibition. Conclusions: The custom-built green LED presented good activity by photoactivating RB and inhibiting micro-organism growth. For the first time, we demonstrated the expressive growth inhibition effect of RB against S. epidermidis, RGM, and S. marcescens. Clinical treatment with RB may offer an alternate adjunct therapy for corneal surface infections. Translational Relevance: Validating in vitro the custom-built green LED encourages the clinical application for the treatment of infectious keratitis.

Scheimpflug-Derived Corneal Lower and Higher Order Aberrations Post Intrastromal Corneal Ring Segments for Keratoconus.

Intrastromal corneal ring segments (ICRS) improve corneal topographic symmetry and reduce corneal aberrations through regularization of the corneal surface, thereby functioning as a viable surgical intervention for patients with keratoconus. This study aims to evaluate changes in lower- (LOAs) and higher-order aberrations (HOAs) amongst varying pupil sizes pre- and post- ICRS implantation in keratoconus patients. We specifically investigate the impact of pupil size on total corneal HOAs up to the 6th order. Twenty-one eyes that underwent ICRS implantation were included in this prospective interventional study. LOAs and HOAs measurements at the 6 mm, 4 mm, and 2 mm pupil diameters were collected preoperatively and at 6 months postoperatively using the Zernicke analysis function on a Scheimpflug device. ICRS implantation demonstrated a statistically significant effect in vertical coma with a −0.23 reduction (p = 0.015) for a 4 mm pupil size and a −1.384 reduction (p < 0.001) for 6 mm, with no significant effect at 2 mm. Horizontal coma, astigmatism 0°, astigmatism 45°, trefoil 5th order 30°, and RMS HOA demonstrated significant reductions at 4 mm or 6 mm pupil sizes but not at 2 mm. Our analysis demonstrates a favorable effect of ICRS implantation on larger pupil sizes, suggesting the importance of pupil size as it correlates with HOAs reduction.

Vision Quality Questionnaire Assessment in Patients After Topography-Guided Photorefractive Keratectomy for Irregular Astigmatism Secondary to Radial Keratotomy.

Aim: To evaluate the vision-related quality of life with the National Eye Institute Refractive Error Quality of Life (NEI-RQL) questionnaire in patients with astigmatism secondary to radial keratotomy surgery who underwent topography-guided photorefractive keratectomy. Methods: Prospective non-randomized clinical trial. This study included 15 patients (30 eyes) aged > 21 years, mean age 55.1 (SD, 3.5) years, 53.3% female, with astigmatism ≤ - 6.00 D resulting from radial keratotomy, which could have been associated with hyperopia ≤ + 6.00 D. Photorefractive keratectomy with topography-guided custom ablation treatment was used in all cases. The patients answered the NEI-RQL questionnaire preoperatively and at 4 and 48 months after topography-guided photorefractive keratectomy. The following data were collected: age, sex and education level, pre-operative refraction data, visual acuity with or without correction, pachymetry, and keratometry. Results: There was a significant difference between pre-and postoperative NEI-RQL scores for the domains clarity of vision, near vision, far vision, diurnal fluctuation, activity limitations, glare, symptoms, correction dependence, appearance, and satisfaction with correction (p < 0.001). Conclusion: Topography-guided photorefractive keratectomy improved vision-related quality of life in patients with a history of irregular astigmatism secondary to radial keratotomy.

Impact of COVID-19 on corneal esthesiometry.

Individuals with suspected COVID-19 symptoms (n=202) were tested using nasopharyngeal RT-qPCR. All individuals underwent corneal esthesiometry measurements using the Cochet-Bonnet esthesiometer during their first visit; 50 participants underwent an additional measurement at a mean interval of 32.5 (17.8) days. COVID-19 was confirmed in 101 subjects (50%) using nasopharyngeal PCR. The mean time from symptom onset to disease diagnosis and corneal esthesiometry was 4.2 (2.1) days. Mean corneal esthesiometry findings based on the positive and negative PCR status indicated no statistical difference. This study demonstrated that COVID-19 had no effect on corneal esthesiometry in individuals with acute-phase COVID-19.

Rosai-Dorfman disease manifesting as an epibulbar ocular tumour.

The authors report a rare case of extranodal Rosai-Dorfman disease without systemic involvement. A 14-year-old girl presented with a slowly progressive, non-tender, well-circumscribed, perilimbal nodule in the right eye. Excisional biopsy was performed and histopathologic and immunohistochemical analysis established the diagnosis. Systemic evaluation revealed no other masses. After complete excision of the epibulbar lesion, the patient is asymptomatic and remains on regular follow up with no signs of recurrence. Rosai-Dorfman disease is an infrequent, benign histiocytic disorder that can rarely manifest as an exclusive extranodal mass. We report a case of solitary epibulbar Rosai-Dorfman disease, successfully treated with complete surgical excision of the lesion.

Conjunctivitis Related to not Severe COVID-19: A Case Report.

PURPOSE: The purpose of this article is to report a bilateral conjunctivitis case in a patient with confirmed 2019 novel coronavirus disease (COVID-19). CASE REPORT/OBSERVATIONS: A 24-year-old healthy man developed severe conjunctivitis in his right eye, followed by his left eye 4 days after fever and myalgia. He reported yellowish conjunctival discharge, foreign body sensation, redness, and tearing, and those symptoms were resolved in 10 days. Analyses of nasopharyngeal secretions identified SARS-CoV-2 by polymerase chain reaction (PCR). CONCLUSION: Mild COVID-19 can cause severe bilateral conjunctivitis. The ophthalmologist may be aware of conjunctival secretions, a possible path of infection, during eye checkup.

SARS-COV-2 and Ocular Surface: From Physiology to Pathology, a Route to Understand Transmission and Disease.

Coronaviruses gained public attention during the severe acute respiratory syndrome (SARS) outbreak in East Asia in 2003 and spread of Middle Eastern respiratory syndrome (MERS) in 2012. Direct human-to-human contact and droplet are the main methods of transmission. Viral stability in aerosols on different surfaces supports evidence on indirect viral acquisition from fomites through the mucous membranes of the mouth, nose, and eyes. Given the pandemic circumstances, the level of evidence in COVID-19 and ophthalmology regarding eye infection, conjunctival transmission, and viral shedding through tears is insufficient. Presently, conjunctival transmission of coronaviruses has not been confirmed and remains controversial. Considering the physiology of the lacrimal system and ocular surface, the eyes are considered an immunoprotective site, with several antiviral molecules and anti-inflammatory proteins. Nevertheless, they represent an interface with the exterior world and face daily putative aggressors. Understanding the host's ocular surface immunological and protective environment is crucial to clarify the potential of the conjunctiva as an entry route for SARS-CoV-2 and as part of this viral infection. We will discuss hypothetical ocular surface transmission mechanisms and related counterarguments addressed to both angiotensin-converting enzyme 2 receptors found on the conjunctival and corneal epithelia and lactoferrin, lysozyme, lipocalin and secretory IgA levels in the tear film. Hopefully, we will promote better understanding of this organ in COVID-19 infection and the potential transmission route that can be helpful in setting recommendations on best practices and protective guidelines to mitigate the disease spread.

Necrotizing Streptococcus pyogenes Infiltrating Conjunctiva and Tenon's Capsule: A Case Report.

We report a case of a patient with necrotizing infection of the conjunctiva and Tenon's capsule caused by Streptococcus pyogenes, a rare and atypical ophthalmologic condition. A 50-years-old male patient with acute red-eye, purulent discharge, and pain diagnosed with post-septal cellulitis presented with a yellowish and dense membrane covering the ocular surface with necrotic Tenon's capsule. Patient was hospitalized, and intravenous antibiotics were initiated (ceftriaxone and clindamycin). Topical antibiotics and corticosteroids were also administered, and the infection was eradicated in 2 weeks. Ancillary exams excluded rheumatologic involvement. Conjunctival culture confirmed Streptococcus pyogenes growth. Tenon's biopsy revealed unspecific acute inflammatory necrosis. This is an uncommon condition in daily ophthalmological clinic. Literature review reported 3 cases associated with previous ocular surgery.