Global Disparities in Access to Vaccine Clinical Trials: A Review of the Literature.

Vaccines are an effective tool to reduce the disease burden from infectious diseases on a population, infrastructural, and individual level. Before vaccines can be administered to populations at large, they must go through rigorous testing in the form of clinical trials. While vaccine trials can be used to assess the efficacy of interventions on a local populace as well as target local endemic diseases, most clinical trials are sponsored and conducted by companies in high-income countries (HICs). This can lead to vaccines that are not optimized for low- and middle-income countries (LMICs) and that often neglect to address diseases specific to the local population. This narrative review aims to explore the factors leading to discrepancies in the execution of and access to vaccine trials between HICs and LMICs, thus guiding future efforts in confronting them. This review was written using the literature sourced from the PubMed database and supplemented with articles from Google Scholar along with grey literature. Several themes are highlighted including poorly defined regulatory and ethical guidelines, staff shortages, lack of research infrastructure, and logistical barriers. We discuss how these challenges have affected vaccine development in various capacities through case examples of SARS-CoV-2, poliovirus, and malaria. Many challenges remain in equitable vaccine clinical trial development and implementation. Facilitating the implementation of locally sponsored vaccine clinical trials in LMICs may be one avenue to address these challenges. In doing so, LMICs can become active stakeholders in the health of their citizens by addressing endemic diseases, tailoring vaccine specifications based on local needs, and implementing wide-scale vaccine access and delivery.

Suppression of Neovascularization by Topical and Subconjunctival Bevacizumab After High-Risk Corneal Transplantation.

Purpose: To assess the effectiveness of topical and subconjunctival bevacizumab in suppressing vascularization in graft and host bed after high-risk corneal transplantation. Design: Secondary analysis of prospective, randomized, double-blind, placebo-controlled multicentric clinical trial. Participants: The study includes patients aged > 18 years who underwent high-risk penetrating keratoplasty, which was defined as corneal vascularization in ≥ 1 quadrants of the corneal graft and host bed, excluding the limbus. Methods: Patients were randomized to treatment and control groups. The patients in the treatment group received subconjunctival injection of bevacizumab (2.5 mg/0.1 ml) on the day of the procedure, followed by topical bevacizumab (10 mg/ml) 4 times per day for 4 weeks. The patients in control group received injection of vehicle (0.9% sodium chloride) on the day of procedure, followed by topical vehicle (carboxymethylcellulose sodium 1%) 4 times a day for 4 weeks. Main Outcome Measures: Vessel and invasion area of vessels in the corneal graft and host beds. Results: This study included 56 eyes of 56 patients who underwent high-risk corneal transplantation, with equal numbers in the bevacizumab and vehicle (control) treatment groups. The mean age of patients who received bevacizumab was 61.2 ± 15.9 years, and the mean age of those treated with vehicle was 60.0 ± 16.1 years. The vessel area at baseline was comparable in the bevacizumab (16.72% ± 3.19%) and control groups (15.48% ± 3.12%; P = 0.72). Similarly, the invasion areas were also similar in the treatment (35.60% ± 2.47%) and control (34.23% ± 2.64%; P = 0.9) groups at baseline. The reduction in vessel area was significantly higher in the bevacizumab-treated group (83.7%) over a period of 52 weeks compared with the control group (61.5%; P < 0.0001). In the bevacizumab-treated group, invasion area was reduced by 75.8% as compared with 46.5% in the control group. The vessel area was similar at 52 weeks postprocedure in cases of first (3.54% ± 1.21%) and repeat (3.80% ± 0.40%) corneal transplantation in patients who received bevacizumab treatment. In the vehicle-treated patients, the vessel area was significantly higher in repeat (9.76% ± 0.32%) compared with first (8.06% ± 1.02%; P < 0.0001) penetrating keratoplasty. In the bevacizumab treatment group, invasion areas at week 52 were comparable in first (11.70% ± 3.38%) and repeat (11.64% ± 1.74%) procedures, whereas invasion area was significantly higher in repeat (27.87% ± 2.57%) as compared with first (24.11% ± 2.17%) penetrating keratoplasty in vehicle-treated patients. Conclusions: In patients undergoing vascularized high-risk corneal transplantation, bevacizumab is efficacious in reducing vascularization of corneal graft and host bed, thereby reducing the risk of corneal graft rejection in vascularized host beds. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Ocular lichen planus as a cause of recurrent restrictive strabismus.

We report the case of an 80-year-old man with restrictive strabismus in lateral gaze following multiple oculoplastic procedures for idiopathic epiphora. Despite excellent initial response to nasal conjunctival recession with lysis of adhesions and a miminal recession of the medial rectus muscle, the patient suffered recurrence of diplopia associated with limitation of abduction due to aggressive, deep, subconjunctival scarring. Given the history of oral lichen planus (LP), the patient was diagnosed with ocular involvement of LP. He underwent a second conjunctival recession, this time accompanied by an intensive LP treatment regimen. Nine months after surgery, he remained diplopia free and orthophoric in primary gaze. Surgeons treating restrictive strabismus in patients with LP should consider implementing systemic and topical immunosuppressive treatment simultaneously with surgical management.

Long-term outcomes of glued (sutureless) amniotic membrane transplantation in acute Stevens-Johnson syndrome/toxic epidermal necrolysis: a comparative study.

PURPOSE: To compare the effectiveness and efficiency of a glued (sutureless) technique for amniotic membrane transplantation (AMT) with a traditional sutured one in the setting of acute Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN). METHODS: This retrospective cohort study evaluated all patients diagnosed with SJS/TEN between 2008 and 2020 within our hospital network who received AMT in the acute phase according to our protocol and had at least one ophthalmic follow-up in the chronic phase. Primary outcomes included best-corrected visual acuity (BCVA) at the most recent visit, presence of a severe ocular complication (SOC) via predefined criteria, time to procedure and duration of procedure. Random effects model analysis was used to evaluate the impact of potential covariates on outcome measures. RESULTS: A total of 23 patients (45 eyes) were included: 14 patients (27 eyes) in the AMT suture group and 9 patients (18 eyes) in the AMT glue group. There was no difference between the two groups in BCVA at the most recent visit (p=0.5112) or development of a SOC (p=1.000). The glue method was shorter in duration than the suture method (p<0.001). Random effects model additionally indicated that there was no difference in BCVA at most recent follow-up between patients who had received glued versus sutured AMT (p=0.1460). CONCLUSIONS: Our glued technique for AMT is as effective as our sutured technique in stabilising the ocular surface and mitigating chronic ocular complications in SJS/TEN. The glued technique is also shorter in duration and performed more expediently than the sutured technique.

New Frontiers in Acanthamoeba Keratitis Diagnosis and Management.

Acanthamoeba Keratitis (AK) is a severe corneal infection caused by the Acanthamoeba species of protozoa, potentially leading to permanent vision loss. AK requires prompt diagnosis and treatment to mitigate vision impairment. Diagnosing AK is challenging due to overlapping symptoms with other corneal infections, and treatment is made complicated by the organism's dual forms and increasing virulence, and delayed diagnosis. In this review, new approaches in AK diagnostics and treatment within the last 5 years are discussed. The English-language literature on PubMed was reviewed using the search terms "Acanthamoeba keratitis" and "diagnosis" or "treatment" and focused on studies published between 2018 and 2023. Two hundred sixty-five publications were initially identified, of which eighty-seven met inclusion and exclusion criteria. This review highlights the findings of these studies. Notably, advances in PCR-based diagnostics may be clinically implemented in the near future, while antibody-based and machine-learning approaches hold promise for the future. Single-drug topical therapy (0.08% PHMB) may improve drug access and efficacy, while oral medication (i.e., miltefosine) may offer a treatment option for patients with recalcitrant disease.

Updates in SJS/TEN: collaboration, innovation, and community.

Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis (SJS/TEN) is a predominantly drug-induced disease, with a mortality rate of 15-20%, that engages the expertise of multiple disciplines: dermatology, allergy, immunology, clinical pharmacology, burn surgery, ophthalmology, urogynecology, and psychiatry. SJS/TEN has an incidence of 1-5/million persons per year in the United States, with even higher rates globally. One of the challenges of SJS/TEN has been developing the research infrastructure and coordination to answer questions capable of transforming clinical care and leading to improved patient outcomes. SJS/TEN 2021, the third research meeting of its kind, was held as a virtual meeting on August 28-29, 2021. The meeting brought together 428 international scientists, in addition to a community of 140 SJS/TEN survivors and family members. The goal of the meeting was to brainstorm strategies to support the continued growth of an international SJS/TEN research network, bridging science and the community. The community workshop section of the meeting focused on eight primary themes: mental health, eye care, SJS/TEN in children, non-drug induced SJS/TEN, long-term health complications, new advances in mechanisms and basic science, managing long-term scarring, considerations for skin of color, and COVID-19 vaccines. The meeting featured several important updates and identified areas of unmet research and clinical need that will be highlighted in this white paper.

Severe ocular complications of SJS/TEN and associations among pre-onset, acute, and chronic factors: a report from the international ophthalmology collaborative group.

We formed an international research collaboration that included Japan, South Korea, Brazil, Thailand, Taiwan, the UK, and the US (682 patients from 13 hospitals between 2005 and 2020), to better evaluate the role of race, ethnicity, and other risk factors in the pathophysiology of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). Ophthalmologists often see SJS/TEN patients with severe ocular complications (SOC; frequency 50% SJS/TEN patients) when the patients are referred to them in the chronic stage after the acute stage has passed. Global data were collected using a Clinical Report Form, capturing pre-onset factors, as well as acute and chronic ocular findings. Key conclusions of this retrospective observational cohort study were as follows: (1) Ingestion of cold medications [acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs)] was significantly and positively correlated with trichiasis, symblepharon, and/or conjunctivalization of the cornea in the chronic stage; (2) common cold symptoms prior to onset of SJS/TEN were significantly and positively correlated with acute conjunctivitis and ocular surface erosions in the acute stage and with trichiasis and symblepharon and/or conjunctivalization of the cornea in the chronic stage; (3) patients with SJS/TEN who presented with SOC tended to be female; (4) patients less than 30 years of age are more likely to develop SOC in the acute and chronic stages of SJS/TEN; (5) patients with acute severe conjunctivitis with ocular surface erosion and pseudomembrane formation in the acute stage are more likely to develop ocular sequelae in the chronic stage; and (6) onychopathy in the acute stage was positively correlated with ocular sequelae in the chronic stage. Our findings show that the ingestion of cold medications, common cold symptoms prior to the onset of SJS/TEN, and a young age might strongly contribute to developing the SOC of SJS/TEN.

Ocular involvement in allergic drug reactions.

PURPOSE OF REVIEW: Many systemic medications have been observed to cause ocular toxicity. A subset of these reactions is thought to involve immunomodulation or a hypersensitivity reaction. As new medications are developed, ocular adverse effects are becoming increasingly prevalent. Herein we review immune-mediated drug reactions affecting they eye with special attention to the hypersensitivity mechanisms leading to ocular toxicity. RECENT FINDINGS: Recent work has focused on mechanisms and risk of immune-mediated ocular adverse drug reactions including genetic susceptibility and loss of ocular immune privilege. SUMMARY: Given the consequences of immune-mediated ocular adverse drug reactions, clinicians must be aware of these to facilitate early recognition and management. The prompt involvement of an ophthalmologist for diagnosis and management is often essential to preserve vision and avoid long-term morbidity.

Corneal Adverse Events Associated with SARS-CoV-2/COVID-19 Vaccination: A Systematic Review.

Vaccines against coronavirus disease 2019 (COVID-19) have played an important global role in reducing morbidity and mortality from COVID-19 infection. While the benefits of vaccination greatly outweigh the risks, adverse events do occur. Non-ocular adverse effects of the vaccines have been well-documented, but descriptions of ophthalmic effects remain limited. This systematic review aims to provide an overview of reported cases of corneal adverse events after receiving vaccination against COVID-19 and to compile existing clinical data to bring attention to these phenomena. Our review discusses corneal graft rejection, including proposed mechanisms, herpetic keratitis, and other reported corneal complications. Ophthalmologists and primary care physicians should be aware of such possible associations.

Relationship between Atopic Disease and Acute Ocular and Systemic Outcomes in Patients with Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis.

OBJECTIVE: To describe the relationship between history of atopic disease on systemic and ocular manifestations of Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis (SJS/TEN). METHODS: Retrospective chart review of patients with SJS/TEN patients. Those with and without prior atopic diagnosis were compared. RESULTS: In total, 200 patients with SJS/TEN were identified. A total of 23 patients also had an atopic diagnosis. Four, 10, and 18 had atopic dermatitis, allergic rhinitis, and asthma respectively. Acute ocular severity was significantly worse in the atopic cohort. No significant differences in overall systemic severity of SJS or mortality were found between the atopic and non-atopic cohorts. Compared to our hospital system's general population, prevalence of an atopic diagnosis was significantly higher in those with SJS/TEN. CONCLUSION: Patients with a history of an atopic diagnosis appear to have more significant acute ocular involvement during their SJS/TEN hospitalization. Atopic conditions appear to occur more frequently in the SJS/TEN population compared to the general population.

Disparities in Access to Corneal Tissue in the Developing World.

Corneal disease is a leading cause of blindness worldwide. For most blinding corneal conditions, keratoplasty is the only way of restoring sight. Unfortunately, access to corneal transplantation is widely variable, most notably due to the lack of suitable donor material. There exists significant disparity between the developed and developing world when it comes to access to cornea tissue, with supply often inversely proportional to burden of disease. The purpose of this review is to identify the current disparities in supply and demand of corneal donor tissue, understand how to access corneal tissue, and propose solutions that promote equitable care for patients with severe corneal disease.

Ocular involvement in Mycoplasma induced rash and mucositis: A systematic review of the literature.

Mycoplasma pneumoniae induced rash and mucositis (MIRM) is a relatively newly identified clinical entity which is characterized by mucocutaneous manifestations in the setting of Mycoplasma infection. Though a clinically distinct disease, MIRM exists on a diagnostic continuum with entities including erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis, and the recently described reactive infectious mucocutaneous eruption (RIME). In this systematic review, we discuss published findings on the epidemiology, clinical manifestations, diagnosis, and management of MIRM, with an emphasis on ocular disease. Lastly, we discuss some of the most recent developments and challenges in characterizing MIRM with respect to the related diagnosis of RIME.

Incidence and risk factors for glaucoma development and progression after corneal transplantation.

OBJECTIVE: To assess the cumulative incidence and risk factors for glaucoma development and progression within 1-2 years following corneal transplant surgery. DESIGN: Retrospective cohort study. METHODS: Patients undergoing penetrating keratoplasty (PK), deep anterior lamellar keratoplasty (DALK), Descemet stripping endothelial keratoplasty (DSEK), Descemet membrane endothelial keratoplasty (DMEK), Boston keratoprosthesis type I (KPro) implantation, or endothelial keratoplasty (DSEK or DMEK) under previous PK (EK under previous PK) at one academic institution with at least 1 year of follow-up were included. Primary outcome measures were cumulative incidence of glaucoma development and progression after corneal transplant, in patients without and with preoperative glaucoma, respectively. Risk factors for glaucoma development and progression were also assessed. RESULTS: Four hundred and thirty-one eyes of 431 patients undergoing PK (113), DALK (17), DSEK (71), DMEK (168), KPro (35) and EK under previous PK (27) with a mean follow-up of 22.9 months were analyzed. The 1-year cumulative incidence for glaucoma development and progression was 28.0% and 17.8% in patients without and with preoperative glaucoma, respectively. In a Cox proportional hazards analysis, DSEK surgery, KPro implantation, average intraocular pressure (IOP) through follow-up and postoperative IOP spikes of ≥30 mmHg were each independently associated with glaucoma development or progression (p < 0.04 for all). CONCLUSIONS: A significant proportion of patients developed glaucoma or exhibited glaucoma progression within 1 year after corneal transplantation. Patient selection for DSEK may partly explain the higher risk for glaucoma in these patients. Postoperative IOP spikes should be minimized and may indicate the need for co-management with a glaucoma specialist.

Sulfated motifs in heparan sulfate inhibit Streptococcus pneumoniae adhesion onto fibronectin and attenuate corneal infection.

A large number of bacterial pathogens bind to host extracellular matrix (ECM) components. For example, many Gram-negative and Gram-positive pathogens express binding proteins for fibronectin (FN) on their cell surface. Mutagenesis studies of bacterial FN-binding proteins have demonstrated their importance in pathogenesis in preclinical animal models. However, means to draw on these findings to design therapeutic approaches that specifically target FN-bacteria interactions have not been successful because bacterial pathogens can elaborate several FN-binding proteins and also because FN is an essential protein and likely a nondruggable target. Here we report that select heparan compounds potently inhibit Streptococcus pneumoniae infection of injured corneas in mice. Using intact heparan sulfate (HS) and heparin (HP), heparinase-digested fragments of HS, HP oligosaccharides, and chemically or chemoenzymatically modified heparan compounds, we found that inhibition of S. pneumoniae corneal infection by heparan compounds is not mediated by simple charge effects but by a selective sulfate group. Removal of 2-O-sulfates significantly inhibited the ability of HP to inhibit S. pneumoniae corneal infection, whereas the addition of 2-O-sulfates to heparosan (H) significantly increased H's ability to inhibit bacterial corneal infection. Proximity ligation assays indicated that S. pneumoniae attaches directly to FN fibrils in the corneal epithelial ECM and that HS and HP specifically inhibit this binding interaction in a 2-O-sulfate-dependent manner. These data suggest that heparan compounds containing 2-O-sulfate groups protect against S. pneumoniae corneal infection by inhibiting bacterial attachment to FN fibrils in the subepithelial ECM of injured corneas. Moreover, 2-O-sulfated heparan compounds significantly inhibited corneal infection in immunocompromised hosts, by a clinical keratitis isolate of S. pneumoniae, and also when topically administered in a therapeutic manner. These findings suggest that the administration of nonanticoagulant 2-O-sulfated heparan compounds may represent a plausible approach to the treatment of S. pneumoniae keratitis.

An alternative model for assessing mortality risk in Stevens Johnson syndrome/toxic epidermal necrolysis using a random forests classifier: A pilot study.

Introduction: Mortality risk prediction is an important part of the clinical assessment in the Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN) patient. The SCORTEN and ABCD-10 scoring systems have been used as predictive clinical tools for assessing this risk. However, some of the metrics required in calculating these scores, such as the total body surface area (TBSA) involvement, are difficult to calculate. In addition, TBSA involvement is calculated in a variety of ways and is observer dependent and subjective. The goal of this study was to develop an alternative method to predict mortality in patients with SJS/TEN. Methods: Data was split into training and test datasets and preprocessed. Models were trained using five-fold cross validation. Out of several possible candidates, a random forests model was evaluated as being the most robust in predictive power for this dataset. Upon feature selection, a final random forests model was developed which was used for comparison against SCORTEN. Results: The differences in both accuracy (p = 0.324) and area under the receiver operating characteristic curve (AUROC) (p = 0.318) between the final random forests model and the SCORTEN and ABCD-10 models were not statistically significant. As such, this alternative method performs similarly to SCORTEN while only requiring simple laboratory tests from the day of admission. Discussion: This new alternative can make the mortality prediction process more efficient, along with providing a seamless implementation of the patient laboratory tests directly into the model from existing electronic health record (EHR) systems. Once the model was developed, a web application was built to deploy the model which integrates with the Epic EHR system on the Fast Healthcare Interoperability Resources (FHIR) Application Programming Interface (API); this only requires the patient medical record number and a date of the lab tests as parameters. This model ultimately allows clinicians to calculate patient mortality risk with only a few clicks. Further studies are needed for validation of this tool.

Visual function and quality of life in patients with Stevens-Johnson syndrome who received acute protocol-based ocular care.

Purpose: To report visual function and quality of life (VF/QOL) using the National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) and the ocular surface disease index (OSDI) in patients in the chronic phase of Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN). Methods: The NEI-VFQ-25 questionnaire was administered to 15 patients who received protocol-based care in the form of topical medications with or without amniotic membrane transplantation (AMT) for acute SJS/TEN. The scores obtained were compared with scores from a healthy population. The associations between the NEI-VFQ-25 and dry eye symptoms as measured by OSDI questionnaire were also studied. Results: Patients were surveyed at a mean of 4.47 ± 2.22 years after acute SJS/TEN. Eleven patients received AMT in the acute phase. The median best corrected visual acuity at the time of administration of the questionnaire was 20/20. The mean composite NEI-VFQ-25 score was 86.48 ± 12. Patients who received protocol-based treatment in the acute phase of SJS/TEN had comparable NEI-VFQ-25 scores with healthy subjects on all subscales except ocular pain (p = 0.027) and mental health (p = 0.014), which were significantly reduced. The NEI-VFQ-25 composite scores significantly correlated with OSDI (R = -0.75, p = 0.001). Conclusion: A protocol-based management strategy composed of early ophthalmic evaluation, grading based on severity, the use of topical corticosteroids and AMT in the acute phase of SJS/TEN in patients with ocular complications helped preserve the VF/QOL. This study highlights the impact of appropriate management of the ocular complications in the acute phase of SJS/TEN.

Topical cenegermin 0.002% for pediatric neurotrophic keratopathy.

PURPOSE: To evaluate the efficacy and safety of cenegermin 0.002% ophthalmic drops in the management of pediatric neurotrophic keratopathy (NK). METHODS: Retrospective chart review of children under the age of 18 years diagnosed with NK at Boston Children's Hospital/Massachusetts Eye and Ear Infirmary and treated with topical cenegermin 0.002% ophthalmic solution between June 2018 and June 2021 was performed. Data collection included etiology of NK, age at time of initiation of topical cenegermin, laterality, ethnicity, gender, history of previous ocular therapy, pre- and post-therapy best corrected visual acuity, pre- and post-therapy cornea examination, any adverse events from topical cenegermin, associated ocular conditions, and history of ocular surgeries. RESULTS: The current study includes four eyes of four pediatric patients with a mean age of 4.5 ± 2.0 years at the time of initiation of topical cenegermin therapy. The mean time from NK diagnosis until start of topical cenegermin drops was 5.2 ± 4.3 months and mean follow-up time was 15 ± 9.6 months. In all four patients, marked improvement in epitheliopathy was demonstrated after completion of therapy. Best corrected visual acuity was measurable in 3 eyes of 3 patients, and it improved from a mean of 0.07 ± 0.01 to a mean of 0.29 ± 0.26 (P = 0.3). No adverse events related to cenegermin therapy were noted. CONCLUSION: Topical cenegermin was effective in improving corneal healing for pediatric NK.