Trends and Clinical Outcomes of Fungal Keratitis in Canada: a 20-year Retrospective Multicentre Study

PURPOSE

An increase in fungal and particularly filamentous keratitis has been observed in many geographic areas, mostly in contact lens wearers. This study seeks to characterize long-term trends in fungal keratitis in a continental climate area to provide guidance for diagnosis and treatment.

DESIGN

Retrospective multicentric case series.

METHODS

Cases of microbiology-confirmed fungal keratitis from 2003 to 2022 presenting to tertiary care centers across Canada were included. Charts were reviewed for patient demographics, risk factors, visual acuity, and treatments undertaken.

RESULTS

A total of 138 patients were identified: 75 had yeast keratitis while 63 had filamentous keratitis. Patients with yeast keratitis had more ocular surface disease (79% vs 28%) while patients with filamentous keratitis wore more refractive contact lenses (78% vs 19%). Candida species accounted for 96% of all yeast identified, while Aspergillus (32%) and Fusarium (26%) were the most common filamentous fungi species. The mean duration of treatment was 81 ± 96 days. Patients with yeast keratitis did not have significantly improved visual acuity with medical treatment (1.8 ± 1 LogMAR to 1.9 ± 1.5 LogMAR, p = 0.9980), in contrast to patients with filamentous keratitis (1.4 ± 1.2 LogMAR to 1.1 ± 1.3 LogMAR, p = 0.0093).

CONCLUSIONS

Fungal keratitis is increasing in incidence, with contact lenses emerging as one of the leading risk factors. Significant differences in the risk factors and visual outcomes exist between yeast keratitis and filamentous keratitis which may guide diagnosis and treatment.

Gender trends in Canadian medicine and surgery: the past 30 years

BACKGROUND

While the number of women entering medicine has steadily increased since the 1970s in Canada, the gender composition along each stage of the medical training pathway has not been comprehensively reported. We therefore sought to systematically examine the gender composition of students, residents, and practicing physicians over the past 30 years in Canada.

RESULTS

In this cross-sectional analysis of Canadian medical trainees including MD applicants (137,096 male, 169,099 female), MD students (126,422 male, 152, 967 female), MD graduates (29,413 male, 34,173 female), residents by the decade (24,425 male, 28,506 female) and practicing surgeons (total 7,457 male, 3,457 female), we find that increased female representation in medicine is not matched by representation in surgery, with the key being the specialty choice process. The likelihood of female applicants matriculating to medical school was less than male applicants in the 90s (OR 0.92, 95% CI 0.92-0.93), greater in the early 2000s (OR 1.03, 95% CI 1.03-1.04), and has since balanced out (OR 1.00, 95% CI 1.00-1.01), with medical school classes being nearly 60% female for the past two decades. Despite this, females have remained underrepresented in most surgical residency programs, with odds of female medical students entering surgical residency other than Ob/Gyn being about half that of male students (OR 0.56, 95% CI 0.44-0.71), resulting in a slow increase in practicing female surgeons of less than 0.5% per year in many surgical disciplines and projected parity decades or centuries in the future.

CONCLUSIONS

While undergraduate medical education has been majority female in Canada for nearly three decades, females remain greatly underrepresented in the physician workforce within surgical specialties. To build a representative medical workforce equipped to care for diverse patient populations, factors influencing the specialty choices of early career physicians will need to be examined and addressed.

From Hair Loss to Vision Loss: Minoxidil-Associated CRVO in a Young Female

Introduction

Central retinal vein occlusion (CRVO) is a common retinal vascular disorder that is most often seen in older adults and individuals with vascular risk factors.

Case Presentation

We report a case of CRVO with cystoid macular edema (CME) in a young, otherwise healthy patient taking minoxidil for hair loss. The patient had no known vascular risk factors, and a comprehensive coagulability workup was negative. The CRVO with CME resolved without intervention upon cessation of minoxidil.

Conclusion

Possible mechanisms for minoxidil-associated retinal vascular disorders are explored. Thorough medication histories and the consideration of possible adverse drug events in patients without traditional risk factors are recommended.

Macular hole repair: the effect of size and nonsupine posture on postoperative outcomes

Background

Postoperative face-down positioning (FDP) for up to 2 weeks is believed to be necessary for successful closure of macular holes. FDP, however, can be disabling and uncomfortable and is a major burden for elderly patients. The aim of this study was to investigate how nonsupine posturing and macular hole size affect anatomical and functional success of macular hole closure.

Methods

The medical records of patients with idiopathic macular holes who were treated surgically between 2016 and 2019 were reviewed retrospectively. Exclusion criteria included vitreomacular traction, previous retinal detachment, or chronic macular hole.

Results

A total of 115 eyes of 115 patients were included. Average age was 69.2 ± 8.2 years; 63 patients (55%) were female. Anatomical success was achieved in 108 patients (94%) with a single operation. In small holes (<400 μm), closure was seen in 98% of cases (95% CI, 94%-100%); in large holes (≥400 μm), 90% of cases (95% CI, 76%-94%). Visual acuity remained stable or improved in 108 patients (92%). Average preoperative best-corrected visual acuity was 1.02 ± 0.45, with an overall improvement of 5 lines postoperatively. Small holes and large holes improved, with an average of 3 versus 7 lines gained, respectively.

Conclusions

In this study cohort, favorable anatomical and functional outcomes were achieved without postoperative FDP. These outcomes are comparable to the traditional FDP approach.

Baseline Diabetes Knowledge Assessment Amongst Adults With Type 1 and Type 2 Diabetes Receiving Eye Care at a Tertiary Ophthalmic Centre in Canada

OBJECTIVES

The aim of this work was to assess the current state of baseline knowledge of diabetes and diabetic retinopathy (DR) in new patients referred to a tertiary retina service from their primary eye care provider.

METHODS

This single-centre, prospective, observational study included patients presenting to the retina clinic at the Hamilton Regional Eye Institute, a major tertiary referral centre, for their initial consultation for diabetes- or DR-associated complications. Upon recruitment into the study, patients were asked to complete a 35-item questionnaire regarding diabetes and associated complications. All data were coded and analyzed using statistical software.

RESULTS

A total of 98 patients participated in the study, which included 50 men and 48 women. Seventy-eight patients (79.6%) were Caucasian. We found that 56.1% (n=55) of the patients did not know the meaning of "HbA1C" (glycated hemoglobin) and only 26.5% of patients sampled were aware of their DR status. Bivariate analysis revealed that patients who had postsecondary education (p<0.001) or those who had education on complications of diabetes (p<0.05) were more likely to know their DR status. More importantly, it was found that 56.1% of patients expressed interest in a future diabetes seminar.

CONCLUSIONS

It is evident that a significant proportion of patients do not have adequate knowledge of diabetes or DR, and this is related to their level of education and lack of being taught about diabetes complications. Our findings may guide prevention initiatives by primary eye care providers and promote increased awareness about diabetes and DR for prevention of disease complications, including blindness.

Sexually transmitted infections and viral hepatitides in patients presenting for non-occupational HIV post-exposure prophylaxis: results of a prospective cohort study

Data evaluating the screening practices for viral hepatitides and sexually transmitted infections (STIs) in patients presenting for non-occupational HIV post-exposure prophylaxis (nPEP) care are limited. Screening practices and prevalences of viral hepatitides and STIs were evaluated in 126 patients presenting to a dedicated HIV prevention clinic for HIV nPEP. Three patients (2.4%) were diagnosed with chronic hepatitis C infection, 28 (22.2%) did not have surface antibodies in sufficient quantity to confer immunity to hepatitis B, and six (4.8%) were diagnosed with an STI. A multivariate regression model did not predict any demographic or clinical features predictive of HBV non-immunity. Beyond screening for HIV infection, evaluation for viral hepatitides and STIs is an important feature in the care of patients presenting for HIV nPEP.

Transitioning to HIV Pre-Exposure Prophylaxis (PrEP) from Non-Occupational Post-Exposure Prophylaxis (nPEP) in a Comprehensive HIV Prevention Clinic: A Prospective Cohort Study

The uptake of pre-exposure prophylaxis (PrEP) for HIV prevention remains low. We hypothesized that a high proportion of patients presenting for HIV non-occupational post-exposure prophylaxis (nPEP) would be candidates for PrEP based on current CDC guidelines. Outcomes from a comprehensive HIV Prevention Clinic are described. We evaluated all patients who attended the HIV Prevention Clinic for nPEP between January 1, 2013 and September 30, 2014. Each patient was evaluated for PrEP candidacy based on current CDC-guidelines and subjectively based on physician opinion. Patients were then evaluated for initiation of PrEP if they met guideline suggestions. Demographic, social, and behavioral factors were then analyzed with logistic regression for associations with PrEP candidacy and initiation. 99 individuals who attended the nPEP clinic were evaluated for PrEP. The average age was 32 years (range, 18-62), 83 (84%) were male, of whom 46 (55%) men who had have sex with men (MSM). 31 (31%) met CDC guidelines for PrEP initiation, which had very good agreement with physician recommendation (kappa=0.88, 0.78-0.98). Factors associated with PrEP candidacy included sexual exposure to HIV, prior nPEP use, and lack of drug insurance (p<0.05 for all comparisons). Combining nPEP and PrEP services in a dedicated clinic can lead to identification of PrEP candidates and may facilitate PrEP uptake. Strategies to ensure equitable access of PrEP should be explored such that those without drug coverage may also benefit from this effective HIV prevention modality.

MicroRNA-146 represses endothelial activation by inhibiting pro-inflammatory pathways

Activation of inflammatory pathways in the endothelium contributes to vascular diseases, including sepsis and atherosclerosis. We demonstrate that miR-146a and miR-146b are induced in endothelial cells upon exposure to pro-inflammatory cytokines. Despite the rapid transcriptional induction of the miR-146a/b loci, which is in part mediated by EGR-3, miR-146a/b induction is delayed and sustained compared to the expression of leukocyte adhesion molecules, and in fact coincides with the down-regulation of inflammatory gene expression. We demonstrate that miR-146 negatively regulates inflammation. Over-expression of miR-146a blunts endothelial activation, while knock-down of miR-146a/b in vitro or deletion of miR-146a in mice has the opposite effect. MiR-146 represses the pro-inflammatory NF-κB pathway as well as the MAP kinase pathway and downstream EGR transcription factors. Finally, we demonstrate that HuR, an RNA binding protein that promotes endothelial activation by suppressing expression of endothelial nitric oxide synthase (eNOS), is a novel miR-146 target. Thus, we uncover an important negative feedback regulatory loop that controls pro-inflammatory signalling in endothelial cells that may impact vascular inflammatory diseases.

Epstein-Barr nuclear antigen 1 contributes to nasopharyngeal carcinoma through disruption of PML nuclear bodies

Latent Epstein-Barr virus (EBV) infection is strongly associated with several cancers, including nasopharyngeal carcinoma (NPC), a tumor that is endemic in several parts of the world. We have investigated the molecular basis for how EBV latent infection promotes the development of NPC. We show that the viral EBNA1 protein, previously known to be required to maintain the EBV episomes, also causes the disruption of the cellular PML (promyelocytic leukemia) nuclear bodies (or ND10s). This disruption occurs both in the context of a native latent infection and when exogenously expressed in EBV-negative NPC cells and involves loss of the PML proteins. We also show that EBNA1 is partially localized to PML nuclear bodies in NPC cells and interacts with a specific PML isoform. PML disruption by EBNA1 requires binding to the cellular ubiquitin specific protease, USP7 or HAUSP, but is independent of p53. We further observed that p53 activation, DNA repair and apoptosis, all of which depend on PML nuclear bodies, were impaired by EBNA1 expression and that cells expressing EBNA1 were more likely to survive after induction of DNA damage. The results point to an important role for EBNA1 in the development of NPC, in which EBNA1-mediated disruption of PML nuclear bodies promotes the survival of cells with DNA damage.

Epstein-Barr virus (EBV) infects most people worldwide and is associated with several types of cancer due to its ability to induce cell proliferation. Only one viral protein, EBNA1, is expressed in all forms of EBV-associated tumors. Here, we have investigated whether EBNA1 directly contributes to the development of nasopharyngeal carcinoma (NPC), the most common EBV-associated tumor. We found that EBNA1 disrupts structures in the cell nucleus, called PML bodies, that are known to inhibit malignant transformation and to be important for cells to repair DNA that has been damaged due to exposure to carcinogenic agents. We show that EBNA1 interacts with and degrades the principal component of PML bodies. As a result, cells expressing EBNA1 are less able to repair their DNA and more likely to survive with DNA damage that could result in malignant transformation.

Regulation of the EBNA1 Epstein-Barr virus protein by serine phosphorylation and arginine methylation

The Epstein-Barr virus (EBV) EBNA1 protein is important for the replication and mitotic segregation of EBV genomes in latently infected cells and also activates the transcription of some of the viral latency genes. A Gly-Arg-rich region between amino acids 325 and 376 is required for both the segregation and transcriptional activation functions of EBNA1. Here we show that this region is modified by both arginine methylation and serine phosphorylation. Mutagenesis of the four potentially phosphorylated serines in this region indicated that phosphorylation of multiple serines contributes to the efficient segregation of EBV-based plasmids by EBNA1, at least in part by increasing EBNA1 binding to hEBP2. EBNA1 was also found to bind the arginine methyltransferases PRMT1 and PRMT5. Multiple arginines in the 325-376 region were methylated in vitro by PRMT1 and PRMT5, as was an N-terminal Gly-Arg-rich region between amino acids 41 and 50. EBNA1 was also shown to be methylated in vivo, predominantly in the 325-376 region. Treatment of cells with a methylation inhibitor or down-regulation of PRMT1 altered EBNA1 localization, resulting in the formation of EBNA1 rings around the nucleoli. The results indicate that EBNA1 function is influenced by both serine phosphorylation and arginine methylation.