Pharmaceutical Emulsions: A Viable Approach for Ocular Drug Delivery

Ocular disorders can lead to serious sight impairment and irreversible blindness. Generally simple topical and systemic treatments are recommended for treating these vision-threatening illnesses. The distinctive architecture of the eye complicates ocular drug delivery. The ophthalmic emulsion formulations have been found to increase bioavailability in the eye by prolonging residence time and improving permeability through the cornea. Therefore, this study highlights ophthalmic emulsions meant for both the anterior and posterior parts of the eye while examining a wide range of ocular disorders that affect individuals globally. This review presents, in brief, recent emulsion-based patented innovations, clinical trials, and marketed emulsion formulations for ocular drug delivery, which are strengthening development of the new ophthalmic drug products for managing different ocular diseases and disorders.

Understanding Acanthamoeba Keratitis: An In-Depth Review of a Sight-Threatening Eye Infection

Acanthamoeba keratitis (AK) is a rare but potentially sight-threatening corneal infection caused by the Acanthamoeba parasite. This microorganism is found ubiquitously in the environment, often in freshwater, soil, and other sources of moisture. Despite its low incidence, AK presents significant challenges due to delayed diagnosis and the complex nature of therapeutic management. Early recognition is crucial to prevent severe ocular complications, including corneal ulceration and vision loss. Diagnostic modalities and treatment strategies may vary greatly depending on the clinical manifestation and the available tools. With the growing reported cases of Acanthamoeba keratitis, it is essential for the ophthalmic community to thoroughly understand this condition for its effective management and improved outcomes. This review provides a comprehensive overview of AK, encompassing its epidemiology, risk factors, pathophysiology, clinical manifestations, diagnosis, and treatment.

Xanthogranulomatous keratitis in a mixed-breed dog

OBJECTIVE

To evaluate the clinical and histopathological features of a case of xanthogranulomatous keratitis in a mixed-breed dog.

ANIMAL

Mixed-breed dog.

CLINICAL PRESENTATION, PROGRESSION, AND PROCEDURES

An 11-year-old spayed female mixed-breed dog was presented for mild blepharospasm, corneal cloudiness, and increasing conjunctival hyperemia OD. Ophthalmic examination revealed multifocal pink and cream-colored consolidated corneal infiltrative lesions and generalized neovascularization with suspected diagnosis of stromal abscessation. There was no improvement after 1 month of medical management, so a keratectomy was performed, and corneal tissue was sent for histopathological evaluation.

TREATMENT AND OUTCOME

The nonulcerative keratitis was refractive to medical management including topical and systemic antibiotics, topical antifungal, and systemic anti-inflammatory, so keratectomy was performed. Histopathologic diagnosis of xanthogranulomatous keratitis was made 1 week postoperatively. The patient was prescribed 0.05% difluprednate ophthalmic emulsion and 0.2% tacrolimus ophthalmic ointment (initially q 8 h, OD). The difluprednate was tapered and discontinued after 2 months, but the tacrolimus was continued (q 12 h, OD). No lesion recurrence had been documented 1 year postoperatively.

CLINICAL RELEVANCE

There has been little published on canine xanthogranulomas, especially in veterinary ophthalmology. Ocular xanthogranulomas have been reportedly found intraocularly and at the ocular surface. Histologically, they are characterized by well-delineated nodules that contain histiocytes and abundant lipid-laden macrophages. The treatment in this clinical case was surgical excision followed with topical immunosuppression/anti-inflammatory therapy with no recurrence 1 year postoperatively. Xanthogranulomatous keratitis should be an added differential diagnosis when nonulcerative keratitis is found on examination, specifically with consolidated, corneal infiltrate and minimal pain.

Corneal Ulcer due to Monkeypox Infection

PURPOSE

To report a rare case of keratitis due to monkeypox infection.

METHODS

A 45-year-old male presented with an epithelial corneal ulcer 20 days following initial diagnosis of monkeypox from genital and perioral lesions. PCR analysis of the epithelium confirmed the presence of human monkeypox virus.

RESULTS

The patient was hospitalized, and ganciclovir gel, as well as povidone iodine 0.6% and moxifloxacin eyedrops were prescribed. Oral tecovirimat 600 mg was administered during 14 days. A therapeutic contact lens was used. Twenty days after the initial diagnosis of keratitis, the corneal defect closed leaving a faint subepithelial haze, and visual acuity was 0.8.

CONCLUSIONS

This is an uncommon case report of epithelial keratitis due to human monkeypox. PCR positivity for monkeypox in the corneal epithelium confirmed the presence of viral material in the cornea.

Antimicrobial resistance in ocular infection: A review

Antimicrobial resistance (AMR) is a global public health threat with significant impact on treatment outcomes. The World Health Organization's Global Action Plan on AMR recommended strengthening the evidence base through surveillance programs and research. Comprehensive, timely data on AMR for organisms isolated from ocular infections are needed to guide treatment decisions and inform researchers and microbiologists of emerging trends. This article aims to provide an update on the development of AMR in ocular organisms, AMR in bacterial ocular infections and on AMR stewardship programs globally. The most common ocular pathogens are Pseudomonas aeruginosa, Staphylococcus spp., Streptococcus pneumoniae, and Haemophilus influenzae in ocular infections. A variety of studies and a few surveillance programs worldwide have reported on AMR in these infections over time. Fluoroquinolone resistance has increased particularly in Asia and North America. For conjunctivitis, the ARMOR cumulative study in the USA reported a slight decrease in resistance to ciprofloxacin. For keratitis, resistance to methicillin has remained stable for S. aureus and CoNS, while resistance to ciprofloxacin has decreased for MRSA globally. Methicillin-resistance and multidrug resistance are also emerging, requiring ongoing monitoring. Antimicrobial stewardship (AMS) programmes have a critical role in reducing the threat of AMR and improving treatment outcomes. To be successful AMS must be informed by up-to-date AMR surveillance data. As a profession it is timely for ophthalmology to act to prevent AMR leading to greater visual loss through supporting surveillance programmes and establishing AMS.

Mpox-Related Ophthalmic Disease: A Retrospective Observational Study in a Single Center in Mexico

Mpox-related ophthalmic disease has been reported as infrequent. We retrospectively describe the ocular manifestations present in 11 of 100 patients with confirmed mpox; 9 were people with HIV. We suggest that an ophthalmological evaluation should be performed in all patients with ocular symptoms or moderate and severe mpox disease.

Keratic Precipitates: An Overlooked Sign of Microsporidial Stromal Keratitis?

PURPOSE

To elucidate a distinctive clinical feature in cases of microsporidial stromal keratitis (MSK).

METHOD

A retrospective observational study of cases with a histopathological and/or microbiological diagnosis of MSK on corneal biopsy or host corneal button between 2016 and 2022 was conducted.

RESULTS

Eighteen cases with a confirmed histopathological and/or microbiological diagnosis of MSK were detected. Careful review of slit-lamp photographs revealed the presence of pigmented keratic precipitates (KPs) beyond the area of stromal keratitis in five out of eighteen cases (27.7%).

CONCLUSION

The presence of pigmented KPs beyond the area of lesion can alert the clinician to keep microsporidia as a differential cause for stromal keratitis. Management can be tailored accordingly for a better outcome.

New-onset keratitis associated with epidermal growth factor receptor-based targeted therapies in Han Chinese patients with lung cancer: A multi-center cohort study

PURPOSE

To determine the risk and incidence of keratitis following treatment with epidermal growth factor receptor inhibitors (EGFRi) and subtypes of EGFRi-associated keratitis.

METHODS

This multi-center cohort study included EGFRi-treated patients and non-users with lung cancer between 2010 and 2023. EGFRi included first-generation agent gefitinib and erlotinib, second-generation agent afatinib, and third-generation agent osimertinib. The primary outcome was new-onset keratitis. Cox proportional hazard models with multivariable adjustment were applied to determine the effect of EGFRi on keratitis over time. Subgroup analyses were conducted, stratified by agents of EGFRi. Sub-outcome analyses were performed to identify the subtypes of EGFRi-associated keratitis.

RESULTS

A total of 1549 EGFRi-treated patients and 6146 non-users were included. 38 (2.5%) EGFRi-treated patients developed keratitis. The incidence of keratitis in EGFRi-treated patients was significantly higher than that in controls (incidence rate, IR, per 1000 person-years = 14.7 vs 4.49, p < 0.0001). EGFRi-treated patients presented with an increased risk for keratitis (adjusted hazard ratio, aHR = 3.14, 95% CI = 1.85-5.35, p < 0.001). Erlotinib (aHR = 2.64, 95% CI = 1.35-5.15, p = 0.004), afatinib (aHR = 4.42, 95% CI = 2.17-9.02, p < 0.001), and osimertinib (aHR = 4.67, 95% CI = 1.60-13.64, p = 0.005), but not gefitinib (aHR = 2.30, 95% CI = 0.96-5.55, p = 0.063), significantly contributed to the risk of keratitis. Subtypes of EGFRi-associated keratitis included corneal ulcer (IR = 2.31 vs 0.166, p < 0.0001) and keratoconjunctivitis (IR = 9.27 vs 2.91, p < 0.0001). None of the EGFRi-treated patients developed perforated corneal ulcer, interstitial and deep keratitis, or corneal neovascularization.

CONCLUSION

Treatment with EGFRi was associated with an increased risk of keratitis. Ocular toxicity of EGFRi was highest for third-generation agents, followed by second-generation agents, and then first-generation agents.

Breaking-Down Barriers: Proposal of Using Cellulose Biosynthesis Inhibitors and Cellulase Enzyme as a Novel Treatment Modality for Vision Threatening Pythium Insidiosum Keratitis

Pythium insidiosum, an Oomycete, causes severe keratitis that endangers vision. Its clinical, morphological, and microbiological characteristics are often indistinguishable from those of fungal keratitis, earning it the moniker "parafungus". Distinctive clinical hallmarks that set it apart from other forms of keratitis include radial keratoneuritis, tentacles, marginal infiltration, and a propensity for rapid limbal spread. The therapeutic approach to Pythium keratitis (PK) has long been a subject of debate, and topical and systemic antifungals and antibacterials have been tried with limited success. Approximately 80% of these eyes undergo therapeutic keratoplasty to salvage the eye. Hence, there is a need to innovate for alternative and better medical therapy to safeguard these eyes. The resistance of Pythium to standard antifungal treatments can be attributed to the absence of ergosterol in its cell wall. Cell walls of plants and algae have cellulose as an essential constituent. Cellulose imparts strength and structure and acts as the "skeleton" of the plant. Fungal and animal cell walls typically lack cellulose. The cellular architecture of Pythium shares a similarity with plant and algal cells through the incorporation of cellulose within its cell wall structure. Inhibitors targeting cellulose biosynthesis (CBI), such as Indaziflam, Isoxaben, and Quinoxyphen, serve as critical tools for elucidating the pathways of cellulose synthesis. Furthermore, the enzymatic action of cellulase is instrumental for the extraction of proteins and DNA. To circumvent this issue, we hypothesize that CBI's and cellulase enzymes can act on the Pythium cell wall and may effectively treat PK. The available literature supporting the hypothesis and proof of concept has also been discussed. We have also discussed these drugs' molecular mechanism of action on the Pythium cell wall. We also aim to propose how these drugs can be procured and used as a potential medical management option for this devastating entity.

Characterization of the resistome and predominant genetic lineages of Gram-positive bacteria causing keratitis

Bacterial keratitis is a vision-threatening infection mainly caused by Gram-positive bacteria (GPB). Antimicrobial therapy is commonly empirical using broad-spectrum agents with efficacy increasingly compromised by the emergence of antimicrobial resistance. We used a combination of phenotypic tests and genome sequencing to identify the predominant lineages of GPB causing keratitis and to characterize their antimicrobial resistance patterns. A total of 161 isolates, including Staphylococcus aureus (n = 86), coagulase-negative staphylococci (CoNS; n = 34), Streptococcus spp. (n = 34), and Enterococcus faecalis (n = 7), were included. The population of S. aureus isolates consisted mainly of clonal complex 5 (CC5) (30.2%). Similarly, the population of Staphylococcus epidermidis was homogenous with most of them belonging to CC2 (78.3%). Conversely, the genetic population of Streptococcus pneumoniae was highly diverse. Resistance to first-line antibiotics was common among staphylococci, especially among CC5 S. aureus. Methicillin-resistant S. aureus was commonly resistant to fluoroquinolones and azithromycin (78.6%) and tobramycin (57%). One-third of the CoNS were resistant to fluoroquinolones and 53% to azithromycin. Macrolide resistance was commonly caused by erm genes in S. aureus, mphC and msrA in CoNS, and mefA and msr(D) in streptococci. Aminoglycoside resistance in staphylococci was mainly associated with genes commonly found in mobile genetic elements and that encode for nucleotidyltransferases like ant(4')-Ib and ant(9)-Ia. Fluroquinolone-resistant staphylococci carried from 1 to 4 quinolone resistance-determining region mutations, mainly in the gyrA and parC genes. We found that GPB causing keratitis are associated with strains commonly resistant to first-line topical therapies, especially staphylococcal isolates that are frequently multidrug-resistant and associated with major hospital-adapted epidemic lineages.

Pirfenidone: A Promising Drug in Ocular Therapeutics

Pirfenidone, initially indicated for lung fibrosis, has gone beyond its original purpose, and shown promise in eye care. This detailed review tracks its evolution from lung treatment to aiding eye healing as evidenced by published literature. Pirfenidone's multifaceted attributes extend to mitigating corneal fibrosis, inflammation, and trauma. Through rigorous investigations, its efficacy emerges in diabetic retinopathy, macular degeneration, and postoperative glaucoma interventions. As an unheralded protagonist, pirfenidone reshapes ocular care paradigms, inviting renewed research opportunities.

Pseudomonas Keratitis: From Diagnosis to Successful Deep Anterior Lamellar Keratoplasty

Pseudomonas keratitis is an aggressive form of bacterial keratitis that can have devastating consequences, such as corneal perforation, if not promptly identified and appropriately managed. The aim of this case report is to highlight key clinical features of Pseudomonas keratitis and evaluate the initial and long-term management options for this condition. We report a case of a 32-year-old female who presented with a large corneal abscess and hypopyon following contact lens wear. Corneal cultures confirmed Pseudomonas as the causative organism and she was treated with topical levofloxacin and gentamycin. Following sterilisation of the corneal ulcer, the patient was left with deep stromal scarring, peripheral corneal thinning as well as four-quadrant deep corneal vascularisation. She was listed for deep anterior lamellar keratoplasty surgery to clear her visual axis. We highlight some of the challenges that were faced both intra-operatively and post-operatively and how they were managed.

Genome sequence generated by hybrid Nanopore-Illumina assembly of an extensively drug-resistant Pseudomonas aeruginosa strain from a keratitis outbreak

Here, we report the genome sequence of an extensively drug-resistant Pseudomonas aeruginosa associated with a keratitis outbreak. This isolate was from the Center for Disease Control and Prevention and originates from a cornea. This sequence will facilitate studies of extensively drug resistant bacteria.

Epidemiology of and Genetic Factors Associated with Acanthamoeba Keratitis

Acanthamoeba keratitis (AK) is a severe, rare protozoal infection of the cornea. Acanthamoeba can survive in diverse habitats and at extreme temperatures. AK is mostly seen in contact lens wearers whose lenses have become contaminated or who have a history of water exposure, and in those without contact lens wear who have experienced recent eye trauma involving contaminated soil or water. Infection usually results in severe eye pain, photophobia, inflammation, and corneal epithelial defects. The pathophysiology of this infection is multifactorial, including the production of cytotoxic proteases by Acanthamoeba that degrades the corneal epithelial basement membrane and induces the death of ocular surface cells, resulting in degradation of the collagen-rich corneal stroma. AK can be prevented by avoiding risk factors, which includes avoiding water contact, such as swimming or showering in contact lenses, and wearing protective goggles when working on the land. AK is mostly treated with an antimicrobial therapy of biguanides alone or in combination with diaminidines, although the commercial availability of these medicines is variable. Other than anti-amoeba therapies, targeting host immune pathways in Acanthamoeba disease may lead to the development of vaccines or antibody therapeutics which could transform the management of AK.

Bedside assessment of ophthalmic manifestations in neurocritical care: A study in Southern India

PURPOSE

This study aimed to investigate the incidence of Ocular Surface Disorders (OSDs), including Dry Eye Disease, Chemosis, and Exposure Keratitis, among patients admitted to the Neurocritical Care Unit (NCC). Additionally, we sought to assess the correlation between these OSDs, the length of hospitalization at NCC, and the Glasgow Coma Score (GCS). The heightened risk of OSD development in the NCC environment, coupled with pre-existing neurological impairments, can lead to conditions like dry eye disease, chemosis, corneal abrasions, and infectious keratitis, ultimately resulting in corneal opacities and perforations that significantly impact visual acuity and overall quality of life.

METHODS

In this observational cross-sectional study, we examined the ocular health of all patients admitted to an NCC unit from February to May 2022. We assessed the presence of Conjunctivitis, chemosis, Keratitis, and Dry Eyes in relation to the duration of stay at NCC, GCS, lagophthalmos, adherence to the prescribed eye care protocol in NCC, and the use of mechanical ventilation. Our study comprised one hundred subjects over a four-month period, with a mean age of 51.92 ± 18.73 years (ranging from 17 to 89), including 70% males and 30% females (gender ratio of 2.33).

RESULTS

Our findings revealed that 26 eyes (13%) exhibited Conjunctival Hyperemia, 23 eyes (11.5%) displayed Chemosis, and severe dry eye was prevalent in 41 (20.5%) eyes. A statistically significant association was observed between GCS (p-value <0.001) and Keratitis (p-value 0.0035) with dry eyes (Chi-Square Test). Notably, the incidence of dry eyes was significantly higher among patients with a prolonged stay of ≥10 days (p-value 0.003).

CONCLUSIONS

Patients admitted to Neurocritical Care Units necessitate meticulous eye care and structured protocols to mitigate the risk of long-term ocular complications such as exposure keratitis. Given their heightened susceptibility to these conditions, proactive measures are imperative to ensure optimal ocular health among NCC patients.

In Vivo Confocal Microscopy Characterization of Candida parapsilosis Keratitis

ABSTRACT

The present clinical case concerns two patients with mycotic keratitis because of Candida parapsilosis in which corneal confocal microscopy presented a characteristic feature of this pathogen. Both described patients used a therapeutic contact lens and administered a therapy with steroid eye drops which are well known predisposing factors for the onset of corneal mycoses. This report can be useful for correctly identifying the pathologic condition and quickly directing the therapy.

Atopic Disease as a Risk Factor for Recurrent Herpetic Keratitis

Recurrent herpetic keratitis is a leading cause of blindness worldwide. In this population-based cross-sectional study, the medical records of Israeli adolescents and young adults who underwent systematic preconscription evaluation for mandatory military service were reviewed. The prevalence of atopic conjunctival disease was evaluated in cases with and without documented recurrent herpetic keratitis. The association was tested using uni- and multivariant analyses. Overall, 940,892 adolescents and young adults were included. The mean age was 17.57 ± 1.50 years (range 16-20 years), and 40.70% of participants were female. Recurrent herpetic keratitis was documented in 160 cases, with a prevalence of 0.017% in this age group. Compared to the general population, patients with recurrent herpetic keratitis were significantly more likely to be males (p = 0.003) with a concomitant diagnosis of atopic conjunctival disease (p < 0.0001). Patients with atopic conjunctival disease were 10.60-fold more likely to experience recurrent herpetic keratitis (95% confidence interval (CI): 6.76-16.64, p < 0.0001). Upon multivariate analysis, the results remained significant (p < 0.001). Cases of severe atopic conjunctival disease were more prone to recurrent HSV keratitis compared to mild cases (p < 0.001). These findings suggest that the timely appropriate treatment of atopic conjunctival disease may help reduce the frequency and severity of recurrent HSV keratitis and its complications.

Clinical Applications of Anterior Segment Optical Coherence Tomography: An Updated Review

Since its introduction, optical coherence tomography (OCT) has revolutionized the field of ophthalmology and has now become an indispensable, noninvasive tool in daily practice. Most ophthalmologists are familiar with its use in the assessment and monitoring of retinal and optic nerve diseases. However, it also has important applications in the assessment of anterior segment structures, including the cornea, conjunctiva, sclera, anterior chamber, and iris, and has the potential to transform the clinical examination of these structures. In this review, we aim to provide a comprehensive overview of the potential clinical utility of anterior segment OCT (AS-OCT) for a wide range of anterior segment pathologies, such as conjunctival neoplasia, pterygium, scleritis, keratoconus, corneal dystrophies, and infectious/noninfectious keratitis. In addition, the clinical applications of AS-OCT (including epithelial mapping) in preoperative planning and postoperative monitoring for corneal and refractive surgeries are discussed.

Osimertinib-induced Keratitis and Secondary Toxic Epidermal Necrotic Drug Eruption- A Case Report and Literature Review

BACKGROUND

Osimertinib is a third-generation Tyrosine Kinase inhibitor, mainly used in non-small cell lung cancer with EGFR mutation. Its efficacy and safety have been confirmed by clinical practice. Toxic epidermolysis necrotizing disease (TEN) is a severe drug eruption that is rare in clinics and has a high mortality rate. Toxic epidermal necrotic drug rash caused by Osimeritinib is even rarer.

OBJECTIVE

To investigate the rare side effects of Osimertinib through a case of toxic Epidermal necrosis.

CASE PRESENTATION

A 63-year-old female patient was diagnosed with lung adenocarcinoma with brain metastases, and genetic testing revealed an EGFR21 exon mutation. The disease progressed 24 days after the administration of gefitinib, then the patient switched to Osimertinib (80 mg QD) and, resulting in keratitis and secondary systemic toxic epidermolysis necrotizing disease (TEN). Finally, the patient died.

CONCLUSION

Although the clinical use of osimertinib is becoming widespread, the side effects may not be fully understood. Clinicians should pay more attention to the occurrence of the side reaction and deal with it in time.

Ocular infections associated with atypical mycobacteria: A review

Atypical mycobacteria or non-tuberculous mycobacteria (NTM) are a group of acid-fast bacteria that are pathogenic to different parts of the eye. The organisms can cause a spectrum of ocular infections including keratitis, scleritis, uveitis, endophthalmitis and orbital cellulitis. Trauma, whether surgical or nonsurgical, has the highest correlation with development of this infection. Common surgeries after which these infections have been reported include laser in situ keratomileusis (LASIK) and scleral buckle surgery. The organism is noted to form biofilms with sequestration of the microbe at different inaccessible locations leading to high virulence. Collection of infective ocular material (corneal scraping/necrotic scleral tissue/abscess material/vitreous aspirate, etc.) and laboratory identification of the organism through microbiologic testing are vital for confirming presence of the infection and initiating treatment. In cluster infections, tracing the source of infection in the hospital setting via testing of different in-house samples is equally important to prevent further occurrences. Although the incidence of these infections is low, their presence can cause prolonged disease that may often be resistant to medical therapy alone. In this review, we describe the various types of NTM-ocular infections, their clinical presentation, laboratory diagnosis, management, and outcomes.

Bilateral keratitis associated with afatinib therapy

This case discussed a significant ocular side effect, bilateral keratitis, which could be induced by afatinib, an irreversible epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI). We explored the disease progression of a 52-year-old, stage IV nasopharyngeal carcinoma male patient, who was under afatinib treatment and had experienced progressive bilateral eye dryness and tenderness on increasing afatinib from 40 mg every other day to 40 mg daily. Clinical examination noted bilateral visual acuity reduction, diffuse superficial punctate keratopathy in the right eye, and a central epithelial defect in the left eye. Seidel test results were negative for both eyes, with no corneal infiltration, lagophthalmos, anterior chamber cell precipitation, or retinal lesion. Symptoms subsequently resolved after reducing the frequency of afatinib used, along with intensive ocular hydration. In summary, this case highlighted afatinib's potential link to bilateral keratitis, and early afatinib dose adjustment with supportive medication could significantly reverse the condition.

[Subfamily of betaherpesviruses as a cause of epithelial and stromal keratitis]

PURPOSE

This article presents the first clinical results of intravital morphological verification of epithelial and stromal keratitis associated with betaherpesviruses.

MATERIAL AND METHODS

The study group included 12 patients (12 eyes) diagnosed with herpetic keratitis. During the initial visit to the clinic, each patient underwent a standard ophthalmological examination, as well as a number of laboratory tests: immunochemical analysis of blood, molecular diagnostics, and confocal microscopy. Histological study of the cornea was additionally performed in cases indicated for surgical treatment (2 patients).

RESULTS

According to enzyme-linked immunoelectrodiffusion essay (ELISA), acute-phase immunoglobulins of class M (Ig M) to cytomegalovirus (CMV) were detected in only one clinical case. Class G immunoglobulins (Ig G) to both CMV and human herpes virus type 6 (HHV-6) were detected in the majority of cases. Quantitative polymerase chain reaction (qPCR) revealed CMV DNA in tears (2 patients) and in saliva (4 patients). The HHV-6 genome was found in tears (2 patients) and in saliva (3 patients). According to the results of confocal microscopy, owl's eye cells were found in 8 patients of the group. Histological examination of the cornea helped identify pathognomonic cells in one case. Thus, 8 patients of the group were diagnosed with keratitis associated with the betaherpesvirus subfamily.

CONCLUSION

Results of observation of the study patients suggest the possibility of developing keratitis associated with the subfamily of betaherpesviruses with localization in the superficial layers of the cornea. Confocal microscopy can be useful for identification of pathognomonic owl's eye cells in the corneal tissues and confirmation of the diagnosis of betaherpesvirus-associated keratitis. Investigation of the etiological factor of superficial and stromal viral keratitis is important for determining the further tactics of pharmacotherapy.

Manifestations of coronavirus infection disease-19 in anterior eye segment: An up-to-date review

Coronavirus infection disease-19 (COVID-19) is a worldwide catastrophic emergency that first appeared in late 2019, in Wuhan, China. COVID-19 is a multitropism disease that first affects lung tissue. However, extrapulmonary manifestations have been suspected from the first COVID-19 cases. The ocular signs and symptoms were from the early changes that occur during the course of the disease. Changes in the anterior eye segment have a relatively higher incidence than the posterior eye segment. Of which, conjunctivitis, COVID-19 pharyngioceratoconjuctivitis, iridocyclitis, corneal punctate epitheliopathy, and pathomorphological changes in the physio-anatomy of the anterior eye segment. The potential pathogenesis includes direct penetration of the virus into the eye (conjunctiva, lumbus, and cornea) or due to a systemic pathway through viremia, as well as due to autoimmune antibodies against the ocular structure (immune privilege). The presence of ocular manifestations of the external anterior fibrous layer suggests a mild course of the disease.

infection in a horse: Clinical signs and successful topical therapy

Dermatological clinical signs have been seldom reported in the literature secondary to equine leishmaniasis. This case depicts the clinical signs, treatment, and outcome of a young horse with a pink, elevated lesion on the ventromedial quadrant of the cornea. A corneal cytology was performed and revealed the presence of leishmania amastigotes reaching the diagnosis of keratitis secondary to leishmania. Surgical resection was recommended but the owner declined the procedure, and the lesion was treated with a topical antimonial for 6 weeks. The lesion reduced remarkably during the first weeks of treatment. The patient had not shown recurrence of the lesion for 2 years since the treatment was started. Leishmania spp. can be responsible for ocular surface abnormalities such as keratitis. Corneal cytology is an inexpensive diagnostic method that should be considered when ocular surface abnormalities are identified in horses in endemic areas.

Impact of First Healthcare Provider on Acanthamoeba Keratitis Course: How to Overcome Poor Prognosis in Acanthamoeba Keratitis Treatment? A Single Tertiary Center, Observational Study

Background

To assess the difference in course and final visual outcome of Acanthamoeba keratitis (AK) patients based on the first healthcare provider (HCP) seen.

Methods

Retrospective observational cohort study of AK patients admitted to the Manchester Royal Eye Hospital between 2003 and 2017. HCPs were grouped (Group 1: Optometrists, Opticians; Group 2: General Practitioners (GPs); Group 3: Ophthalmologists) and the data analyzed on demographics, risk factors, clinical history, clinical features, and Acanthamoeba subspecies.

Results

Forty-one patients with unilateral culture-proven AK were included. Median time to consultation with first HCP was 7 days (IQR 4-14 days), while mean time to the correct diagnosis of AK was 15 days (IQR 7-29 days). Patients saw an optician, optometrist or ophthalmologists significantly earlier than GPs (median 4 days, vs 15 or 5 days, respectively, p = 0.04). Bacterial keratitis was the most common initial clinical diagnosis (43%). The shortest time to making the AK diagnosis (median 11 days) and the highest rate of initiating AK treatment started at the first visit (38%) were both in the ophthalmologists' group. No significant differences were observed in initial and final visual acuity between HCP groups (p = 0.36).

Conclusion

AK patients often seek ocular help earlier from optometrists and opticians than medical doctors. Final clinical outcomes did not significantly differ based on the first HCP seen, but ophthalmologists were more likely to make the diagnosis of AK and initiate anti-amoebal therapy faster than other HCPs. Greater education and collaboration between ophthalmologists and other HCPs to increase awareness of AK are needed.

Diagnostic performance of real-time quantitative PCR in tear samples in various subtypes of herpes simplex keratitis

Diagnosis of herpes simplex keratitis (HSK) is mostly based on clinical findings, yet biological confirmation supports management of challenging cases. This study evaluated the place of real-time quantitative PCR (RT-qPCR) on tear samplings in the management of HSK. Clinical records of patients who underwent tear sampling tested by RT-qPCR for herpes simplex virus type 1 for an acute episode of corneal inflammation or defect between January 2013 and December 2021 were retrospectively reviewed, and results were compared to clinical diagnosis (i.e., HSK or not) based on biomicroscopic findings and medical history. Of 465 tested tear samples from 364 patients, a clinical diagnosis of active (ongoing) HSK was recorded in 240 cases, among which 76 were RT-qPCR positive (global sensitivity of 31.6%, specificity of 99.5%). Sensitivity of RT-qPCR was higher in epithelial (97.4%) and stromal keratitis with ulceration (48.7%), compared to other types of HSK (23.5% in keratouveitis, 13.6% in endotheliitis, 11.1% in postherpetic neurotrophic keratopathy, and 8.1% in stromal keratitis without ulceration). The highest viral loads were detected from epithelial and stromal keratitis with ulceration, while in HSK with no epithelial involvement, the viral load detected was 196-fold lower, on average. The proportion of clinically characterized HSK patients with negative tear samples was higher in patients receiving antiviral treatment (P < 0.0001). RT-qPCR, performed on tear samples, can help in confirming diagnosis in case of presumed HSK, including clinical forms with no obvious epithelial involvement. The sensitivity of tear sampling is much higher whenever epithelial keratitis is present.

Antimicrobial Drug-Drug Interactions in the Treatment of Infectious Keratitis

PURPOSE

Infectious keratitis is a serious disease requiring immediate, intensive, and broad-spectrum empiric treatment to prevent vision loss. Given the diversity of organisms that can cause serious corneal disease, current guidelines recommend treatment with several antimicrobial agents simultaneously to provide adequate coverage while awaiting results of microbiology cultures. However, it is currently unknown how the use of multiple ophthalmic antimicrobial agents in combination may affect the efficacy of individual drugs.

METHODS

Using a panel of 9 ophthalmic antibiotics, 3 antifungal agents, and 2 antiacanthamoeba therapeutics, fractional inhibitory concentration testing in the standard checkerboard format was used to study 36 antibiotic-antibiotic combinations, 27 antibiotic-antifungal combinations, and 18 antibiotic-antiacanthamoeba combinations against both Staphylococcus aureus and Pseudomonas aeruginosa for synergistic, additive, neutral, or antagonistic drug-drug interactions.

RESULTS

We demonstrate that while most combinations resulted in no change in antimicrobial efficacy of individual components, the combination of erythromycin + polyhexamethylene biguanide was found to be antagonistic toward P. aeruginosa . Conversely, 18 combinations toward S. aureus and 15 combinations toward P. aeruginosa resulted in additive or synergistic activity, including 4 with improved activity toward both species.

CONCLUSIONS

Understanding how drug-drug interactions may affect drug efficacy is critical to selecting the appropriate combination therapy and improving clinical outcomes of this blinding disease.

Endothelial dysfunction of the cornea after exposure to sprayed venom from hornets

PURPOSE

Ocular injuries due to Hymenoptera venom are uncommon and most injuries occur on the ocular surface. We reported two rare cases of corneal endothelial damage caused by hornet venom that was sprayed, not injected, through stinging in the eye.

OBSERVATIONS

Case 1: A 57-year-old male patient was injured when a hornet sprayed venom into his left eye. He was referred to our hospital because the edoema and epithelial erosion of the cornea persisted. The patient presented with bullous keratopathy, asymmetrical iris atrophy, irreversible mydriasis, and glaucoma. His cataract progressed, and his best-corrected visual acuity was 0.03. Cataract surgery was performed after anti-inflammatory treatment with steroids, and Descemet-stripping automated endothelial keratoplasty was performed 6 months later. The patient recovered well postoperatively: his best-corrected visual acuity improved to 1.0 and he continued his glaucoma treatment. Case 2: A 75-year-old male patient had damage to his corneal epithelium, severe conjunctivitis, and conjunctival edoema when sprayed hornet venom entered his left eye. At initial presentation, the corneal endothelial cell density had decreased to 1042 cells/mm2. The conjunctival sac was washed, and steroid and topical antibacterial instillations were administered. His best-corrected visual acuity improved from 0.07 at the initial visit to 0.5. However, the corneal opacification and glaucoma persisted, and 3 months later the corneal endothelial cell density decreased to 846 cells/mm2.

CONCLUSIONS AND IMPORTANCE

Corneal injuries caused by sprayed hornet venom are rare; however, they can cause intense anterior chamber inflammation and severe, irreversible corneal endothelial damage. In such cases, prompt initial treatment, the administration of adequate anti-inflammatory medication, and careful evaluation of the corneal endothelium are required.

Iris depigmentation and cytomegalovirus in aqueous humor as predictors of uveitic activity and recurrence in chronic and recurrent anterior uveitis

PURPOSE

To examine the clinical outcomes in chronic or recurrent anterior uveitis in the presence or absence of cytomegalovirus (CMV) and investigate the predictive factors for uveitic activity and recurrence.

METHODS

Polymerase chain reaction (PCR) was performed in a prospective cohort of immunocompetent adults with recurrent or chronic anterior uveitis to detect CMV in aqueous humor. The clinical outcomes were compared between eyes with and without CMV DNA. Logistic regression was performed to evaluate associations between iris depigmentation, CMV-PCR status, uveitic activity, and recurrence.

RESULTS

Thirty-eight eyes of 38 subjects with a mean age of 61.1 ± 11.2 years old were analyzed. Fifteen eyes were positive for CMV. More eyes with CMV developed recurrences and remained actively inflamed at 6, 12, and 24 weeks though the differences were insignificant. The presence of iris depigmentation was predictive of a greater odd of uveitic recurrences by 12 and 24 weeks (Odds ratio (OR) = 9.17 and 5.72, P = 0.007 and 0.034 respectively), whereas positive CMV-PCR predicts a greater odd of uveitic activity at postoperative 12 and 24 weeks (OR = 13.08, 34.30; P = 0.027, 0.007).

CONCLUSION

Eye with and without detectable CMV behaved similarly in their clinical course. Our findings suggested that iris depigmentation was predictive of more frequent uveitic recurrence, regardless of the PCR status, whereas the presence of CMV in aqueous humor was associated with persistent uveitic activity. Iris changes may be present during the earlier phase of the disease and precede the detection of virus from the aqueous humor at a later stage of CMV infection.

Successful Treatment of Microsporidial Keratoconjunctivitis (MKC) With a Combination of Topical Voriconazole 1% and Gatifloxacin 0.5%: A Large Case Series of 29 Patients

OBJECTIVE

This study aims to report the successful treatment of microsporidial keratoconjunctivitis (MKC) with the combination of topical drops of voriconazole (1%) and gatifloxacin (0.5%) in all 29 patients. Demography, clinical profile, and previous treatment history were also analyzed.

METHODS

A retrospective, non-comparative case series of all Gram stain-proven MKC from September 2021 to October 2022 was included in this study. Patients were given antimicrobials such as topical drops of voriconazole 1%, gatifloxacin 0.5%, or a combination of both in 29 patients based on the treatment response. Topical steroids were added to 31 patients for corneal haziness.

RESULTS

A total of 33 patients were found to be positive for microsporidiosis confirmed by Gram staining. Twenty-four (72.7%) were men and nine (27.3%) were women. The mean age was 34.45±12. The presenting symptoms were mainly redness in 30 patients (90.9%), followed by watering in 13 (39.4%), foreign body sensation in 10 (30.3%), etc. Among the 23 patients (69%), a history of risk factors was identified, with 17 patients (51.5%) specifically reporting dust exposure as a major cause. MKCs were successfully treated with antimicrobials such as voriconazole 1% in three patients, gatifloxacin 0.5% in one patient, and a combination of both in 29 patients. Topical steroids were added to 31 patients for corneal haziness. At the last follow-up, a visually insignificant nummular corneal scar was noted in six patients. No drop in vision was noted in any of these patients at the end of the follow-up. No cases progressed to stromal keratitis and no surgical intervention was required in any cases.

CONCLUSIONS

We successfully treated all 29 cases with a combination of voriconazole and gatifloxacin without requiring any surgical intervention or encountering stromal complications. This successful treatment in all 29 cases offers valuable insights into the potential of this drug combination, possibly attributable to its additive action or broad-spectrum coverage across various species.

Ocular factors predicting requirement for corneal protective oculoplastic surgery

BACKGROUND

Currently there is no universally agreed schema for predicting ocular morbidity in facial nerve palsy. The House Brackmann Scale has limitations in assessing ocular morbidity from facial nerve palsy. Our aim was to create a scoring system to help quantify ocular morbidity to aid in decision making regarding the need for corneal protective oculoplastic surgery.

METHODS

We conducted a large cohort study observing 606 patients attending the specialist facial palsy clinic in Manchester UK between March 2002 and October 2017. Retrospective multivariate analysis identified clinical predictors for the 316 patients that required oculoplastic surgery. β coefficients generated in the multivariate analysis helped formulate a new facial nerve palsy scoring instrument to predict the need for corneal protective oculoplastic surgery.

RESULTS

The House Brackmann Scale, corneal lagophthalmos and loss of corneal sensation proved clinically significant predictors for requiring corneal protective oculoplastic surgery. The scoring system derived from these factors provided an accurate and repeatable prediction tool demonstrated by validation studies on our patient population. The area under the ROC curve for the multivariate prediction model was 0.769 (0.726, 0.811). A score of 5 points out of a possible 8 was the best cut off score to recommend oculoplastic surgery, giving a sensitivity of 0.750 and a specificity of 0.671.

CONCLUSION

This study demonstrates that corneal lagophthalmos, corneal sensation and the House Brackmann Scale are important in predicting the need for corneal protective oculoplastic surgery. Our scoring tool is an important clinical decision tool for ophthalmic and ENT colleagues.

Different Outcomes of Acanthamoeba Keratitis: A Case Series

Acanthamoeba keratitis is a potentially sight-threatening infection of the cornea that can lead to blindness. Over the past few decades, there has been a rise in the reported cases worldwide, which is in line with the increase of contact lens wearers. Here, we present three cases of Acanthamoeba keratitis with different outcomes.

Infectious crystalline keratopathy following Descemet's stripping automated endothelial keratoplasty

INTRODUCTION

We describe this first case of Staphylococcus epidermidis causing infectious crystalline keratopathy (ICK) following Descemet stripping endothelial keratoplasty (DSAEK), that resolved after 5 weeks of topical antibiotic and corticosteroid treatment.

CASE DESCRIPTION

An 80-year-old woman presented with blurred vision, redness, and ocular pain 9 months after successful DSAEK. Slit lamp examination revealed the presence of white, non-suppurative, deep-branching stromal infiltrates, and a clinical diagnosis of ICK was made. Cultures of corneal scapings isolated multidrug-resistant Staphylococcus epidermidis. No subsequent surgical procedures were performed. Based on antibiotic sensitivity analysis, she was treated successfully with topical vancomycin and chloramphenicol for 5 weeks. Complete resolution of the infection with minor anterior stromal corneal scarring of the host cornea was noted after 5 weeks of treatment. This case report describes the diagnosis and management of ICK after DSAEK and reviews the relevant literature regarding the occurrence of ICK after DSAEK.

CONCLUSION

In this case, vancomycin and chloramphenicol allowed for the uncomplicated resolution of infection with only minor visual impairment from baseline.

Diagnostic Potential of Anterior Segment Optical Coherence Tomography Scans for Pseudomonas Keratitis

Purpose

The purpose of this study was to investigate the diagnostic value of anterior segment optical coherence tomography (AS-OCT) scans for Pseudomonas keratitis.

Methods

Patients with treatment-naïve keratitis underwent AS-OCT imaging. The following parameters were evaluated: corneal thickness (CT), infiltrate thickness (IT), infiltrate diameter (ID), tissue loss/gain, entropy, and distance of the lesion from the corneal pupillary center. Three different OCT devices were used for the analysis. The relationship between the detected pathogen and the OCT patterns was analyzed.

Results

Nineteen eyes of 19 patients were included in the analysis: seven cases in the Pseudomonas group and 12 cases in the Gram-positive group. The mean (SD) values for the Pseudomonas and Gram-positive groups, respectively, were as follows: CT, 834 µm (165 µm) and 760 µm (120 µm); IT, 290 µm (152 µm) and 287 µm (84 µm); ID, 2067 µm (1470 µm) and 1307 µm (745 µm); distance to center, 3.0 mm (1.2 mm) and 3.0 mm (1.6 mm); epithelial defect, 1193 µm (586 µm) and 484 µm (615 µm); tissue gain, +31% (19%) and +10% (12%); and entropy level, 4.0 (0.8) and 3.9 (1.1).

Conclusions

This study introduces novel insights by identifying specific OCT parameters that distinguish Pseudomonas keratitis, including a 30% tissue gain. These findings align with earlier research that underscores the potential of OCT in differentiating various pathogens causing keratitis.

Translational Relevance

The findings of this study could be used to develop new diagnostic strategies for Pseudomonas keratitis. The OCT findings could be used to develop new biomarkers for the infection.

A rise in the frequency of lasR mutant Pseudomonas aeruginosa among keratitis isolates between 1993 and 2021

Introduction

Pseudomonas aeruginosa causes vision threatening keratitis. The LasR transcription factor regulates virulence factors in response to the quorum sensing molecule N-3-oxo-dodecanoyl-L-homoserine lactone. P. aeruginosa isolates with lasR mutations are characterized by an iridescent high sheen phenotype caused by a build-up of 2-heptyl-4-quinolone. A previous study demonstrated 22% (n=101) of P. aeruginosa keratitis isolates from India between 2010 and 2016 were sheen positive lasR mutants, and the sheen phenotype correlated with worse clinical outcomes for patients. In this study, a longitudinal collection of P. aeruginosa keratitis isolates from Eastern North America were screened for lasR mutations by the sheen phenotype and sequencing of the lasR gene.

Methods

Keratitis isolates (n=399) were classified by sheen phenotype. The lasR gene was cloned from a subset of isolates, sequenced, and tested for loss of function or dominant-negative status based on an azocasein protease assay. A retrospective chart review compared outcomes of keratitis patients infected by sheen positive and negative isolates.

Results

A significant increase in sheen positive isolates was observed between 1993 and 2021. Extracellular protease activity was reduced among the sheen positive isolates and a defined lasR mutant. Cloned lasR alleles from the sheen positive isolates were loss of function or dominant negative and differed in sequence from previously reported ocular lasR mutant alleles. Retrospective analysis of patient information suggested significantly better visual outcomes for patients infected by sheen positive isolates.

Discussion

These results indicate an increase in lasR mutations among keratitis isolates in the United States and suggest that endemic lasR mutants can cause keratitis.

Artificial Intelligence and Infectious Keratitis: Where Are We Now?

Infectious keratitis (IK), which is one of the most common and catastrophic ophthalmic emergencies, accounts for the leading cause of corneal blindness worldwide. Different pathogens, including bacteria, viruses, fungi, and parasites, can cause IK. The diagnosis and etiology detection of IK pose specific challenges, and delayed or incorrect diagnosis can significantly worsen the outcome. Currently, this process is mainly performed based on slit-lamp findings, corneal smear and culture, tissue biopsy, PCR, and confocal microscopy. However, these diagnostic methods have their drawbacks, including experience dependency, tissue damage, cost, and time consumption. Diagnosis and etiology detection of IK can be especially challenging in rural areas or in countries with limited resources. In recent years, artificial intelligence (AI) has opened new windows in medical fields such as ophthalmology. An increasing number of studies have utilized AI in the diagnosis of anterior segment diseases such as IK. Several studies have demonstrated that AI algorithms can diagnose and detect the etiology of IK accurately and fast, which can be valuable, especially in remote areas and in countries with limited resources. Herein, we provided a comprehensive update on the utility of AI in IK.

Intracellular replication of Pseudomonas aeruginosa in epithelial cells requires suppression of the caspase-4 inflammasome

Pathogenesis of Pseudomonas aeruginosa infections can include bacterial survival inside epithelial cells. Previously, we showed that this involves multiple roles played by the type three secretion system (T3SS), and specifically the effector ExoS. This includes ExoS-dependent inhibition of a lytic host cell response that subsequently enables intracellular replication. Here, we studied the underlying cell death response to intracellular P. aeruginosa, comparing wild-type to T3SS mutants varying in capacity to induce cell death and that localize to different intracellular compartments. Results showed that corneal epithelial cell death induced by intracellular P. aeruginosa lacking the T3SS, which remains in vacuoles, correlated with the activation of nuclear factor-κB as measured by p65 relocalization and tumor necrosis factor alpha transcription and secretion. Deletion of caspase-4 through CRISPR-Cas9 mutagenesis delayed cell death caused by these intracellular T3SS mutants. Caspase-4 deletion also countered more rapid cell death caused by T3SS effector-null mutants still expressing the T3SS apparatus that traffic to the host cell cytoplasm, and in doing so rescued intracellular replication normally dependent on ExoS. While HeLa cells lacked a lytic death response to T3SS mutants, it was found to be enabled by interferon gamma treatment. Together, these results show that epithelial cells can activate the noncanonical inflammasome pathway to limit proliferation of intracellular P. aeruginosa, not fully dependent on bacterially driven vacuole escape. Since ExoS inhibits the lytic response, the data implicate targeting of caspase-4, an intracellular pattern recognition receptor, as another contributor to the role of ExoS in the intracellular lifestyle of P. aeruginosa. IMPORTANCE Pseudomonas aeruginosa can exhibit an intracellular lifestyle within epithelial cells in vivo and in vitro. The type three secretion system (T3SS) effector ExoS contributes via multiple mechanisms, including extending the life of invaded host cells. Here, we aimed to understand the underlying cell death inhibited by ExoS when P. aeruginosa is intracellular. Results showed that intracellular P. aeruginosa lacking T3SS effectors could elicit rapid cell lysis via the noncanonical inflammasome pathway. Caspase-4 contributed to cell lysis even when the intracellular bacteria lacked the entire T33S and were consequently unable to escape vacuoles, representing a naturally occurring subpopulation during wild-type infection. Together, the data show the caspase-4 inflammasome as an epithelial cell defense against intracellular P. aeruginosa, and implicate its targeting as another mechanism by which ExoS preserves the host cell replicative niche.

Ocular surface toxicities associated with modern anticancer therapies

Cancer treatments have recently shifted from broad-spectrum cytotoxic therapies to more focused treatments, maximizing anti-cancerous activity while reducing toxicity to healthy cells. These modern anticancer therapies (MATs) encompass a wide range of innovative molecules that mainly include immune checkpoint inhibitors (ICIs) and targeted anticancer therapies (TATs), comprising antibody drug conjugates (ADCs) and inhibitors of signal transduction (IST). Some MATs are associated with ocular surface (OS) adverse events (AEs) that can cause severe discomfort and even lead to loss of vision. While these complications remain rare, they're probably underreported. It is likely that both oncologists and ophthalmologists will come across MATs-associated OS-AEs in their practices, due to the increasing number of patients being treated with MATs. Rapid identification of OS-AEs is crucial, as early intervention can manage these conditions to avoid vision loss and reduce negative impacts on quality of life (QoL). We discuss characteristics of OS pathologies attributed to MATs, describe the suspected underlying pathophysiological mechanisms, and outline the main lines of treatment.

Multi-Target Effect of Aloeresin-A against Bacterial and Host Inflammatory Targets Benefits Contact Lens-Related Keratitis: A Multi-Omics and Quantum Chemical Investigation

Contact lens-mediated microbial keratitis caused by Pseudomonas aeruginosa and Streptococcus pneumoniae provokes corneal damage and vision loss. Recently, natural phytochemicals have become complementary medicines for corneal destruction. Herein, we aimed to identify multi-targeting Aloe vera-derived phytochemicals capable of inhibiting bacterial and host targets of keratitis through ADME (absorption, distribution, metabolism, and excretion), docking, molecular dynamics (MD) simulation, MMGBSA (molecular mechanics generalized Born surface area) and density functional theory (DFT) investigations. An extensive literature search revealed ExoU, ExoS, ExoT, ExoY, and PLY as virulent bacterial targets. Simultaneously, differential gene expression (DGE) and pathway enrichment analysis-specified host transcription factor (SPI1) influences keratitis pathogenesis. Molecular docking analysis uncovered aloeresin-A as a promising inhibitor against bacterial and host targets, demonstrating strong binding energies ranging from -7.59 to -6.20 kcal/mol. Further, MMGBSA and MD simulation analysis reflect higher binding free energies and stable interactions of aloeresin-A with the targets. In addition, DFT studies reveal the chemical reactiveness of aloeresin-A through quantum chemical calculations. Hence, our findings show aloeresin-A to be a promising candidate for effectively inhibiting keratitis. However, additional research is imperative for potential integration into lens care solutions.

Ciclosporin A Cationic Emulsion 0.1% for the Management of Dry Eye Disease: Facts That Matter for Eye-Care Providers

Dry eye disease (DED) is a chronic inflammatory disease of the ocular surface requiring long-term therapy. Severe forms of DED generally do not respond to tear substitutes alone or combined, and often require treatment with topical anti-inflammatory agents to break the vicious circle of inflammation. This review summarises data from randomised controlled trials and real-world evidence on the efficacy and safety of ciclosporin A 0.1% cationic emulsion (Ikervis®) for the management of DED. Improvements in clinical signs and symptoms were reported from as early as 4 weeks after treatment initiation, although it can take a few months to reach the full benefits. Treatment periods of up to 12 months provide sustained benefit to patients. In the most responsive patients, treatment discontinuation is possible with no further substantial relapse over 12 months in over 65% of patients. Transient local ocular effects are the most commonly reported adverse events.

Silver@Prussian Blue Core-Satellite Nanostructures as Multimetal Ions Switch for Potent Zero-Background SERS Bioimaging-Guided Chronic Wound Healing

Metal-organic framework-based metal ion therapy has attracted increasing attention to promote the cascade wound-healing process. However, multimetal ion synergistic administration and accurately controlled ion release are still the challenges. Herein, an aptamer-functionalized silver@cupriferous Prussian blue (ACPA) is established as a metal-based theranostic nanoagent for a chronic nonhealing diabetic wound treatment. Prussian blue offers a programmable nanoplatform to formulate metal ion prescriptions, achieving cooperative wound healing. Silver, copper, and iron ions are released from ACPA controlled by the near-infrared-triggered mild hyperthermia and then synergistically participate in antipathogen, cell migration, and revascularization. ACPA also demonstrates a unique core-satellite nanostructure which enables it with improved surface-enhanced Raman scattering (SERS) capability as potent bacteria-targeted Raman-silent nanoprobe to monitor the residual bacteria during wound healing with nearly zero background. The theranostic feature of ACPA allows high-performance SERS imaging-guided chronic wound healing in infectious diabetic skin and keratitis.

Herpetic anterior uveitis following COVID-19 vaccines: a case series

Purpose

To report a case series of herpetic uveitis following COVID-19 vaccinations.

Methods

Demographic, clinical and treatment-related data of herpetic anterior uveitis cases was collected at five tertiary eye hospitals between January 2021 and June 2022. A retrospective database review at one of the centers comparing the number of cases of herpetic eye disease before and after the introduction of COVID-19 vaccination was performed as well.

Results

Twenty-four patients (9 female, 15 male) with a mean age of 54 years (range 28-83 years) were diagnosed with herpetic uveitis, reporting an onset of symptoms 3-42 days after the first, second or third dose of COVID-19 vaccination. Median time between vaccination and onset of herpetic eye disease was 10 days (mean 12.7 ± 10.15 days) days. The administered vaccines were BNT162b2, mRNA-1273, BBIBP-CorV and Ad26.COV2.S. The cases included 11 HSV, 10 VZV and 1 CMV anterior uveitis, 2 were not further specified. There was an equal number of first episodes (n = 12, 50%) and recurrent episodes (n = 12, 50%). Response to established regimens was generally good. The retrospective database review revealed the exact same incidence of herpetic uveitis during the pandemic and ongoing vaccination compared to prior SARS-CoV-2.

Conclusion

This report includes 24 cases of herpetic anterior uveitis in a temporal relationship to various COVID-19 vaccines. This study supports the potential risk of herpetic eye disease following COVID-19 vaccines, but proof of a direct, causal relationship is missing.

Cure of mycobacterium avium keratitis caused by trauma in elderly: case report

We report a case of Mycobacterium avium keratitis, first detected in the laboratory, which is from an 81-year-old female patient with a 13-year history of recurrent keratitis after eye injuries. This patient underwent anterior chamber irrigation of the right eye, and autologous conjunctival flap covering plus medication, and the corneal ulcer healed. She recovered well after continuing with the medication for half a year. The patient was not immune-compromised. Complex eye diseases such as blurred vision and cataracts caused by advanced age, delayed symptoms caused by slow growth of Mycobacterium avium and low-grade inflammation, difficulty with laboratory culture, repeated medication use, and repeated illnesses were the main reasons for the prolonged failure to clarify the etiology of this case. Morphological examination provided important clues for the initial discovery of pathogenic bacteria. Remind to pay attention to the morphology of Mycobacterium under Gram staining and Rui's Giemsa staining. Acid fast staining and Deoxyribonucleic Acid(DNA) microarray chip method can be used as indicators for rapid diagnosis of Mycobacterium species.

Cefiderocol is an effective topical monotherapy for experimental extensively-drug resistant Pseudomonas aeruginosa keratitis

Purpose

To test cefiderocol, a siderophore-cephalosporin antibiotic for topical monotherapy treatment of experimental extensively drug resistant (XDR) Pseudomonas aeruginosa keratitis.

Design

Preclinical study.

Subjects and Controls

Deidentified P. aeruginosa keratitis isolates, XDR P. aeruginosa from eye drop outbreak, rabbits, saline, cefiderocol 50 mg/ml, ciprofloxacin 0.3%, and tobramycin 14 mg/ml.

Methods Intervention or Testing

Cefiderocol antibacterial activity against P. aeruginosa keratitis isolates (n=135) was evaluated by minimum inhibitory concentration (MIC) testing. Ocular toxicity/tolerability and antibacterial efficacy were tested in vivo with experimental rabbit models. Corneal concentrations and stability were assessed using a bioassay.

Main Outcome Measures

MIC analysis for susceptibility, graded tests for ocular toxicity/tolerability, CFU analysis for bacterial burden, corneal cefiderocol concentrations.

Results

100% of P. aeruginosa keratitis isolates were susceptible to cefiderocol (n=135), the MIC90 was 0.125 μg/ml including the XDR isolate (MIC = 0.125 μg/ml). Topical cefiderocol 50 mg/ml was minimally toxic to the ocular surface and was well tolerated. For the XDR P. aeruginosa isolate, topical cefiderocol 50 mg/ml, significantly decreased corneal CFU compared to ciprofloxacin 0.3%, tobramycin 14 mg/ml, and saline. In addition, tobramycin 14 mg/ml was more effective than the saline control. Mean cefiderocol corneal concentrations were 191x greater than the MIC90 of the P. aeruginosa keratitis isolates. Refrigerated cefiderocol maintained antimicrobial activity over a one-month period.

Conclusions

These results demonstrate that cefiderocol is well tolerated on rabbit corneas and is effective against P. aeruginosa keratitis isolates in vitro and was effective in vivo against an XDR isolate in a rabbit keratitis model. Given the recent outbreak of keratitis caused by this XDR P. aeruginosa, cefiderocol is a promising additional antibiotic that should be further evaluated for topical treatment of keratitis caused by antibiotic resistant P. aeruginosa.

Bleb Associated Xen Gel Stent Endophthalmitis: A Case Report and Review of Literature

PURPOSE

To report a case of a unique late complication of the Xen gel stent, stent-related endophthalmitis was preceded by flattening of the bleb.

CASE REPORT

A 63-year-old female was presented with late-onset endophthalmitis preceded by flattening of the bleb two years post-insertion of Xen gel stent. B-scan of the posterior chamber revealed vitritis and hyaloid condensation, with no viral, fungal, or bacterial pathologies identified on anterior chamber tap. The patient's eye responded to injections of intravitreal antibiotics.

CONCLUSION

Endophthalmitis can occur as late as 2 years after implantation of glaucoma drainage device implants (GDIs) like the Xen gel stent if bleb flattening or leaking leads to contact of the stent with the conjunctiva. Therefore, in case of blebs getting flat, ophthalmologists should watch them more often. Intravitreal antibiotics may also be effective rather than surgical removal in the case of a non-eroded stent complicated by endophthalmitis.

High-Fluence Accelerated PACK-CXL for Bacterial Keratitis Using Riboflavin/UV-A or Rose Bengal/Green in the Ex Vivo Porcine Cornea

Purpose

To investigate and compare the efficacy of high-fluence accelerated photoactivated chromophore for keratitis-corneal cross-linking (PACK-CXL) using either riboflavin/ultraviolet (UV)-A light or rose bengal/green light to treat Staphylococcus aureus or Pseudomonas aeruginosa infections in an ex vivo porcine cornea model.

Methods

One hundred and seventeen ex vivo porcine corneas were injected with clinical isolates of S. aureus or P. aeruginosa, divided into eight groups, and cultured for 24 hours. Then, either riboflavin with UV-A light irradiation (30 mW/cm2; 8 minutes, 20 seconds; 15 J/cm2) or rose bengal with green light irradiation (15 mW/cm2, 16 minutes, 40 seconds; 15 J/cm2) was applied; unirradiated infected groups served as controls. All corneas were incubated for another 24 hours. Next, corneal buttons were obtained and vortexed to release the bacterial cells. The irradiated and unirradiated solutions were then plated and incubated on agar plates. The amount of colony-forming units was quantified and the bacterial killing ratios (BKRs) resulting from different PACK-CXL protocols relative to non-treated controls were calculated.

Results

Riboflavin/UV-A light PACK-CXL resulted in median BKRs of 52.8% and 45.8% in S. aureus and P. aeruginosa, respectively, whereas rose bengal/green light PACK-CXL resulted in significantly greater BKRs of 76.7% and 81.0%, respectively (both P < 0.01).

Conclusions

Both accelerated PACK-CXL protocols significantly decreased S. aureus and P. aeruginosa bacterial loads. Comparing the riboflavin/UV-A light and rose bengal/green light PACK-CXL approaches in the same experimental setup may help develop strain-specific and depth-dependent PACK-CXL approaches that could be used alongside the current standard of care.

Translational Relevance

Our study used an animal model to gain insight into the efficacy of high-fluence accelerated PACK-CXL using either riboflavin/UV-A light or rose bengal/green light to treat Staphylococcus aureus or Pseudomonas aeruginosa infections.

A 7-year review of clinical characteristics, predisposing factors and outcomes of post-keratoplasty infectious keratitis: the Nottingham infectious keratitis study

Background/objectives

Post-keratoplasty infectious keratitis (PKIK) is a unique sight-threatening clinical entity which often poses significant therapeutic challenges. This study aimed to examine the clinical presentation, risk factors, management, and clinical outcomes of PKIK.

Methods

This was a retrospective study of all patients who presented to the Queen's Medical Centre, Nottingham, with PKIK between September 2015 and August 2022 (a 7-year period). Relevant data on types of keratoplasty, clinical presentations, causative microorganisms, management, and outcome were analyzed.

Results

Forty-nine PKIK cases, including four cases of interface infectious keratitis, were identified during the study period. The most common graft indications for PKP, DALK and EK were failed grafts (9, 37.5%), keratoconus (6, 54.5%) and Fuchs endothelial corneal dystrophy (FECD; 8, 57.1%), respectively. Staphylococcus spp. were the most commonly identified organisms (15, 50.0%). Bullous keratopathy (18, 36.7%), ocular surface disease (18, 36.7%), and broken/loose sutures (15, 30.6%) were the most common risk factors. Concurrent use of topical steroids was identified in 25 (51.0%) cases. Of 31 functioning grafts at presentation, 12 (38.7%) grafts failed at final follow-up with 15 (48.4%) patients retaining a CDVA of ≥1.0 logMAR. The overall estimated 5-year survival rate post-PKIK was 55.9% (95% CI, 35.9%-75.9%), with DALK having the highest survival rate [63.6% (95% CI, 28.9%-98.3%)], followed by EK [57.1% (95% CI, 20.4%-93.8%)] and PKP [52.7% (95% CI, 25.1%-80.3%)], though no statistical difference was observed (p=0.48).

Conclusions

PKIK represents an important cause of IK and graft failure. Bullous keratopathy, OSD and suture-related complications are the commonest risk factors, highlighting the potential benefit of prophylactic topical antibiotics (for unhealthy ocular surface) and early suture removal (where possible) in reducing the risk of PKIK. Graft survival may be higher in lamellar keratoplasty following PKIK but larger studies are required to elucidate this observation.

Therapeutic potential of Bacillus phage lysin PlyB in ocular infections

Bacteriophage lytic enzymes (i.e., phage lysins) are a trending alternative for general antibiotics to combat growing antimicrobial resistance. Gram-positive Bacillus cereus causes one of the most severe forms of intraocular infection, often resulting in complete vision loss. It is an inherently β-lactamase-resistant organism that is highly inflammogenic in the eye, and antibiotics are not often beneficial as the sole therapeutic option for these blinding infections. The use of phage lysins as a treatment for B. cereus ocular infection has never been tested or reported. In this study, the phage lysin PlyB was tested in vitro, demonstrating rapid killing of vegetative B. cereus but not its spores. PlyB was also highly group specific and effectively killed the bacteria in various bacterial growth conditions, including ex vivo rabbit vitreous (Vit). Furthermore, PlyB demonstrated no cytotoxic or hemolytic activity toward human retinal cells or erythrocytes and did not trigger innate activation. In in vivo therapeutic experiments, PlyB was effective in killing B. cereus when administered intravitreally in an experimental endophthalmitis model and topically in an experimental keratitis model. In both models of ocular infection, the effective bactericidal property of PlyB prevented pathological damage to ocular tissues. Thus, PlyB was found to be safe and effective in killing B. cereus in the eye, greatly improving an otherwise devastating outcome. Overall, this study demonstrates that PlyB is a promising therapeutic option for B. cereus eye infections.IMPORTANCEEye infections from antibiotic-resistant Bacillus cereus are devastating and can result in blindness with few available treatment options. Bacteriophage lysins are an alternative to conventional antibiotics with the potential to control antibiotic-resistant bacteria. This study demonstrates that a lysin called PlyB can effectively kill B. cereus in two models of B. cereus eye infections, thus treating and preventing the blinding effects of these infections.

Rise in frequency of lasR mutant Pseudomonas aeruginosa among keratitis isolates between 1993 and 2021

Pseudomonas aeruginosa causes severe vision threatening keratitis. LasR is a transcription factor that regulates virulence associated genes in response to the quorum sensing molecule N-3-oxo-dodecanoyl-L-homoserine lactone. P. aeruginosa isolates with lasR mutations are characterized by an iridescent high sheen phenotype caused by a build-up of 2-heptyl-4-quinolone. A previous study indicated a high proportion (22 out of 101) of P. aeruginosa keratitis isolates from India between 2010 and 2016 were sheen positive and had mutations in the lasR gene, and the sheen phenotype correlated with worse clinical outcomes for patients. In this study, a longitudinal collection of P. aeruginosa keratitis isolates from Eastern North America were screened for lasR mutations by the sheen phenotype and sequencing of the lasR gene. A significant increase in the frequency of isolates with the sheen positive phenotype was observed in isolates between 1993 and 2021. Extracellular protease activity was lower among the sheen positive isolates and a defined lasR mutant. Cloned lasR alleles from the sheen positive isolates were loss of function or dominant negative and differed in sequence from previously reported ocular lasR mutant alleles. Insertion elements were present in a subset of independent isolates and may represent an endemic source from some of the isolates. Retrospective analysis of patient information suggested significantly better visual outcomes for patients with infected by sheen positive isolates. Together, these results indicate an increasing trend towards lasR mutations among keratitis isolates at a tertiary eye care hospital in the United States.