Ocular manifestations of mpox.

PURPOSE OF REVIEW: To highlight the clinical features of mpox with an emphasis on ocular manifestations and to review treatment options for this re-emerging infectious disease. RECENT FINDINGS: Ocular involvement of mpox varies by clade. The most recent 2022 outbreak appears to be associated with fewer conjunctivitis cases compared to previous outbreaks. However, the ocular findings occurring during this newly emerging clade can be visually threatening and include cases of keratitis, rapidly progressing scleritis, and necrotizing periorbital rashes. SUMMARY: Ocular mpox is an important clinical feature of systemic mpox virus (MPXV) infection. Heightened clinical suspicion allows for a timely diagnosis and the initiation of antiviral treatment, when appropriate. Randomized clinical trials for mpox systemic and ocular treatment efficacy are lacking. Prior clinical experience with smallpox and in-vitro mpox data support the use of systemic antivirals such as tecovirimat, cidofovir, brincidofovir and topical use of trifluridine in ocular mpox management, though treatment-resistant infection can occur and portend a poor prognosis.

Human Conjunctival Transcriptome in Acanthamoeba Keratitis: An Exploratory Study.

PURPOSE: The purpose of this study was to identify conjunctival transcriptome differences in patients with Acanthamoeba keratitis compared with keratitis with no known associated pathogen. METHODS: The host conjunctival transcriptome of 9 patients with Acanthamoeba keratitis (AK) is compared with the host conjunctival transcriptome of 13 patients with pathogen-free keratitis. Culture and/or confocal confirmed Acanthamoeba in 8 of 9 participants with AK who underwent metagenomic RNA sequencing as the likely pathogen. Cultures were negative in all 13 cases where metagenomic RNA sequencing did not identify a pathogen. RESULTS: Transcriptome analysis identified 36 genes differently expressed between patients with AK and patients with presumed sterile, or pathogen-free, keratitis. Gene enrichment analysis revealed that some of these genes participate in several biologic pathways important for cellular signaling, ion transport and homeostasis, glucose transport, and mitochondrial metabolism. Notable relatively differentially expressed genes with potential relevance to Acanthamoeba infection included CPS1, SLC35B4, STEAP2, ATP2B2, NMNAT3, and AKAP12. CONCLUSIONS: This research suggests that the local transcriptome in Acanthamoeba keratitis may be sufficiently robust to be detected in the conjunctiva and that corneas infected with Acanthamoeba may be distinguished from the inflamed cornea where no pathogen was identified. Given the low sensitivity for corneal cultures, identification of differentially expressed genes may serve as a suggestive transcriptional signature allowing for a complementary diagnostic technique to identify this blinding parasite. Knowledge of differentially expressed genes may also direct investigation of disease pathophysiology and suggest novel pathways for therapeutic targets.

Incidence and Mitigation of Corneal Pseudomicrocysts Induced by Antibody-Drug Conjugates (ADCs).

Purpose of Review: This study is to highlight the incidence of corneal pseudomicrocysts in FDA-approved antibody-drug conjugates (ADCs), and success of preventive therapies for pseudomicrocysts and related ocular surface adverse events (AEs). Recent Findings: ADCs are an emerging class of selective cancer therapies that consist of a potent cytotoxin connected to a monoclonal antibody (mAb) that targets antigens expressed on malignant cells. Currently, there are 11 FDA-approved ADCs with over 164 in clinical trials. Various AEs have been attributed to ADCs, including ocular surface AEs (keratitis/keratopathy, dry eye, conjunctivitis, blurred vision, corneal pseudomicrocysts). While the severity and prevalence of ADC-induced ocular surface AEs are well reported, the reporting of corneal pseudomicrocysts is limited, complicating the development of therapies to prevent or treat ADC-related ocular surface toxicity. Summary: Three of 11 FDA-approved ADCs have been implicated with corneal pseudomicrocysts, with incidence ranging from 41 to 100% of patients. Of the six ADCs that reported ocular surface AEs, only three had ocular substudies to investigate the benefit of preventive therapies including topical steroids, vasoconstrictors, and preservative-free lubricants. Current preventive therapies demonstrate limited efficacy at mitigating pseudomicrocysts and other ocular surface AEs.

Prevalence, Patterns, and Predictors of SARS-CoV-2 RNA and Culturable Virus in Tears of a Case-Ascertained Household Cohort.

PURPOSE: To investigate the prevalence, patterns, and predictors of SARS-CoV-2 RNA and culturable virus in tears of a case-ascertained household cohort. DESIGN: Prospective, longitudinal case-ascertained household cohort identified through convenience sampling. METHODS: This analysis was restricted to individuals who were non-hospitalized, symptomatic, and tested positive for SARS-CoV-2 by nasal RT-PCR. Tears and anterior nasal biospecimens were serially collected throughout the acute period. Tears specimens were collected by the study staff using Schirmer test strips, and nasal specimens were self-collected. For both, SARS-CoV-2 RNA was quantified using qRT-PCR, and culturable virus was detected using presence of cytopathic effect (CPE) in tissue culture; positive CPE was confirmed by a qRT-PCR step. A series of cross-sectional unadjusted analyses were performed investigating the relationship between different sociodemographic determinants and biological factors associated with tears RNA positivity. RESULTS: Among the 83 SARS-CoV-2 infected participants, 10 (12%) had at least one RNA-positive tears specimen. Amongst these 10, 5 (50%) had concurrent presence of culturable virus, at a median of 7 days postsymptom onset (IQR: 4-7 days) (absolute range: 4-8 days). CONCLUSIONS: In this longitudinal cohort, we found evidence of culturable virus in the tears of a small proportion of nonhospitalized SARS-CoV-2 infected individuals. Current public health infection precautions do not account for transmission via tears, so these findings may improve our understanding of potential sources of SARS-CoV-2 transmission and contribute to developing future guidelines.

Locality is the strongest predictor of expert performance in image-based differentiation of bacterial and fungal corneal ulcers from India.

PURPOSE: This study sought to identify the sources of differential performance and misclassification error among local (Indian) and external (non-Indian) corneal specialists in identifying bacterial and fungal keratitis based on corneal photography. METHODS: This study is a secondary analysis of survey data assessing the ability of corneal specialists to identify acute bacterial versus fungal keratitis by using corneal photography. One-hundred images of 100 eyes from 100 patients with acute bacterial or fungal keratitis in South India were previously presented to an international cohort of cornea specialists for interpretation over the span of April to July 2021. Each expert provided a predicted probability that the ulcer was either bacterial or fungal. Using these data, we performed multivariable linear regression to identify factors predictive of expert performance, accounting for primary practice location and surrogate measures to infer local fungal ulcer prevalence, including locality, latitude, and dew point. In addition, Brier score decomposition was used to determine experts' reliability ("calibration") and resolution ("boldness") and were compared between local (Indian) and external (non-Indian) experts. RESULTS: Sixty-six experts from 16 countries participated. Indian practice location was the only independently significant predictor of performance in multivariable linear regression. Resolution among Indian experts was significantly better (0.08) than among non-Indian experts (0.01; P < 0.001), indicating greater confidence in their predictions. There was no significant difference in reliability between the two groups ( P = 0.40). CONCLUSION: Local cornea experts outperformed their international counterparts independent of regional variability in tropical risk factors for fungal keratitis. This may be explained by regional characteristics of infectious ulcers with which local corneal specialists are familiar.

Comprehensive Profile of Pathogens and Antimicrobial Resistance in Conjunctivitis Cases from Niger.

Infectious conjunctivitis outbreaks remain a public health burden. This study focuses on the pathogen and antimicrobial resistance (AMR) profiles identified in Niger. Sixty-two patients with acute infectious conjunctivitis who presented to health posts were enrolled from December 2021 to May 2022. Nasal and conjunctival swabs were obtained from each patient. Unbiased RNA deep sequencing (RNA-seq) was used to identify associated pathogens. A pathogen was identified in 39 patients (63%; 95% CI, 50-74). Of those, an RNA virus was detected in 23 patients (59%; 95% CI, 43-73). RNA viruses were diverse and included human coronaviruses (HCoVs): SARS-CoV-2, HCoV-229E, HCoV-HKU1, and HCoV-OC43. A DNA virus was identified in 11 patients (28%; 95% CI, 17-44). Of those, four patients had a coinfection with an RNA virus and two patients had a coinfection with both an RNA virus and a bacterium. DNA viruses were predominantly human herpesvirus (cytomegalovirus, Epstein-Barr virus, human herpesvirus 8) and human adenovirus species B, C, and F. Eighteen patients (46%; 95% CI, 32-61) had a bacteria-associated infection that included Haemophilus influenza, Haemophilus aegyptius, Staphylococcus aureus, Streptococcus pneumoniae, and Moraxella spp. Antimicrobial resistance determinants were detected in either the conjunctiva or nasal samples of 20 patients (32%; 95% CI, 22-45) and were found to be more diverse in the nose (Shannon alpha diversity, 1.12 [95% CI, 1.05-1.26] versus 1.02 [95% CI, 1.00-1.05], P = 0.01). These results suggest the potential utility of leveraging RNA-seq to surveil pathogens and AMR for ocular infections.

Pathogen Surveillance for Acute Infectious Conjunctivitis.

Importance: Acute infectious conjunctivitis is a common ocular condition with major public health consequences. Objective: To assess regional variations and microbial etiologies of acute infectious conjunctivitis to guide treatment. Design, Setting, and Participants: In this cross-sectional study, patients with presumed acute infectious conjunctivitis were enrolled in the study at 5 sites (Honolulu, Hawaii; Los Angeles, San Francisco, and San Diego, California; and Petah-Tikva, Israel) from March 2021 to March 2023. Patients with allergic or toxic conjunctivitis were excluded. Main Outcomes and Measures: Pathogens were identified by unbiased RNA deep sequencing. Results: In all, 52 patients (mean [range] age, 48 [7-80] years; 31 females [60%]) were enrolled at 5 sites (6 patients from Honolulu, 9 from San Diego, 11 from Los Angeles, 13 from San Francisco, and 13 from Petah-Tikva). RNA deep sequencing detected human adenovirus species D in one-quarter of patients (13 of 52). A wide range of pathogens, including human coronavirus 229E, SARS-CoV-2, and herpes simplex virus type 1, was also identified, as well as several bacteria and fungi. Moreover, 62% (32 of 52) of patients presented with purulent discharge, while only 8% (4 of 52) of patients had confirmed bacterial pathogens. Conclusion and Relevance: In this cross-sectional study, pathogens associated with acute infectious conjunctivitis varied between all 5 sites in the US and Israel. Purulent discharge was a common presenting sign in this study, with a low specificity for bacteria-associated conjunctivitis, suggesting that further diagnostic workup may be necessary to inform antibiotic stewardship. Additional research on cost-effectiveness of using RNA deep sequencing is needed to ascertain whether it is better to monitor patients clinically until resolution of disease.

Characterization of Infectious Keratitis in Opioid Users in a County Hospital Setting.

Purpose: To determine risk factors and clinical course of corneal ulcers in the setting of opioid use. Methods: A retrospective cohort study was performed of patients presenting with bacterial or fungal keratitis at a county hospital from 2010-2021. Subjects were separated into three groups: opioid drug users (heroin, methadone, fentanyl), non-opioid drug users, and non-drug users. 24 opioid users, 77 non-opioid drug users, and 38 non-drug users were included in the study. Chi-square and t-tests were used to compare hospitalization for corneal ulcer treatment; length of hospitalization; loss to follow-up; final best corrected visual acuity (BCVA); medication noncompliance; time to ulcer resolution; and visual disability (defined either by the legal limit for driving in California or the federal limit for blindness). Results: Opioid users had higher rates of unemployment (p=0.002), homelessness (p=0.018), and psychiatric conditions (p=0.024) compared with non-opioid and non-drug users. They had more severe presentations, with worse initial BCVA of the affected eye (p=0.003), larger ulcer size (p=0.023), and higher rates of individuals below the legal vision thresholds for driving (p=0.009) and blindness (p=0.033) at initial presentation. Opioid use was associated with increased rate of hospitalization (p<0.001), higher fortified antibiotic use (p=0.009), worse final BCVA of the affected eye (p=0.020), and increased rates of BCVA worse than the legal vision thresholds for driving (p=0.043) and blindness (p<0.001) on final presentation. Conclusions: Infectious keratitis associated with opioid use is associated with more severe presentations and poorer outcomes, including higher rates of visual disability.

Heterogenous pathogen profile associated with acute conjunctivitis in Nepal.

BACKGROUND: Infectious conjunctivitis is common in Nepal. MATERIALS AND METHODS: This prospective study recruited 60 patients with presumed acute infectious conjunctivitis from the B.P. Koirala Lions Center for Ophthalmic Studies in Kathmandu, Nepal. Swabs from the conjunctiva and anterior nares were processed for metagenomic RNA deep sequencing (RNA-seq). RESULTS: Pathogens were identified in 55% of cases. RNA viruses were the most common pathogen class identified. Severe acute respiratory syndrome coronavirus 2 was the most common RNA virus identified. CONCLUSIONS: Acute infectious conjunctivitis varies by location. Contrary to expectations, RNA viruses predominated. Repeat surveillance may be useful and RNA-seq allows for detection of the unexpected pathogen including RNA viruses.

Health Disparity Curricula for Ophthalmology Residents: Current Landscape, Barriers, and Needs.

Background Social determinants of health play a critical role in visual health outcomes. Yet, there exists no structured curriculum for ophthalmology residents to identify and address health disparities relevant to eye care or no a standard assessment of health disparities education within ophthalmology residency programs. This study aims to characterize current health disparity curricula in ophthalmology residency programs in the United States, determine resident confidence in addressing health disparities in the clinical setting, and identify perceived barriers and needs of program directors (PDs) and residents in this area. Design This was a cross-sectional survey study. Methods A closed-ended questionnaire with comments was distributed to the Accreditation Council for Graduate Medical Education-accredited ophthalmology residency PDs and residents in April 2021 and May 2022. The questionnaire solicited characteristics of any existing health disparity curricula, PD and resident perceptions of these curricula, and residents' experience with and confidence in addressing health disparities in the delivery of patient care. Results In total, 29 PDs and 96 residents responded. Sixty-six percent of PDs stated their program had a formal curriculum compared to fifty-three percent of residents. Forty-one percent of PDs and forty-one percent of residents stated their program places residents in underserved care settings for more than 50% of their training. Most residents (72%) were confident in recognizing health disparities. Sixty-six percent were confident in managing care in the face of disparities and fifty-nine percent felt they know how to utilize available resources. Residents were most concerned with the lack of access to resources to help patients. Forty-five percent of PDs felt the amount of time dedicated to health disparities education was adequate. Forty-nine percent of residents reported they felt the amount of training they received on health disparities to be adequate. The top barrier to curriculum development identified by PDs was the availability of trained faculty to teach. Time in the curriculum was a major barrier identified by residents. Conclusions Roughly half of ophthalmology residency programs who responded had a health disparity curriculum; however, both PDs and residents felt inadequate time is dedicated to such education. National guidance on structured health disparity curricula for ophthalmology residents may be warranted as a next step.

Role of Sex in Participation During Virtual Grand Rounds in Ophthalmology.

Importance: Sex disparities exist in academia. Female attendees consistently ask fewer questions in scientific meetings than male attendees, even when they constitute half of the audience. Objective: To assess the role of sex in participation during virtual grand rounds (GR) at a major academic center. Design, Setting, and Participants: In this prospective cohort study, attendees of the Department of Ophthalmology at the University of California, San Francisco, GR from April 2020 to April 2021 were included. All GR were held via a synchronous live video communication platform. During each GR session, a predesignated attendee collected the sex of all attendees, sex of the GR speaker, and sex of each individual who asked a question to the GR speaker in order of inquiry. The GR speakers and audience were unaware of the study. Data were analyzed from June 2021 to April 2023. Main Outcome and Measures: The main analysis assessed the association between being female and asking one of the first 3 questions. Results: A total of 31 virtual ophthalmology GR sessions were observed. The sex of the GR speaker was female in 13 of 31 sessions (42%). The mean (SD) percentage of audience sex at each of the GR sessions was 47% (0.05) female, 45% (0.06) male, and 8% (0.03) unknown. Male attendees were more likely to ask one of the first 3 questions compared with female attendees (prevalence ratio, 3.1; 95% CI, 2.1-4.5; P < .001). Conclusions and Relevance: Male attendees were more likely to ask questions during virtual ophthalmology GR compared with female attendees at an academic medical center. Strategies to encourage equal participation of sex in academic discourse should be encouraged.

Isolated Ocular Mpox without Skin Lesions, United States.

We report a case of a 53-year-old HIV-negative patient in San Francisco, California, USA, with no classic mpox prodromal symptoms or skin lesions who experienced fulminant, vision-threatening scleritis, keratitis, and uveitis. Deep sequence analysis identified monkeypox virus RNA in the aqueous humor. We confirmed the virus on the cornea and sclera by PCR.

Case Series: Unbiased Deep Sequencing Analysis of Acute Infectious Conjunctivitis in an Ambulatory Eye Center in Berkeley, California.

SIGNIFICANCE: Acute infectious conjunctivitis poses significant challenges to eye care providers. It can be highly transmissible, and because etiology is often presumed, correct treatment and management can be difficult. This study uses unbiased deep sequencing to identify causative pathogens of infectious conjunctivitis, potentially allowing for improved approaches to diagnosis and management. PURPOSES: This study aimed to identify associated pathogens of acute infectious conjunctivitis in a single ambulatory eye care center. CASE REPORTS: This study included patients who presented to the University of California Berkeley eye center with signs and symptoms suggestive of infectious conjunctivitis. From December 2021 to July 2021, samples were collected from seven subjects (ages ranging from 18 to 38). Deep sequencing identified associated pathogens in five of seven samples, including human adenovirus D, Haemophilus influenzae , Chlamydia trachomatis , and human coronavirus 229E. CONCLUSIONS: Unbiased deep sequencing identified some unexpected pathogens in subjects with acute infectious conjunctivitis. Human adenovirus D was recovered from only one patient in this series. Although all samples were obtained during the COVID-19 pandemic, only one case of human coronavirus 229E and no SARS-CoV-2 were identified.

Deep sequencing analysis of acute conjunctivitis in Burkina Faso, Africa.

BACKGROUND: Seasonal and epidemic conjunctivitis (pink eye) infections are highly contagious and impose a significant economic burden worldwide. Long-term visual impairment can occur. METHODS: This study used metagenomic deep sequencing to evaluate pathogens causing acute infectious conjunctivitis in Burkina Faso. RESULTS: We found that pathogens causing conjunctivitis in Burkina Faso are diverse, with human adenoviruses responsible for a small fraction of the samples tested. CONCLUSIONS: These results are unexpected and suggest the importance of regional surveillance.

Longitudinal Use of Telehealth During the COVID-19 Pandemic and Utility of Asynchronous Testing for Subspecialty-Level Ophthalmic Care.

Importance: Telehealth in ophthalmology has traditionally focused on preventive disease screening with limited use in outpatient evaluation. The unique conditions of the COVID-19 pandemic afforded the opportunity to evaluate different implementations of teleophthalmology at scale, providing insight into expanding teleophthalmology care. Objective: To compare telehealth use in ophthalmology with other specialties and assess the feasibility of augmenting ophthalmic telehealth encounters with asynchronous testing during the COVID-19 pandemic. Design, Setting, and Participants: This quality improvement study evaluated retrospective, longitudinal, observational data from the first 18 months of the COVID-19 pandemic (January 1, 2020, through July 31, 2021) for 881 080 patients receiving care from outpatient primary care, cardiology, neurology, gastroenterology, surgery, neurosurgery, urology, orthopedic surgery, otolaryngology, obstetrics/gynecology, and ophthalmology clinics of the University of California, San Francisco. Asynchronous testing was evaluated for teleophthalmology encounters. Interventions: A hybrid care model wherein ophthalmic testing data were acquired asynchronously and used to augment telehealth encounters. Main Outcomes and Measures: Telehealth as a percentage of total volume of ambulatory care and use of asynchronous testing for ophthalmic conditions. Results: The volume of in-person outpatient visits dropped by 83.3% (39 488 of 47 390) across the evaluated specialties at the onset of shelter-in-place orders for the COVID-19 pandemic, and the initial use of telehealth increased for these specialties before stabilizing over the 18-month study period. In ophthalmology, telehealth use peaked at 488 of 1575 encounters (31.0%) early in the pandemic and returned to mostly in-person visits as COVID-19 restrictions lifted. Elective use of telehealth was highest in gastroenterology, urology, neurology, and neurosurgery and lowest in ophthalmology. Asynchronous testing was combined with 126 teleophthalmology encounters, resulting in change of clinical management for 32 patients (25.4%) and no change for 91 (72.2%). Conclusions and Relevance: Telehealth increased across various specialties during the COVID-19 pandemic. Combining teleophthalmic visits with asynchronous testing suggested that this approach is feasible for subspecialty-level evaluation. Additional study is needed to evaluate whether asynchronous testing outside the same institution could provide an effective and lasting approach for expanding the reach of ophthalmic telehealth.

Antiamoebic Susceptibility in Acanthamoeba Keratitis: Comparison of Isolates From South India and Northern California.

PURPOSE: Outcomes of Acanthamoeba keratitis are often worse in India than in the United States. The goal of this study was to determine whether antiamoebic susceptibility patterns were different when comparing Acanthamoeba isolates from India with those of the United States. METHODS: Acanthamoeba isolates were obtained from corneal scrapings of 43 patients with infectious keratitis seen at the Francis I. Proctor Foundation (N = 23) and Aravind Eye Hospital (N = 20) from 2008 through 2012 and plated on growth media. A previously described minimum cysticidal concentration (MCC) assay was performed by a single laboratory technician to assess susceptibility to 5 antiamoebic agents for all isolates. Testing was conducted in triplicate, with the median MCC chosen for analyses. RESULTS: The MCC (µg/mL) of polyhexamethylene biguanide was 6.25 [IQR 5.47-12.5] for Aravind isolates and 6.25 [IQR 6.25-9.375] for Proctor isolates ( P = 0.75), corresponding values were 6.25 [IQR 3.125-6.25] and 3.125 [IQR 3.125-9.375] for chlorhexidine ( P = 0.81), 2500 [IQR 2500-5000] and 5000 [IQR 1250-20,000] for voriconazole ( P = 0.25), 15.6 [IQR 15.6-39.0625] and 15.6 [IQR 15.6-31.25] for hexamidine ( P = 0.92), and 15.6 [IQR 7.81-15.6] and 15.6 [IQR 7.81-31.25] for propamidine ( P = 0.42). CONCLUSIONS: This study found no statistically significant differences in antiamoebic susceptibility of Indian versus US samples from Acanthamoeba keratitis clinical isolates. These findings suggest that differences in antiamoebic susceptibility are likely not responsible for differential outcomes in Acanthamoeba keratitis between the 2 locations.

Pathogen Profiles of Infectious Conjunctivitis in Ho Chi Minh City, Vietnam.

Purpose: Conjunctivitis epidemics and pandemics remain a global burden. This study aims to comprehensively identify pathogens associated with conjunctivitis in Vietnam. Methods: Patients with acute conjunctivitis presented to an outpatient clinic in Ho Chi Minh City, Vietnam, were enrolled from September 2022 to March 2023. Swabs were obtained from conjunctiva and anterior nares of all patients. Unbiased RNA deep sequencing (RNA-seq) was used to identify any replicating pathogens in the samples. Results: Samples from 35 patients were analyzed. A pathogen was identified in 80% of the patients. 72% (95% confidence interval: 54% to 85%) were infected with either HAdV-D or HAdV-B. RNA viruses detected were rhinoviruses and human coronavirus 229E. Bacteria etiologies included Streptococcus pneumoniae, Hemophilus influenza, and Pseudomonas spp. One patient had co-infection of rhinovirus A and HAdV-B. Vittaforma corneae, a fungus, was identified in one patient. Corneal sub-epithelial infiltrates, pseudomembranes, or pre-auricular lymphadenopathy were not reported in any patient. Conclusions: Human adenoviruses are the common circulating pathogens associated with infectious conjunctivitis in Vietnam. HAdV species, however, appear to vary between geographic locations within Vietnam. Other under-recognized pathogens identified in this study, such as RNA viruses, suggest broader pathogen surveillance may be beneficial.

Ocular Rosacea microBiome Study (ORBS)-sub-microbial versus antibiotic dosing of doxycycline versus placebo in treatment of symptomatic ocular rosacea: study protocol for a parallel-arm randomized clinical trial.

BACKGROUND: Ocular rosacea is common and is often managed with long-term antibiotic treatment. Doxycycline is the most commonly selected antibiotic for the treatment of rosacea. As there is no established standard of care treatment dose for rosacea, prescribed doses of doxycycline vary widely. The FDA classifies 40 mg daily dose of doxycycline for ocular rosacea as sub-microbial in comparison to an antibiotic dose of 200 mg daily. However, this "sub-microbial" dose has never been evaluated in patients with ocular rosacea, and even the sub-microbial dose has potential to alter systemic mucosa flora. Here, we present a randomized controlled trial using RNA sequencing to fully characterize the impact of sub-microbial antibiotic dosing of doxycycline on antimicrobial resistance and bacterial composition of the ocular and gut flora. METHODS: In a triple-masked parallel randomized control trial, patients with ocular rosacea will be randomized to three arms: a 40-mg dose of doxycycline, a 200-mg antibiotic dose of doxycycline, or placebo. Collected rectal and lower eyelid samples will be compared for frequency of antimicrobial resistance genetic determinants and microbiome diversity. A subjective ocular surface disease index survey and objective tear breakup time measurement will be determined. DISCUSSION: These results will enhance our understanding of the overall systemic impact of long-term systemic sub-microbial antibiotic dosing for the treatment of chronic recurrent ocular inflammatory diseases. TRIAL REGISTRATION: This trial was registered on ClinicalTrials.org (NCT05296837) on March 22, 2022.