The Impact of Vaping on the Ocular Surface: A Systematic Review of the Literature.

Background: The use of electronic cigarettes has become increasingly popular in recent years. However, the impact that electronic cigarettes have on the ocular surface is not well known. Therefore, the aim of this review is to explore the current literature on the acute and chronic sequelae of electronic cigarettes on the ocular surface. Methods: A systematic review of the literature was undertaken by keyword searching on the Embase, Medline, and Web of Science databases. Articles identified through the search underwent title/abstract screening, full-text screening, and data extraction. Results: A total of 18 studies were included in this review. Non-intended ocular surface exposures and intended exposures on the ocular surface were found to be associated with the use of electronic cigarettes. Conclusions: The impact of vaping on the ocular surface is not benign. There are significant risks that vaping can pose to the ocular surface. Hence, it is necessary to develop appropriate risk communication tools given the increasing popularity of this activity. Additionally, future long-term studies are needed to better understand the long-term impacts of vaping on the ocular surface given the lack of current data.

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.

Closing the Gender Gap Among Canadian Ophthalmology Societies.

OBJECTIVE: To evaluate gender distribution in Canadian ophthalmology societies' leadership and to determine associations between gender, academic productivity, and institutional rank. METHODS: We identified members and assessed their gender composition using publicly available updated webpages. SCOPUS database was used to gather research metrics. RESULTS: In this study, data was collected from 12 Canadian ophthalmology societies, which included 277 executive committee members. Of these, 70.5% (196) were male and 29.1% (81) were female (p < .0001). Males were significantly more prevalent in presidential leadership roles (39 males vs. 23 females, p = .02), while females were more represented in other leadership categories (77 females vs. 61 males, p = .03). The Canadian Ophthalmological Society (COS) showed an upward trend in female representation from 19.2% in 2016 to 42.3% in 2021. Research productivity showed a positive correlation with society leadership rank, with a correlation coefficient of 0.732 for the m-index (p < .001) and 0.356 for the h-index (p < .05). Academic rank was also positively correlated with society leadership rank, with a correlation coefficient of 0.536 (p < .001). There was no significant difference in h-index (12.7 ± 1.0 for males vs. 13.8 ± 1.5 for females, p = .85) or number of publications (48.6 ± 5.1 for males vs. 60.0 ± 11.3 for females, p = .83) between male and female executive members, but females had a higher m-index (0.67 ± 0.05) compared to males (0.58 ± 0.03, p < .05). In academic rank, males were more likely to be associate professors (25% vs. 5% for females, p = .0001) or instructors (14.8% vs. 6.3% for females, p = .05), while a higher proportion of females held assistant professor positions (47.5% for females vs. 30.1% for males, p = .006). CONCLUSION: In this study, we found that males were more prevalent in executive positions, particularly in presidential roles among Canadian ophthalmology societies. The gender distribution in leadership reflected the gender composition of practicing ophthalmologists in Canada. There was a positive correlation between research productivity and society rank, as well as academic position and society rank. Male and female executive members had similar h-index and number of publications, but females had a higher m-index. These findings highlight the need for continued efforts to address gender disparities in ophthalmology leadership.

Global impact of COVID-19 on corneal donor tissue harvesting and corneal transplantation.

Introduction: The purpose of this review is to consolidate and examine the available literature on the coronavirus disease 2019 pandemic and its effect on corneal transplantation and eye banking. Methods: A primary literature search was conducted using the PubMed (Medline) database with keywords and MeSH terms such as "corneal transplantation," "eye banks," "keratoplasty" and then were combined with COVID-19. Relevant articles through September 2022 were assessed and 25 articles were included in this review. Results: Donor tissue volumes declined globally during lockdown periods due to a lower number of referrals and tighter tissue screening guidelines. Rates of elective surgeries decreased in the lockdown period compared to respective periods in previous years. However, changes in rates of emergency procedures were not uniform across different regions. Moreover, rates of different elective corneal grafts [i.e., penetrating keratoplasty (PK), endothelial keratoplasty (EK), or anterior lamellar keratoplasty (ALK)] were affected differently with the pattern of change being dependent on region-specific factors. Conclusion: Both donor tissue volumes and rates of corneal transplant procedures were affected by lockdown restrictions. The underlying etiology of these changes differed by region. Examining the range of impact across many countries as well as the contributing factors involved will provide guidance for future global pandemics.

Outcomes of XEN Stent in Patients With Glaucoma and Previous Corneal Transplantation.

PRCIS: The XEN stent safely and effectively controls intraocular pressure in select patients with history of corneal transplantation. PURPOSE: Glaucoma is a common complication after corneal transplantation and can be difficult to manage in these patients. This study reports outcomes of XEN stent implantation in eyes with glaucoma in the setting of previous corneal transplantation. PATIENTS AND METHODS: Noncomparative retrospective case series including eyes with a history of corneal transplantation and subsequent XEN stent implantation by a single glaucoma surgeon in Surrey, British Columbia, between 2017 and 2022. The analysis included patient demographics, pre and postoperative intraocular pressure (IOP), pre and postoperative glaucoma medications, peri and postoperative complications and interventions, and incidence of repeat corneal transplantation and additional glaucoma procedures to control IOP. RESULTS: Fourteen eyes with previous cornea transplantation underwent XEN stent implantation. Mean age was 70.1 years (range: 47-85 y). Mean follow-up was 18.2 months (range: 1.5-52 mo). The most common glaucoma diagnosis was secondary open angle glaucoma (50.0%). There was a significant reduction in IOP and the number of glaucoma agents at all postoperative time points ( P < 0.05). IOP decreased from 32.7 ± 10.0 mm Hg at baseline to 12.5 ± 4.7 mm Hg at the most recent follow-up. Glaucoma agents decreased from 4.0 ± 0.7 to 0.4 ± 1.0. Two eyes required additional glaucoma surgery to control IOP, with an average time to reoperation of 7 weeks. Two eyes underwent repeat corneal transplantation, with an average time to reoperation of 23.5 months. CONCLUSIONS: In selected patients with previous corneal transplants and refractory glaucoma, the XEN stent was safely implanted and effectively reduced IOP in the short term.

Visual Outcomes of Cataract Surgery in Patients With Keratoconus Using Toric and Non-toric Lenses.

PURPOSE: To compare the accuracy and outcomes of different intraocular lens (IOL) power calculation formulas in eyes with keratoconus undergoing cataract surgery with toric and non-toric IOLs. METHODS: This was a consecutive retrospective case series study including patients from the Cornea Service at the Department of Ophthalmology and Visual Sciences at the University of British Columbia, Vancouver, Canada, from 2000 to 2020. Keratoconus was diagnosed based on corneal topography and clinician opinion. Patients who underwent topography-guided photorefractive keratectomy, intracorneal ring segments implantation, or corneal transplant were excluded. The manifest spherical equivalent, prediction errors, and median absolute errors were calculated. Descriptive statistics were expressed as mean ± standard deviation. RESULTS: There were 160 eyes from 101 patients; 136 eyes received non-toric lenses and 24 eyes received toric lenses. Most patients had mild disease (< 48.00 diopters [D]) when stratified by steep keratometry values. Patients with severe disease (> 53.00 D) were significantly more hyperopic following surgery (P < .05). The Barrett Universal II (0.26 D, inter-quartile range [IQR] = 0.4), Holladay 2 (0.31, IQR = 1.2), and SRK/T (0.42, IQR = 0.86) formulas had the lowest median absolute error. The postoperative prediction error following toric lens insertion was not significantly different than following non-toric lens insertion, and the mean absolute astigmatism was significantly reduced with toric lenses. CONCLUSIONS: The Barrett Universal II, Holladay 2, and SRK/T were the most accurate IOL power calculation formulas in patients with keratoconus undergoing cataract surgery. Hyperopic surprise was increased in severe keratoconus. Toric IOLs may be considered in patients with mild keratoconus. [J Refract Surg. 2023;39(5):319-325.].

Superior limbic keratoconjunctivitis: Update on pathophysiology and management.

Superior limbic keratoconjunctivitis (SLK) is an under-recognized condition characterized by a final common pathologic presentation of superior conjunctival and limbal inflammation and staining. Existing literature attributes both microtrauma and local inflammation, frequently in the setting of tear film insufficiency, as the underlying mechanisms that lead to a self-perpetuating pathologic process dependent in on inflammatory cells and signaling. Effective treatments act by targeting inflammation and by mitigating mechanical stressors. This critical review discusses the latest in our understanding of the pathophysiology of SLK and how it guides our treatment strategies.

Long-term outcomes of fornix reconstruction and cicatricial entropion repair in ocular mucous membrane pemphigoid and drug-related secondary pemphigoid.

OBJECTIVE: To investigate the long-term outcomes of fornix reconstruction and cicatricial entropion repair in patients with ocular mucous membrane pemphigoid (MMP) and secondary MMP. METHODS: Retrospective chart review of patients with MMP undergoing either fornix reconstruction (with amniotic membrane or buccal mucosal graft) or Wies cicatricial entropion repair between January 1, 2000, and September 1, 2020. Patients had a positive mucosal biopsy and (or) clinical features of MMP or secondary MMP. The primary outcome was overall success of fornix reconstruction based on fornix depth maintenance at latest follow-up. Secondary outcomes included resolution of trichiasis, visual acuity, and improvement of subjective symptoms. RESULTS: Eight patients (10 eyes) with a diagnosis of MMP (3 males and 5 females; median age, 71 years) and 4 patients (4 eyes) with a diagnosis of secondary MMP (2 females and 2 male; median age, 87 years) were enrolled. Mean follow-up was 22.7 months (range, 0.3-87.5 months) for MMP patients and 15.4 months (range, 3.0-43.9 months) for secondary MMP patients. For MMP eyes, 30.0% underwent fornix reconstruction, 60.0% underwent entropion repair, and 10.0% received both. Re-formation of symblepharon and loss of fornix depth occurred in all MMP eyes at an average of 6.4 ± 7.0 months postoperatively, and trichiasis recurred in all patients at the last follow-up visit. In secondary MMP patients, 75.0% of the eyes showed recurrence of symblepharon, and 66.7% re-formed trichiasis. Both MMP and secondary MMP patients had short-term symptom improvements. CONCLUSIONS: Fornix reconstruction and cicatricial entropion repair in our cohort of MMP and secondary MMP patients resulted in short-term symptomatic improvement, but recurrence was seen, on average, at 6 months postoperatively.

Impact of the use of anti-glaucoma medications on the risk of herpetic keratitis recurrence.

PURPOSE: Numerous case reports have associated anti-glaucoma medications with recurrence of herpes simplex virus (HSV) and herpes zoster virus (HZV) keratitis. The aim of our study was to determine whether different anti-glaucoma agents are associated with recurrence of herpetic keratitis. METHODS: This was a retrospective cohort study using health databases from a Canadian province from January 2001 to December 2012. A new cohort of users on topical prostaglandins (PGs), beta blockers (BBs), alpha-2 agonists (AAs) and carbonic anhydrase inhibitors (CAIs) was created. The date of the third anti-glaucoma drug dispensation within 90 days was deemed the index date of the case. Herpetic keratitis events, as defined by an ICD-9/10 code for HSV or HZV keratitis, or the dispensation of an anti-viral medication by either an ophthalmologist or an optometrist, were examined prior to and following the index date. Risk ratios (RRs) were computed to compare the risk of HSV/HZV keratitis among the PG, BB, AA, and CAI groups individually and collectively while adjusting for age and sex. RESULTS: Among 19,986 users of glaucoma medications identified, there were 684 cases of HSV/HZV keratitis. There was no increased risk of HSV/HZV keratitis recurrence for any of the four glaucoma medications classes individually or collectively when adjusted for age and sex. There was also no increased risk for redeveloping either HSV keratitis only or HZV keratitis only amongst all anti-glaucoma users. CONCLUSION: There is no association between the use of topical ocular hypotensive therapies and HSV/HZV keratitis recurrence. Further studies are needed to confirm these findings.

Pathophysiology of Corneal Endothelial Cell Loss in Dry Eye Disease and Other Inflammatory Ocular Disorders.

PURPOSE: Dry eye disease (DED) and other inflammatory ocular disorders have been reported to be associated with decreased corneal endothelial cell density (CECD), however the mechanism of underlying endothelial cell loss remains unknown. METHODS: We conducted a comprehensive literature search of English-written publications on dry eye disease, corneal endothelial cell loss, Sjögren's syndrome, and Graft Vs Host Disease (GVHD), to review the effects of DED and other inflammatory ocular surface conditions on CECD. RESULTS: A total of 78 studies were included in our study. Loss of corneal neurotrophic support, cytotoxic stress, and a heightened immune response, all of which may occur secondarily to a common causative agent such as inflammation, are major contributors to reduced CECD. CONCLUSION: More studies are needed to determine how the interrelated pathways of altered corneal nerve function and upregulated expression of inflammatory activity influence corneal endothelial cell loss.

Potential role of extracellular granzyme B in wet age-related macular degeneration and fuchs endothelial corneal dystrophy.

Age-related ocular diseases are the leading cause of blindness in developed countries and constitute a sizable socioeconomic burden worldwide. Age-related macular degeneration (AMD) and Fuchs endothelial corneal dystrophy (FECD) are some of the most common age-related diseases of the retina and cornea, respectively. AMD is characterized by a breakdown of the retinal pigment epithelial monolayer, which maintains retinal homeostasis, leading to retinal degeneration, while FECD is characterized by degeneration of the corneal endothelial monolayer, which maintains corneal hydration status, leading to corneal edema. Both AMD and FECD pathogenesis are characterized by disorganized local extracellular matrix (ECM) and toxic protein deposits, with both processes linked to aberrant protease activity. Granzyme B (GrB) is a serine protease traditionally known for immune-mediated initiation of apoptosis; however, it is now recognized that GrB is expressed by a variety of immune and non-immune cells and aberrant extracellular localization of GrB substantially contributes to various age-related pathologies through dysregulated cleavage of ECM, tight junction, and adherens junction proteins. Despite growing recognition of GrB involvement in multiple age-related pathologies, its role in AMD and FECD remains poorly understood. This review summarizes the pathophysiology of, and similarities between AMD and FECD, outlines the current knowledge of the role of GrB in AMD and FECD, as well as hypothesizes putative contributions of GrB to AMD and FECD pathogenesis and highlights the therapeutic potential of pharmacologically inhibiting GrB as an adjunctive treatment for AMD and FECD.

Risk of Ocular Adverse Events With Taxane-Based Chemotherapy.

Importance: Taxane-based chemotherapy agents, such as docetaxel and paclitaxel, are used for treating a wide range of cancers. Although much has been published on adverse events related to taxanes, data on ocular outcomes with these very important drugs are scant. Objective: To quantify the risk of 3 mutually exclusive ocular adverse events of epiphora, cystoid macular edema (CME), and optic neuropathy with taxane-based chemotherapy agents by undertaking a large pharmacoepidemiologic study. Design, Setting, and Participants: This retrospective cohort study design used a private health-claims database from the US that captures health information of more than 150 million enrollees. The study team created a cohort of new users of women with cancer who were taking taxane-based chemotherapy (docetaxel or paclitaxel) and new users of tamoxifen as controls. Study members were observed to the first incidence of each of the 3 mutually exclusive outcomes. An analysis of taxane-only users was also undertaken. Exposure: Tamoxifen (unexposed) and taxanes (ie, paclitaxel and docetaxel) as the exposed. Main Outcomes and Measures: First diagnosis of (1) epiphora, (2) cystoid macular edema (CME), or (3) optic neuropathy ascertained using International Statistical Classification of Diseases and Related Health Problems, Ninth Revision or International Statistical Classification of Diseases and Related Health Problems, Tenth Revision. Results: Among the 18 219 users in the epiphora analysis and optic neuropathy analysis, there were 1824 taxane users (paclitaxel and docetaxel) (age, mean [SD], 62.1 [12.7] years) and 16 395 tamoxifen users (age, mean [SD], 54.6 [12.8] years), respectively. The crude hazard ratio (HR) for epiphora was 5.55 (95% CI, 2.99-10.29) and adjusted HR was 5.15 (95% CI, 2.79-9.54). For optic neuropathy, the crude HR was 4.43 (95% CI, 1.10-17.82) and the adjusted HR was 4.44 (95% CI, 1.04-18.87). Among the 18 433 users in the CME analysis, there were 1909 taxane users (paclitaxel and docetaxel) (age, mean [SD], 62.5 years) and 16 524 tamoxifen users (age, mean [SD], 54.6 years). The crude HR for CME comparing taxane users with tamoxifen users was 1.37 (95% CI, 0.72-2.60) and adjusted HR was 1.33 (95% CI, 0.70-2.53). The HRs for epiphora and CME in the taxane cohort during the time of exposure compared with the period prior to use of the drugs were 2.86 (95% CI, 1.11-7.39) and 2.27 (95% CI, 0.68-7.54), respectively. Conclusions and Relevance: In a cohort of women who were using taxane chemotherapy agents, there was an association with elevated risk for epiphora, CME, and optic neuropathy. Ophthalmologists and oncologists should be aware of these adverse events in women with breast cancer who receive these drugs.

Delayed Topographical and Refractive Changes Following Corneal Cross-Linking for Keratoconus.

Background: The aim of this study was to analyze the long-term topographic and refractive outcomes of corneal cross-linking (CXL) in keratoconus. Methods: We used a retrospective observational study of patients with keratoconus who underwent CXL with a minimum follow-up of 5 years. Patients' refractive and topography data (corrected distance visual acuity, sphere, cylinder, average and maximum keratometry, and corneal aberrations) were collected. Results: A total of 112 patients/150 eyes (mean age: 33.2 ± 10.7 years; range: 13−61) were included. The mean follow-up was 5.87 ± 1.35 years (range: 5−10). At the last follow-up visit, an improvement in CDVA, spherical and cylindrical refraction, average and steepest keratometry, and corneal aberrations were observed (p < 0.05), with the exception of trefoil. At the last visit, 49 (34.8%) and 31 (22.0%) eyes had an improvement beyond 1D in their spherical and cylindrical power, respectively, and 43 (28.7%) eyes had a flattening of their steepest keratometry. Progressive improvement over time was observed for spherical refraction; max and mean-K; as well as corneal RMS, total, high, coma, and spherical aberrations (p < 0.05). More severe disease at the baseline correlated with an improvement in corneal aberrations over time. Conclusions: In addition to a progressive improvement in refractive and keratometric indices, corneal aberrations also demonstrate a steady decline with long-term follow-up after CXL, which was more pronounced in more severe patients.

Thygeson's superficial punctate keratitis.

PURPOSE: Thygeson's superficial punctate keratitis (TSPK) is a chronic and recurrent corneal epitheliopathy. Although first described more than 70 years ago, the precise etiological mechanism and optimal treatment approach for TSPK has not been established. In this paper, we present an up-to date review of the literature and propose a step-by-step management protocol. METHOD: A literature search was done on PubMed using keywords including Thygeson's superficial punctate keratitis, punctate keratitis, etiology, management, and treatment. The literature was reviewed and reported. RESULTS: The main findings of this review include a summary of the main theories behind the cause TSPK; although topical corticosteroids remain the treatment of choice, long-term risks associated with these agents and recent studies have revealed immunomodulatory agents as promising treatment adjuvants or alternatives for TSPK; surgical interventions such as PRK/PTK have been utilized in selected refractory cases; finally we propose a treatment protocol based the best available evidence and clinical experience. CONCLUSION: Although the clinical features of TSPK have been well described, the specific cause of TSPK remains inconclusive. Mechanisms proposed including viral infection, immune-mediated, and immune responses to viral infection but require further investigation. More prospective randomized clinical trials comparing efficacy of corticosteroids, tacrolimus, and cyclosporine A (CSA) are required. More evidence is required for surgical interventions such as PRK/PTK.

Canadian demand and access to corneal transplantation: a provincial comparison.

To gather information from stakeholders involved in corneal donation and transplantation to inform discussion at the "National Consensus Forum on Improving Cornea Donation and Transplantation Access in Canada" held in February 2020, survey questions were posed to eye banks, transplanting ophthalmologists and organ donation organizations across Canada to learn more about demand, wait times, and access to tissue for transplant. The survey response rate was one hundred percent (100%) for eye banks and organ donation organizations while 64 percent (64%) of transplant ophthalmologists provided feedback. A number of opportunities for improvement were identified including: demand forecasting; infrastructure and strategies to align supply with demand; data collection and benchmarking of wait times for assessment and transplant to support consistency, equitability and transparency in access; and national collaboration in the development of a data strategy to accurately measure demand and access to cornea transplants in a consistent manner across all provinces to facilitate equity in access nationally.