Corneal Specimens Research Articles

Mpox Keratouveitis: A Clinical Analysis of Host Immune Responses

Purpose: To describe 2 patients with mpox keratouveitis and evaluate their contrasting clinical phenotypes in the context of baseline immune function. Methods: Both patients were subject to longitudinal care by providers at our institution. Qualitative polymerase chain reaction (PCR) analysis was used to confirm their diagnoses, and interval slit-lamp photography was used to document their clinical progression. For case 2, histologic analysis was performed on a corneal biopsy specimen. Results: Case 1 describes a 31-year-old immunocompetent man with cutaneous mpox who developed a unilateral keratouveitis after a cutaneous lesion of the ipsilateral eyelid. His keratitis resolved over 1 week with application of trifluridine eye drops. An anterior uveitis persisted but resolved by 2 weeks after treatment with topical prednisolone and oral tecovirimat. Case 2 describes a 27-year-old man with HIV and a declining CD4+ count who was coinfected with monkeypox virus. Over 3 months, he developed a progressive unilateral keratouveitis that resulted in corneal melt requiring tectonic keratoplasty to preserve globe integrity. On histology, the patient's corneal biopsy specimen was devoid of lymphocytes. Conclusions: Contrary to immunocompetent patients, individuals with profound cell-mediated immunodeficiencies may be unable to mount sufficient lymphocytic responses in corneal tissue to contain mpox lesions. A progressive keratouveitis can develop, leading to corneal melt with an atypical local immune signature. The clinical and histologic phenotype of the cornea in this scenario is analogous to progressive vaccinia of the skin, a rare clinical entity that develops after smallpox vaccination of immunocompromised hosts.

A single-center study on the distribution and shifting trend of infectious keratitis pathogens from 2018 to 2022

Objective: To investigate the pathogen species, composition, and distribution characteristics of infectious keratitis pathogens in Shandong Province and its surrounding areas. Methods: In this cross-sectional study, patients with keratitis who underwent corneal sampling and microbiological culture at the Shandong Eye Hospital from January 1, 2018 to December 31, 2022 were included. Under topical anesthesia, the edge of the lesion was scraped by an experienced physician. The samples were inoculated on blood agar and Sabouraud dextrose agar plates, separately for bacterial and fungal culture and identification. If necessary, the samples were inoculated on a non-nutrient agar medium with Escherichia coli for Acanthamoeba culture. Bacterial isolates were identified using Vitek 2 compact or matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Fungal isolates were identified based on morphological characteristics or sent to a company for sequencing in cases of difficult identification. The epidemiological data of the patients, pathogen species and number (counting as 1 strain if the same strain was isolated from multiple corneal specimens of the same patient), culture positivity rate, and seasonal distribution were recorded. Differences in pathogen positivity rates among different seasons were analyzed using the chi-square test. Results: Among the 4, 024 patients with infectious keratitis during the study period, there were 2 510 males (62.3%) and 1 514 females (37.6%), aged from 46 days to 94 years. Positive microbial culture results were achieved in 2, 363 patients (58.7%), including 906 cases (38.3%) with bacterial positivity, 1 231 cases (52.1%) with fungal positivity, 28 cases (1.2%) with Acanthamoeba positivity, and 198 cases (8.4%) with mixed fungal and bacterial infections. A total of 2 561 strains were isolated, including 1 104 bacterial strains. The most common bacteria were coagulase-negative Staphylococcus spp. (623/1 104, 56.4%), followed by Streptococcus spp. (131/1 104, 11.9%) and Pseudomonas aeruginosa (68/1 104, 6.2%). The most common fungi were Fusarium spp. (634/1 429, 44.4%), followed by Aspergillus spp. (279/1 429, 19.5%) and Alternaria spp. (229/1 429, 16.0%). Bacterial keratitis was more common in summer and autumn, while fungal keratitis was more common in autumn and winter. Conclusions: Among infectious keratitis cases in Shandong Eye Hospital, Fusarium species were predominant fungal pathogens, while coagulase-negative Staphylococcus predominated in bacterial pathogens. Both fungal and bacterial corneal infections showed seasonal variations.

A Case of Fulminant Serratia marcescens Panophthalmitis After Penetrating Keratoplasty

Purpose: To report the first case of fulminant Serratia marcescens panophthalmitis after penetrating keratoplasty (PK). Methods: This is a report of a patient who developed fulminant panophthalmitis shortly after undergoing PK with anterior chamber intraocular lens placement. Slit-lamp examination, B-scan ultrasound (B scan), and orbital computed tomography of the left eye (OS) were performed to further evaluate the patient. Tissue culture and histopathologic examination of the corneal specimen were completed to confirm the diagnosis. Results: A 78-year-old pseudophakic woman presented with 2 days of increasing pain, swelling, and purulent discharge after uneventful PK and secondary anterior chamber intraocular lens placement OS. Examination was notable for light perception without projection, elevated intraocular pressure of 48 mmHg, and a perforated corneal ulcer. B scan demonstrated diffuse vitreous opacities and membranes. Orbital computed tomography demonstrated proptosis and high-attenuation material within the left globe. Canthotomy, vitreous sampling, and antibiotic injections were performed. Corneal tissue cultures grew S. marcescens. Therapeutic PK was performed, but after rapid decompensation, the eye was eviscerated. Conclusions: This is the only reported case of fulminant S. marcescens panophthalmitis after PK. S. marcescens panophthalmitis is an aggressive and rapidly progressive infection with poor visual outcomes despite appropriate intravitreal and systemic antibiotic therapy.

Effect of Mesenchymal Stem Cells-Derived Exosomes on Healing of a Rabbit Model of Corneal Alkali Burn. Histological and Immunohistochemical Study

Abstract Introduction Corneal alkali burn is one of the most severe ophthalmic emergencies that requires prompt treatment. Recently, the attention of researchers has been attracted to the use of exosomes as a novel non-cell therapy for treatment of corneal alkali burn. Aim to evaluate the possible role of mesenchymal stem cells (MSCs)-derived exosomes on healing of experimentally induced corneal alkali burn in rabbits by histological and immunohistochemical techniques. Materials and Methods Forty-five adult male New Zealand white rabbits were divided into three groups: group I (control group); group II in which corneal alkali burn was left for spontaneous healing, and group III (exosomes treated group): in which rabbits received a sub-conjunctival injection of 100 μg MSCs-exosomes after one hour from corneal alkali burn induction. Injection of exosomes was repeated every other day. All groups were further subdivided into two subgroups; subgroup A and B, where corneal specimens were collected after 7 days and 14 days, respectively. Characterization of exosomes was done using transmission electron microscope. Gross examination of the cornea was done at days 0, 1, 4,7,10 and 14. At the end of experiment, corneal specimens were collected and subjected to hematoxylin and eosin, Masson`s trichrome, periodic acid Schiff, transforming growth factor-beta and vascular endothelial growth factor immunohistochemical techniques. Histo-morphometric study and statistical analysis were also done. Results Administration of MSCs-derived exosomes in group III improved healing of corneal alkali burn by inhibiting angiogenesis and inflammation, enhancing corneal reepithelization, and providing better organization of newly formed stromal collagen fibers. Conclusion Sub-conjunctival injection of MSCs-derived exosomes could be effective in the healing of corneal alkali burn in adult rabbits.

Unveiling challenging corneal infections: a comprehensive etiological diagnosis through metagenomic next-generation sequencing (mNGS) of corneal tissue samples.

The objective of this study was to assess the clinical diagnostic value of metagenomic next-generation sequencing (mNGS) in cases of challenging corneal infections using corneal tissue samples. This retrospective study involved 42 patients with corneal infections, where conventional diagnostic techniques failed to identify the causative pathogen. Corneal tissue specimens underwent mNGS, followed by microbial culture for validation. Sensitivity-guided antimicrobial therapy was administered upon identification of the pathogen. The diagnostic and therapeutic efficacy of mNGS was analyzed to evaluate its clinical utility. A total of 42 patients were included in this study, with mNGS detection results obtained for 38 cases (90.48%). Among them, 30 cases (71.43%) were clinically significant, eight cases (19.05%) had low clinical relevance, and four cases (9.52%) showed no detection. Following corresponding antimicrobial treatment, 30 patients exhibited significant improvement, resulting in a treatment effectiveness of 71.43%. The prognosis of mNGS-positive patients was superior to that of mNGS-negative patients, with statistically significant differences observed (P < 0.001). Corneal tissue mNGS facilitated the rapid identification of causative agents in challenging corneal infections with unclear clinical diagnoses. It could be seamlessly integrated with traditional diagnostic methods to guide the diagnosis and treatment of corneal diseases.

Transcriptional profiling specifies the pathogen-specific human host response to infectious keratitis.

Corneal infections are a leading cause of visual impairment and blindness worldwide. Here we applied high-resolution transcriptomic profiling to assess the general and pathogen-specific molecular and cellular mechanisms during human corneal infection. Clinical diagnoses of herpes simplex virus (HSV) (n=5) and bacterial/fungal (n=5) keratitis were confirmed by histology. Healthy corneas (n=7) and keratoconus (n=4) samples served as controls. Formalin-fixed, paraffin-embedded (FFPE) human corneal specimens were analyzed using the 3' RNA sequencing method Massive Analysis of cDNA Ends (MACE RNA-seq). The cellular host response was investigated using comprehensive bioinformatic deconvolution (xCell and CYBERSORTx) analyses and by integration with published single cell RNA-seq data of the human cornea. Our analysis identified 216 and 561 genes, that were specifically overexpressed in viral or bacterial/fungal keratitis, respectively, and allowed to distinguish the two etiologies. The virus-specific host response was driven by adaptive immunity and associated molecular signaling pathways, whereas the bacterial/fungal-specific host response mainly involved innate immunity signaling pathways and cell types. We identified several genes and pathways involved in the host response to infectious keratitis, including CXCL9, CXCR3, and MMP9 for viral, and S100A8/A9, MMP9, and the IL17 pathway for bacterial/fungal keratitis. High-resolution molecular profiling provides new insights into the human corneal host response to viral and bacterial/fungal infection. Pathogen-specific molecular profiles may provide the foundation for novel diagnostic biomarker and therapeutic approaches that target inflammation-induced damage to corneal host cells with the goal to improve the outcome of infectious keratitis.

In the eye of the ophthalmologist: the corneal microbiome in microbial keratitis.

To describe the bacterial findings by a targeted sequencing approach from corneal samples of patients with microbial keratitis and factors influencing culture outcome of indirectly inoculated corneal specimen. Prospective inclusion of patients fulfilling predefined criteria of microbial keratitis. Samples from the corneal lesion were collected and dispensed in liquid transport medium, from which both culture and targeted amplification and sequencing of the V3-V4 region of the 16S rRNA gene were carried out. Additional standard corneal culture from the corneal lesions was also performed. Factors influencing culture outcome of indirectly inoculated corneal samples were identified by a multivariate regression model incorporating quantitative data from sequencing. Among the 94 included patients with microbial keratitis, contact lens wear (n = 69; 73%) was the most common risk factor. Contact lens wearers displayed significant differences in the bacterial community composition of the corneal lesion compared to no lens wearers, with higher abundance of Staphylococcus spp., Corynebacterium spp., and Stenotrophomonas maltophilia. Targeted sequencing detected a potential corneal pathogen in the highest proportional abundance among 9 of the 24 (38%) culture-negative patients with microbial keratitis. Age, bacterial density in the sample, and prior antibiotic treatment significantly influenced culture outcome of indirectly inoculated corneal samples. Targeted sequencing may provide insights on pathogens in both culture negative episodes of microbial keratitis and among subgroups of patients with microbial keratitis as well as factors influencing culture outcome of indirectly inoculated corneal samples.

Biaxial hyperelastic and anisotropic behaviors of the corneal anterior central stroma along the preferential fibril orientations. Part I: Measurement and calibration of personalized stress-strain curves

Lacking specimens is the biggest limitation of studying the mechanical behaviors of human corneal. Extracting stress-strain curves is the crucial step in investigating hyperelastic and anisotropic properties of human cornea. 15 human corneal specimens extracted from the small incision lenticule extraction (SMILE) surgery were applied in this study. To accurately measure the personalized true stress-strain curve using corneal lenticules, the digital image correlation (DIC) method and finite element method were used to calibrate the stress and the strain of the biaxial extension test. The hyperelastic load-displacement curves obtained from the biaxial extension test were performed in preferential fibril orientations, which are arranged along the nasal-temporal (NT) and the superior-inferior (SI) directions within the anterior central stroma. The displacement and strain fields were accurately calibrated and calculated using the digital image correlation (DIC) method. A conversion equation was given to convert the effective engineering strain to the true strain. The stress field distribution, which was simulated using the finite element method, was verified. Based on this, the effective nominal stress with personalized characteristics was calibrated. The personalized stress-strain curves containing individual characteristic, like diopter and anterior surface curvature, was accurately measured in this study. These results provide an experimental method using biaxial tensile test with corneal lenticules. It is the foundation for investigating the hyperelasticity and anisotropy of the central anterior stroma of human cornea.

Risk Factors for Fibrous Ingrowth in Eyes Requiring Primary Keratoplasty.

The aim of this study was to define risks for corneal transplantation associated with fibrous ingrowth among first-time transplant recipients. We performed a retrospective case-control study of patients with a histopathologic diagnosis of fibrous ingrowth between 2002 and 2019. Patients with fibrous ingrowth from a first corneal specimen were included. Those with incomplete records were excluded. A 1:2 case-control ratio was used. Controls were matched using surgical indication, surgery year, transplantation method, sex, and age. Seventy-eight eyes (76 patients) were included and matched with 160 control eyes. The incidence of fibrous ingrowth found on a first corneal transplant was 0.6% per year. The most common keratoplasty indications were pseudophakic corneal edema (n = 25, 32%) and aphakic corneal edema (n = 15, 19%). Cases were more likely to have a history of ocular trauma (odds ratio [OR], 2.94; 95% CI, 1.30-6.30; P = 0.007), uveitis (OR, 2.73; 95% CI, 1.12-6.63; P = 0.022), retinal detachment or previous retinal surgery (OR, 2.40; 95% CI, 1.34-4.30; P = 0.003), glaucoma tube-shunt surgery (OR, 2.70; 95% CI, 1.29-5.65; P = 0.007), aphakia (OR, 3.02; 95% CI, 1.61-5.67; P = 0.0004), or iris derangement (OR, 10.52; 95% CI, 5.45-20.30; P <0.0001). A multivariate logistic regression model using iris derangement, history of ocular trauma, history of uveitis, and history of cataract surgery demonstrated 81% sensitivity and 66% specificity in predicting presence of fibrous ingrowth. A history of ocular trauma, uveitis, retinal detachment or previous retinal surgery, glaucoma tube-shunt surgery, aphakia, and iris derangement are risks for detecting fibrous ingrowth among first-time keratoplasty recipients. Patients with these conditions should be monitored closely for corneal decompensation.

Investigation of microstructural failure in the human cornea through fracture tests

Fracture toughness of the human cornea is one of the critical parameters in suture-involved corneal surgeries and the development of bioengineered mimetics of the human cornea. The present article systematically studied the fracture characteristics of the human cornea to evaluate its resistance to tear in the opening (Mode-I) and trouser tear mode (Mode-III). Tear experiments reveal the dependency of the fracture behavior on the notch size and its location created in the corneal specimens. The findings indicate lamellar tear and collagen fiber pull-out as a failure mechanism in trouser tear and opening mode tests, respectively. Experimental results have shown a localized variation of tear behavior in trouser tear mode and indicated an increasing resistance to tear from the corneal center to the periphery. This article demonstrated the complications of evaluating fracture toughness in opening mode and showed that the limbus was weaker than the cornea and sclera against tearing. The overall outcomes of the present study help in designing experiments to understand the toughness of the diseased tissues, understanding the effect of the suturing location and donor placement, and creating numerical models to study parameters affecting corneal replacement surgery.

Patterns of Corneal Disorders in Corneal Button Specimens: Descriptive Study in a Tertiary Referral Hospital in Bahrain

Introduction: Corneal injuries and disorders are among the commonest clinical scenarios that are encountered in the ophthalmology clinical practice. Penetrating Keratoplasty (PKP) surgeries count for the most frequent efficient surgical management of diseased corneas. The latter are usually sent as button specimens for histopathology examination for further describing the pattern of the corneal disorders. Aims and Objectives: The aims of this study are to discuss the rate of Penetrating Keratoplasty (PKP) surgeries in SMC in 6 years interval (2016-2022) along with to determine the most common histopathological and microbiological diagnosis of corneal specimens from Penetrating Keratoplasty (PKP) and to study the clinical spectrum with age and sex distribution of corneal disorders in Bahrain alongside correlation with the comorbidities and the pathological diagnosis. Patients and Methods: It is a retrospective analysis of one-hundred and one histopathology reports of corneal button specimens at Salmaniya medical complex during the last 6 years (1-1-2016 till 31-3-2022). Medical records, surgical notes and histopathology reports of patients were retrieved from ISEHA system. Statistical analysis was done using Microsoft Excel 2019. Results: Corneal scarring (44%) was the most common pathological diagnosis, followed by Keratoconus (KC) (15%), acute keratitis (14%), degeneration (9%), chronic keratitis with fibrosis (5%), decompensated cornea and failed graft (5%), pseudophakic bullous keratopathy (3%) and herpetic keratitis (3%). There was Bahraini nationality (98%) and male preponderance (66%). The most common age group affected was 70–79 years with the median age of 51.5 year. Conclusion: Our study shows the importance of determining the most common histological diagnoses of corneal button specimens along with the correlation of the latter with the age, gender, surgical complications and systemic comorbidities. Knowing the exact pathology of the diseased cornea would assist in providing the proper post-operative management and to avoid possible elements that could promote complications.

The potential therapeutic efficacy of intravenous versus subconjunctival mesenchymal stem cells on experimentally ultraviolet-induced corneal injury in adult male albino rats.

The X-rays and the visible light are the main source of ultraviolet radiation (UVR). About 90% of ultraviolet B (UVB) is absorbed by the cornea which may promote corneal inflammation, oedema and damage of its epithelial layer. Bone marrow mesenchymal stem cells (BM-MSCs) have been demonstrated to ameliorate the injured corneal tissue and accelerate its wound healing. This study aimed to compare the healing effect of intravenous (IV) versus subconjunctival (SC) BM-MSCs on the rats' corneas subjected to UVB-irradiation. Ten rats were used as donors for BM-MSCs and the other 40 were allocated into four equal groups: group I (control group), group II (ultraviolet-irradiated group), group III (ultraviolet-irradiated + IV BM-MSCs-treated group) and group IV (ultraviolet-irradiated +SC BM-MSCs-treated group). Rats of all groups were euthanized after 3 weeks and the corneal specimens were processed for histopathological, immunohistochemical and electron microscopy assessment. Ultraviolet-irradiated group showed remarkable thinning of epithelial thickness, wide partial epithelial separation, and desquamation. Neovascularisation of the disorganised stroma and disrupted Descemet's membrane were observed. The superficial and basal epithelial cells appeared irregular and separated by wide intercellular spaces and inflammatory cells. Immunohistochemical examination showed a significant decrease in proliferating cell nuclear antigen immunoreaction. In contrast, minimal changes were observed in rats treated with BM-MSCs with more improvement associated with the subconjunctival administration compared to IV route. Local SC injection of BM-MSCs has an amazing regenerative efficacy on the corneal injury compared to the systemic IV route.

Ocular Surface Squamous Neoplasia: A 12-Month Prospective Evaluation of Incidence in Waikato, New Zealand.

Ocular surface squamous neoplasia (OSSN) has a high incidence in the southern hemisphere. This prospective study evaluated the incidence of OSSN in the Waikato region of New Zealand. All patients presenting with pterygium or conjunctival lesions in the Waikato region in 2020 were included. All surgeons in the region were asked to send all conjunctival and corneal specimens excised for histopathologic examination. The primary outcome measure was the incidence of OSSN. Eighty-eight percent of all excised specimens were sent for histopathologic examination. Of the 185 excised lesions sent for histopathological assessment, 18 (10%) were reported as OSSN. Patients were on average 69.4 years of age (standard deviation, SD = 6.9), predominantly male (78%), and of New Zealand-European ethnicity (89%). The OSSN annual incidence was 3.67/100,000/year. Histology grades included conjunctival intraepithelial neoplasia (CIN)-I (25%), CIN-II (25%), CIN-III (12.5%), carcinoma in situ (25%), and invasive squamous cell carcinoma (SCC) (12.5%). One patient with invasive SCC required exenteration. This study identified a high incidence rate of OSSN and is the first prospective study to analyze OSSN epidemiology in New Zealand.

Role of corneal biopsy in the management of infectious keratitis.

The aim of this study was to review the existing literature and investigate the role of microbiologic culture and histopathologic examination of corneal biopsies in the management of infectious keratitis. Corneal biopsy continues to be a significantly useful tool in the diagnosis and tailored management of infectious keratitis. Several techniques can be employed for tissue collection, handling and processing to optimize diagnostic yield and maximize safety, including emerging femtosecond laser-assisted biopsy. Corneal opacities represent a significant cause of global blindness, and infectious keratitis is the most common cause. Organism identification in progressive infectious keratitis is essential for proper management. However, microbiological culture alone has a high rate of false-negative results. Records from the Bascom Palmer Eye Institute were retrospectively searched for patients between 1 January 2015, and 31 December 2019, who underwent corneal biopsy, therapeutic keratoplasty or endothelial graft removal for infectious keratitis and had specimens bisected and submitted for evaluation with both microbiologic culture and histopathologic examination. Detection of bacteria, fungus and mycobacteria was not statistically different between culture and histopathology. Microbiology and histopathology are complementary methods for the identification of causative microorganisms in corneal specimens with presumed infectious keratitis.

Surveillance of Amoebic Keratitis-Causing Acanthamoebae for Potential Bacterial Endosymbionts in Ontario, Canada.

Acanthamoeba spp. are the causative pathogens of several infections, including amoebic keratitis (AK), a vision-threatening infection. Acanthamoebae from corneal specimens of patients with AK harbor bacterial endosymbionts, which may increase virulence. We sought to understand the spectrum of bacterial endosymbionts present in clinical isolates of Acanthamoeba spp. identified in our reference parasitology laboratory. Isolates of Acanthamoeba spp. obtained from our biobank of anonymized corneal scrapings were screened for potential endosymbionts by PCR using primer pairs detecting bacteria belonging to orders Chlamydiales, Rickettsiales, or Legionellales and pan16S primers. Three primer pairs specific to the 18s rRNA gene of Acanthamoeba spp. were used for the amplification of Acanthamoeba DNA used for sequencing. Sanger sequencing of all PCR products was performed, followed by BLAST analysis for species identification. We screened 26 clinical isolates of Acanthamoeba spp. for potential endosymbionts. Five isolates (19%) were found to contain bacterial DNA belonging to Legionellales. Three (11%) contained members of the Rickettsiales and Pseudomonas genticulata was detected in a Rickettsia-positive sample. One strain (4%) contained Neochlamydia hartmannellae, a member of the Chlamydiales order. Bacterial endosymbionts are prevalent in clinical strains of Acanthamoeba causing AK isolated from corneal scrapings. The demonstration of these organisms in clinical Acanthamoeba isolates supports a potential exploration of anti-endosymbiont therapeutics as an adjuvant therapy in the treatment of AK.

Presence of SARS-CoV-2 RNA in human corneal tissues donated in Italy during the COVID-19 pandemic

ObjectiveTo analyse corneal tissues from asymptomatic donors with a postmortem nasopharyngeal swab tested positive for the presence of SARS-CoV-2 RNA, and therefore, understand the role that corneal transplantation may have...

Spectrum of bacterial keratitis in North India: A retrospective analysis of six years at a tertiary care eye center.

Purpose:To analyze the pattern of bacterial pathogens causing infective keratitis and their resistance to the recommended antibiotics over six years.Methods:It was a retrospective study of 9,357 cases of bacterial keratitis from January 2015 to December 2020, at a tertiary care ophthalmic center. A total of 9,547 corneal specimens were obtained from the study subjects. Demographic details of the patients, pathogenic bacteria isolated, and their antimicrobial susceptibility were noted and analyzed.Results:Bacterial pathogens were identified in 23.52% of the specimens. The most common isolates were coagulase-negative Staphylococci (60.75%), followed by Pseudomonas aeruginosa (14.23%), Staphylococcus aureus (13.92%), gram negative bacilli of the family Enterobacterales (8.64%), Streptococcus spp. (1.72%), Acinetobacter spp. (0.13%), and other non-fermenting gram-negative bacilli (0.57%). In Staphylococci, 55–80% of isolates were resistant to erythromycin, and 40–70% to fluoroquinolones, while no resistance was observed against vancomycin. 40–60% of isolates of P. aeruginosa were resistant to cephalosporins, 40–55% to fluoroquinolones, and 30–60% to aminoglycosides. Also, 40–80% of isolates of Enterobacterales were resistant to cephalosporins, and 50–60% to fluoroquinolones. Most gram-negative isolates were susceptible to carbapenems and polymyxin B.Conclusion:To the best of our knowledge, our study is the largest compilation of microbiological profile of bacterial keratitis from North India. It highlights the current trend of the bacterial pathogens that cause infectious keratitis. Staphylococci and Pseudomonas were found to be the most common pathogens. Increased resistance was seen against some of the commonly prescribed empirical antibiotics. Such evidence is useful for restructuring the empirical prescription practices from time to time.

Measuring Human Corneal Stromal Biomechanical Properties Using Tensile Testing Combined With Optical Coherence Tomography.

Purpose: To investigate the ex vivo elastic modulus of human corneal stroma using tensile testing with optical coherence tomography (OCT) imaging and its correlation with in vivo measurements using corneal visualization Scheimpflug technology. Methods: Twenty-four corneal specimens extracted from stromal lenticules through small incision lenticule extraction were cut into strips for uniaxial tensile tests. In vivo corneal biomechanical responses were evaluated preoperatively using the corneal visualization Scheimpflug technology (CorVis ST). The correlation of the elastic modulus with clinical characteristics and dynamic corneal response parameters were analyzed using Spearman’s correlation analysis. Results: The mean low strain tangent modulus (LSTM) of the human corneal stroma was 0.204 ± 0.189 (range 0.010–0.641) MPa, and high strain tangent modulus (HSTM) 5.114 ± 1.958 (range 2.755–9.976) MPa. Both LSTM (r = 0.447, p = 0.029) and HSTM (r = 0.557, p = 0.005) were positively correlated with the stress-strain index (SSI). LSTM was also positively correlated with the A1 deflection length (r = 0.427, p = 0.037) and A1 deflection area (r = 0.441, p = 0.031). HSTM was positively correlated with spherical equivalent (r = 0.425, p = 0.038). Conclusions: The correlation of corneal elastic modulus with A1 deflection parameters and SSI may indicate a relationship between these parameters and tissue elasticity. The HSTM decreased with the degree of myopia. Combining tensile test with OCT may be a promising approach to assess corneal biomechanical properties.

Profile of Pseudomonas aeruginosa Antibiotic Sensitivity Test Results from Corneal Scrapings Specimens of Keratitis Patients with Contact Lens Users and Non-Contact Lenses Users at Dr. Soetomo Hospital Surabaya

Background: Pseudomonas aeruginosa have a significant proportion of the causes of bacterial keratitis. Corneal ulcers infected with P. aeruginosa are more severe than other bacterial corneal ulcers. P. aeruginosa is often associated with keratitis that results from wearing contact lenses, which eventually leads to corneal ulcers. This study aims to determine the differences in the results of the antibiotic sensitivity test of P. aeruginosa from corneal scraping specimens of keratitis patients using contact lenses and non-contact lens users at RSUD dr. Soetomo. Methods: This study is an observational analytic study of secondary data from corneal scraping cultures of patients with keratitis infected with P. aeruginosa at Dr. Soetomo Hospital period January 2017-December 2020. Results: The total number of samples included in the inclusion criteria was 46 samples. Of the total sample, 8 (17.40%) were contact lens users and 38 (82.60%) were non-contact lenses. The male sex and female sex each as much as 50%. The distribution of sample age categories for 0-20 years was 21.74%, 21-40 years was 13.04%, 41-60 years was 41.30%, and >60 years was 23.91%. Based on samples from 8 contact lens patients, antibiotics were found to be 100% sensitive, namely Amikacin, Cefepime, Ciprofloxacin, Imipenem, Levofloxacin, Meropenem, and Piperacillin tazobactam, Aztreonam and Gentamicin 87.5%, Ceftazidime 75%, Tobramycin 37.5% and Piperacillin 25%. Meanwhile, from a sample of 38 patients who did not wear contact lenses, the sensitive antibiotics were Cefepime 100%, Meropenem 94.8%, Amikacin 92.1% Imipenem 86.9%, Piperacillin-tazobactam 76.3%, Ciprofloxacin 73.8%, Gentamicin 73.8%, Aztreonam 68.4%, Levofloxacin 68.4%, Piperacillin 50%, Ceftazidime 44.7%, and Tobramycin 28.9%. Conclusion: The results of the antibiotic sensitivity test against P. aeruginosa from keratitis patients with a history of contact lens use showed that 8/8 (100%) of the active antibiotics were Amikacin, Cefepime, Ciprofloxacin, Imipenem, Levofloxacin, Meropenem, and Piperacillin tazobactam. Then followed by Aztreonam and Gentamicin (7/8). The results of the antibiotic sensitivity test against P. aeruginosa from keratitis patients who had no history of using contact lenses showed that the active antibiotics were above 50%, namely Cefepime 38/38 (100%), Meropenem 36/38 (94.8%), Amikacin 35 /38 (92.1%), Imipenem 33/38 (86.9%), Piperacillin-tazobactam 29/38 (76.3%), Ciprofloxacin 28/38 (73.8%), Gentamicin 28/38 (73 .8%), Aztreonam 26/38 (68.4%), and Levofloxacin 26/38 (68.4%). Keywords: Antibiotic sensitivity, Pseudomonas aeruginosa, keratitis, contact lenses

Severe marginal sterile keratitis in a patient with staphylococcal endophthalmitis after phacoemulsification

Postoperative endophthalmitis is sight-threatening, severe inflammation in posterior vitreous cavity and anterior chamber. Marginal keratitis with infiltrates or ulcers following endophthalmitis can be infectious or sterile, but the etiologies related to intraocular infection have rarely been reported. Here we present an unusual case of severe marginal keratitis with sterile infiltrates concomitant with staphylococcal endophthalmitis after phacoemulsification. Creamy white ring infiltrates at the corneolimbal junction was found with severe vitritis. With antibiotics treatment, endophthalmitis improved while the corneal infiltrates progressed. After corneal specimens yielded negative results, the corneal infiltrates improved under proper topical corticosteroid without marked sequelae. In conclusion, noninfectious, immune-related marginal sterile keratitis may develop in patients with staphylococcal endophthalmitis after phacoemulsification.