Current diagnostic tools and management modalities of Nocardia keratitis

Nocardia species are an uncommon but important cause of keratitis. The purpose of this review is to discus previous published papers relation to the epidemiology, etiology, diagnosis and management of Nocardia keratitis. Nocardia asteroides is the most frequently reported from Nocardia keratitis. Pain, photophobia, blepharospasm and lid swelling are mainly clinical manifestations. Usual risk factors for Nocardia keratitis are trauma, surgery, corticosteroids, and contact lens wear. Several antibiotics were used for treatment of Nocardia infection but according to studies, topical amikacin is the drug of choice for Nocardia keratitis. Topical steroid should not prescribe in these patients. In conclusion, although Nocardia keratitis is rare, early diagnosis and treatment are essential to prevent any scar formation and preserve a good visual acuity.

A ten-year report of microbial keratitis in pediatric population under five years in a tertiary eye center

Purpose

To report characteristics of microbial keratitis in pediatric patients under five years.

Methods

Patients with infectious keratitis under the age of 5 years were included in this retrospective cross-sectional study for ten years. All patients were admitted and corneal scraping was performed in 81 children. Fortified empiric antibiotic eye drops including cefazolin (50 mg/cc) and amikacin (20 mg/cc) were started and the antibiotic regimen was continued or changed according to culture results. In the case of fungal keratitis, topical voriconazole (10 mg/cc) or natamycin (50 mg/cc) and topical chloramphenicol (5 mg/cc) were started. A tectonic procedure was done when corneal thinning or perforation was present.

Results

Ninety-Three Patients between 1 to 60 months with a mean age of 33 ± 18 months old with corneal ulcer were included in the study. The most common risk factor was trauma (40.9%) followed by contact lens use (8.6%). Cultures were negative for microbial growth in 28 (30.1%) patients. The most common pathogens were S. epidermidis (10.8%) and P. aeruginosa (10.8%). Fluoroquinolone antibiotics (ciprofloxacin; 93.8% sensitivity) were the most potent antibiotic against bacterial pathogens. Forty-one patients underwent tectonic procedures, which the most common ones were cyanoacrylate glue 18.3% followed by keratoplasty 16.1%.

Conclusion

This study emphasizes the role of trauma as the primary cause and S. epidermidis as the most frequent microorganism in pediatric keratitis; according to antibiogram results and poor cooperation of patients under five years, monotherapy with fluoroquinolones could be a good regimen in small non-central lesions without thinning.

The role of fungi in fungal keratitis

Fungal keratitis (FK) accounts for approximately half of the microbial keratitis encountered in low middle income countries (LMICs) and predominantly affect the working rural-poor. FK causes significant morbidity with the majority of patients left with moderate or worse visual impairment and approximately 25% requiring expensive and often unsuccessful surgical interventions. The severity of FK and the resultant corneal damage or resolution can be attributed to i) the virulence and bioburden of the fungal pathogen, ii) the host defense mechanism and immune response and iii) sub-optimal diagnostics and anti-fungal treatment strategies. This review provides a comprehensive overview of the multifaceted components that drive FK progression and resolution, highlighting where knowledge gaps exist and areas that warrant further research.

The biology of Acanthamoeba keratitis

Acanthamoeba keratitis (AK) is a rare protozoal infection of the cornea. At least eight species of Acanthamoeba are known to cause this sight-threatening disease of the ocular surface. Acanthamoeba spp. exist in a wide array of niches ranging from thermal springs to under ice and every conceivable habitat in between. Contact lens wear is the leading risk factor for AK and is practiced by over 30 million individuals in the United States, yet the incidence of AK is less than 33 cases per one million contact lens wearers. Serological studies have reported that 90%-100% of individuals with no history of AK possess antibodies specific for Acanthamoeba antigens indicating that exposure to this organism is commonplace, yet disease is remarkably rare. Animal studies have shed light on the pathobiology and immunobiology of AK and indicate that a constellation of factors including the ocular surface microbiome and the microbiome of Acanthamoeba itself contribute to the pathogenesis of AK. Interesting, secretory antibodies produced by the adaptive immune response can prevent the initiation of corneal infection, but once Acanthamoeba trophozoites breach the corneal epithelium the adaptive immune system is helpless in altering the course of AK. It has been almost 50 years since AK was first described, yet many questions remain unanswered about this curious and enigmatic disease of the ocular surface.

Incidence and outcome of transplantation of fungal-culture-positive donor corneoscleral tissue in optical keratoplasty

PURPOSE

This study aims to determine the incidence of fungal-culture-positive corneoscleral donor rim in patients undergoing keratoplasty and evaluate clinical outcomes of eyes that received these contaminated donor tissues.

METHODS

Patients who had optical keratoplasty between 2006 and 2016 and were found to have fungal-culture-positive donor rim were included. Microbiological and eye bank records were reviewed to determine the incidence of positive fungal rim cultures. Data were collected on visual and clinical outcomes. The main outcome measures were fungal-culture-positive donor rim and development of fungal keratitis or endophthalmitis post keratoplasty. Long-term clinical outcome and associated complications were the secondary outcome measures.

RESULTS

Out of 9620 cases of corneal transplants, 145 (1.5%) had fungal-culture-positive donor rim. Candida was the most common organism, cultured in 127 (87.6%) cases. There were no cases of postoperative fungal keratitis or endophthalmitis. Median follow-up was 4.8 years (interquartile range 3.8-7.2 years). Only eight cases (5.5%) received prophylactic antifungal treatment. There were 34 (23.4%) cases of rejection, 13 (8.9%) developed glaucoma, and 7 (4.8%) developed late bacterial keratitis. At last follow-up, best corrected visual acuity was 20/60 or better in 88 cases (60.7%) and 115 eyes (79.3%) had a clear graft.

CONCLUSION

The incidence of fungal-culture-positive donor rim is extremely low. The risk of developing fungal keratitis or endophthalmitis in patients who received contaminated donor tissue was almost negligible. Further studies are warranted to prove whether prophylaxis or adding amphotericin B in Optisol-GS confers any added benefit.

[Ocular manifestations of viral diseases]

Les infections virales peuvent toucher l’ensemble des tuniques oculaires et mettre en jeu la fonction visuelle à plus ou moins courte terme. Les kératites et kérato-uvéites liées au virus HSV-1 sont les atteintes les plus fréquentes. Les récurrences entraînent une opacification cornéenne irréversible qui en fait la première cause de cécité d’origine infectieuse dans les pays occidentaux, et justifient un traitement antiviral préventif au long cours. Le zona ophtalmique (10 à 20 % des zonas), peut s’accompagner d’atteintes oculaires sévères (kératites, kérato-uvéites), dont 30 % deviennent chroniques/récurrentes, et de douleurs post-zostériennes, redoutables dans le territoire trigéminé. Les rétinites nécrosantes liées aux herpesvirus (HSV, VZV, CMV), sont rares mais constituent des urgences fonctionnelles absolues nécessitant un traitement antiviral par voie intraveineuse et intravitréenne. Les conjonctivites à adénovirus constituent la première cause de conjonctivite infectieuse. Le plus souvent bénignes, elles sont extrêmement contagieuses et peuvent se compliquer de lésions cornéennes invalidantes persistant plusieurs mois, voire années. Certaines arboviroses s’accompagnent de manifestations oculaires inflammatoires. Dans le cas du Zika, les infections congénitales peuvent se compliquer d’atrophie maculaire et/ou optique. Les conjonctivites sont très fréquentes à la phase aiguë de la maladie à virus Ebola, dont 15 % des survivants présentent des atteintes inflammatoires chroniques sévères liées à la persistance du virus dans les tissus uvéaux. Enfin, dans le cadre de la COVID-19, les conjonctivites ne sont pas très fréquentes mais peuvent être inaugurales, voire au premier plan et sont associées à une excrétion virale lacrymale qui doit faire prendre toutes les précautions.

In-vitro assessment of first-line antifungal drugs against Aspergillus spp. caused human keratomycoses

BACKGROUND AND OBJECTIVES

Aspergillus keratitis are in the increasing trend and reported as the second most common cause of mycotic keratitis in developing countries. The present study was designed to isolate, identify Aspergillus spp. from the keratits/corneal ulcer patients attending a tertiary care eye hospital, Coimbatore, South India and to assess the minimum inhibitory concentrations (MICs) against ten clinically used first-line antifungal drugs.

METHODS

A total of seventy-three Aspergillus strains isolated from corneal scrapings were included and assessed for a period of one year. All isolates were identified up to the species level by morphological observations. Antifungal drug susceptibilities were determined against a standard panel of antifungal agents.

CONCLUSIONS

Five different species of aspergilli, A. flavus (n=53), A. fumigatus (n=14), A. terreus (n=9), A. tamarii (n=6) and A. niger (n=3) were identified based on morphological features. Minimum inhibitory concentration analyses indicated that, voriconazole, natamycin, itraconazole, clotrimazole, econazole followed by ketoconazole shall be the order of choices for the effective treatment for Aspergillus keratitis.

Linezolid shows high safety and efficacy in the treatment of Pythium insidiosum keratitis in a rabbit model

Efficacy and safety of three antibiotics (Linezolid-LZ, 0.2%; Azithromycin-AZ, 1%; Tigecycline-TG, 1%) were determined in the treatment of Pythium insidiosum keratitis in rabbits. Infection of right eye of 38 rabbits was induced by standard intracorneal injection of P. insidiosum zoospores (left eye, intracorneal saline). Corneal infection developed in all right eyes. One hourly eye drops of one of the three antibiotics was instilled in both eyes (3 groups of 12 rabbits each) except in controls. Half of the rabbits in each group received intracorneal injection of the respective antibiotic after 4 days of starting eye drops. Clinical scoring of eyes was done over next 3 weeks. The reduction in scores post-treatment was significant for each drug (LZ: p < 0.025, AZ: p < 0.025, TG: p < 0.01). Scores with LZ (median change of 3) was significantly (p = 0.013) higher than TG (median change of 2) and comparable (p = 0.06) to AZ (median change of 3). Reduction in clinical scores in eyes receiving intracorneal antibiotics was not significantly different from the eyes that did not receive intracorneal antibiotics (p = 0.73). While no adverse effect of LZ was seen in the control corneas, 66-100% of rabbits showed reaction to AZ and TG. Histopathology showed severe inflammation in all infected corneas and intraocular extension in some of the rabbits with poor response. The success rate was noted to be 16.7%, 25% and 50% in AZ, TG and LZ respectively (p = 0.45). LZ demonstrated superior efficacy and safety and can be considered for trial in human disease.

Aspergillus niger lectin elicits MyD88 dependent proliferation and apoptosis at lower and higher doses in immortalized human corneal epithelial cells leading to pathogenesis

An L-fucose lectin, ANL from the corneal smears of a mycotic keratitis patient was reported earlier. Interaction of ANL with immortalized Human Corneal Epithelial Cells (HCECs) was studied in order to assign the role of ANL in pathogenesis. ANL showed strong binding to HCECs which could be blocked by L-fucose and mucin. At concentrations below 0.6 μg/mL ANL showed proliferative effect and highest at 0.07 μg/mL leading to expression of proinflammatory cytokines IL-6 and IL-8. ANL induced proinflammatory response is mediated by TLR-2,-4, MyD88, NFkB and C-Jun dependent signaling. In contrast, ANL at concentrations above 0.6 μg/mL showed growth inhibitory effect at 48 h with an IC₅₀ of 2.75 μg/mL. Western blot analysis revealed that HCECs treated with ANL at lower concentration induced the expression of proinflammatory signaling proteins TLR-2, 4, MyD88, NFkB and C-Jun which maintain high cell proliferating state. At higher concentration ANL induced apoptotic effect in HCECs with an increase in early apoptotic population as demonstrated by Annexin V-PI assay. ANL induced the expression of apoptotic proteins FADD, Caspase 8 and -3 mediated by MyD88. These findings demonstrate implication of ANL in pathogenesis and the findings are of clinical significance in developing strategy for controlling the infection leading to mycotic keratitis.

Limbal stem cell deficiency secondary to systemic paclitaxel (Taxol) for breast cancer: a case report

BACKGROUND

Paclitaxel (PTX) is an antineoplastic drug widely used in treatments for ovarian, breast, and small-cell lung cancer. Although ocular effects associated with PTX have been previously described, very few studies have specifically reported systemic PTX as a contributing factor for limbal stem cell deficiency (LSCD), which is characterized by the loss of stem cell and barrier function of the limbus leading to progressive pain and reduction in visual acuity. Described here is a unique case where a patient was diagnosed with LSCD secondary to PTX use for the treatment of breast cancer, at doses of PTX far lower than what is reported in current literature.

CASE PRESENTATION

A 73-year-old woman with a previous diagnosis of breast cancer with liver metastasis presented with a complaint of increasing pain in the left eye more than the right, along with decreasing visual acuity in both eyes following 3 months of PTX therapy for recurrent liver metastases. Upon examination, best-corrected visual acuity was 20/100 in the right eye and counting fingers on the left. Peripheral neovascularization, stromal scarring, and features of limbal stem cell deficiency (LSCD) were noted on the right cornea. A central neurotrophic ulcer with thinning to 50% and 360 degrees of conjunctivalization were noted on the left. After the discontinuation PTX with doxorubicin as the substitute, there was no further progression of her LSCD, and stabilization of her ocular surface was achieved.

CONCLUSION

Although chemotherapy induced LSCD is a relatively rare adverse event, it is essential for clinicians starting new chemotherapy agents to consider the potential ocular toxicities that may result in their use. Ophthalmology review is recommended for patients after starting PTX therapy to assess for signs of LSCD, particularly in patients where drug toxicity can be aggravated due to impaired hepatic function.

Bilateral non-resolving punctate keratitis in a keratoplasty patient

This study aimed to report a case of non-resolving bilateral coarse punctate keratitis in a patient with prior bilateral penetrating keratoplasty. In view of non-response to antivirals, corneal epithelial scraping was carried out, which revealed the presence of microsporidial cysts. The infection resolved after a period of 12 days following the diagnosis, during which steroids were discontinued. Microsporidial keratitis needs to be considered in non-resolving coarse punctate keratitis and microbiologic evaluation is essential to establish the diagnosis.

Mycobacterium haemophilum scleritis: two case reports and review of literature

Background

Mycobacterium haemophilum is a rare and emerging nontuberculous mycobacteria (NTM). It normally causes localized or disseminated systemic diseases, particularly skin infections and arthritis in severely immunocompromised patients. There have been 5 cases of M. haemophilum ocular infections reported in the literature. Only 1 case presented with scleritis with keratitis. Here, we reported 2 cases of M. haemophilum scleritis. One of them was immunocompetent host and had keratitis with radial keratoneuritis as a presenting sign.

Case presentation

Case 1: A 52-year-old Thai female with rheumatoid arthritis presented with scleritis. Conjunctival scraping was carried out and the culture result was positive for M. haemophilum. Despite receiving systemic and topical antibiotics, her clinical symptoms and signs worsened. Surgical debridement was performed. After surgery, the lesion was significantly improved and finally turned to conjunctival scarring. Case 2: A 32-year old healthy Thai male without underlying disease presented with nodular scleritis and keratouveitis with multiple radial keratoneuritis. Surgical debridement of the scleral nodule was performed. Initial microbiological investigations were negative. Herpes ocular infections was suspected. Topical antibiotics, oral acyclovir, low-dose topical steroids and systemic steroids were started. The scleral inflammation subsided but later the keratitis relapsed, requiring corneal biopsy. Histopathology of the specimen revealed acid-fast bacteria and M. haemophilum was identified by polymerase chain reaction (PCR) and sequencing. The diagnosis of Mycobacterial keratitis was made. Although using the combination of systemic and topical antibiotics, his clinical status progressively deteriorated. Multiple therapeutic penetrating keratoplasties were required to eradicate the infection. No recurrence was found during the 1-year follow-up in both cases.

Conclusions

M. haemophilum can cause scleritis and keratitis, even in immunocompenent host. Radial keraoneuritis is first described in M. haemophilum keratitis. NTM keratitis should be considered in the differential diagnosis of patients with radial keratoneuritis. Increased awareness and early diagnosis using appropriate culture conditions and molecular techniques are important for the proper treatment of this infection. Prompt surgical intervention appears to be vital for successful management of M. haemophilum scleritis and keratitis.

Mammalian Ste20-like kinase 4 inhibits the inflammatory response in Aspergillus fumigatus keratitis

Mammalian Ste20-like kinase 4 (MST4), a new member of the germinal-center kinase STE20 family, was recently demonstrated to be a negative regulator of inflammation. However, whether MST4 participates in the inflammatory response to fungal infection remains unknown. Our study investigated the role and molecular mechanisms of MST4 in mice cornea and corneal epithelial cells exposed to Aspergillus fumigatus (A. fumigatus). Protein level of MST4 was detected in mice corneas and human corneal epithelial cells (HCECs) by Western blot analysis. The MST4 protein level was significantly elevated in mice corneas infected with A. fumigatus and HCECs exposed to A. fumigatus. MST4 expression was also detected in mice corneas by immunofluorescence staining. Furthermore, we found recombinant MST4 inhibited proinflammatory cytokines expressions induced by A. fumigatus at both the mRNA and protein levels in mice corneas and HCECs. To further investigate the mechanism of MST4's anti-inflammatory effect in A. fumigatus keratitis, we verified recombinant MST4 can inhibit curdlan-mediated proinflammatory cytokines production in HCECs. Surprisingly, recombinant MST4 protein downregulated A. fumigatus-induced Dectin-1 expression in both mRNA and protein levels in mice corneas. Recombinant MST4 can inhibit the mRNA expression level of Dectin-1 which was induced by curdlan in HCECs. MST4 can also inhibit the expression of Dectin-1 in mRNA levels increased by Dectin-1 overexpression plasmid in HCECs. Moreover, A. fumigatus or curdlan significantly induced the phosphorylation of Syk, which was consequently suppressed by recombinant MST4. Finally, recombinant MST4 promotes HCECs proliferation, which contribute to cornea wound healing. Taken together, our results provide evidences that MST4 inhibits inflammatory signaling response in A. fumigatus keratitis by downregulating Dectin-1/p-Syk pathway and simultaneously promotes HCECs proliferation.

Fusarium infection alters the m6A-modified transcript landscape in the cornea

N6-methyladenosine (m⁶A) is the most common post-transcriptional modification of RNA in eukaryotes that regulates the post-transcriptional expression level of genes without changing the base sequence. The role of m⁶A in fungal keratitis has not yet been elucidated. Here, we aimed to identify m⁶A modification changes and their potential roles in fungal keratitis. The murine model of fungal keratitis was established by inoculating mice with Fusarium solani (F. solani). The overall m⁶A level was detected via an m⁶A RNA methylation assay kit. The expression levels of key m⁶A modification-related genes were estimated by quantitative real-time polymerase chain reaction (PCR). The expression and localization of METTL (methyltransferase like)3, the key component of the m⁶A methyltransferase complex, was determined by immunostaining and Western blotting (WB). Immunoprecipitation methylation microarray was used to describe the changes in m⁶A modification in F. solani-infected corneal tissue. The overall m⁶A level in corneal tissue on the 5th day in the F. solani-treated group was upregulated compared with that in the control group. The demethylase levels were unaltered, but the level of the methylase METTL3 was increased significantly after fungal infection. Additionally, differences were found in m⁶A modifications in 1137 mRNAs, of which 780 were hypermethylated and 357 were hypomethylated. To the best of our knowledge, the present work is the first investigation on the m⁶A modification profiles in experimental fungal keratitis, and it may provide a potential therapeutic target.

Infectious endophthalmitis at a Philippine tertiary hospital: a ten-year retrospective study

Background

Endophthalmitis is a sight-threatening disease characterized by marked progressive inflammation of the vitreous and/or aqueous humors. Limited information is currently available regarding endophthalmitis in the Philippines. This study aimed to provide long-term summary data on endophthalmitis cases seen at the largest tertiary referral hospital in the Philippines.

Methods

All endophthalmitis cases diagnosed at the Philippine General Hospital from January 1, 2007 to December 31, 2016 were retrieved and classified by etiology. Data pertaining to history, associated risk factors, isolated microorganisms, management, and final visual outcomes for each patient were reviewed.

Results

A total of 202 cases diagnosed within the audit period were included in the study. These were classified as post-traumatic (55.94%), endogenous (14.36%), acute post-operative (10.40%), keratitis-induced (6.93%), chronic post-operative (5.44%), bleb-associated (3.96%), and suture-associated (2.97%) endophthalmitis. Males comprised 71.29% of the population, while the largest age group affected was 0–10 years (24.75%). The culture-positive rate was 57.89%. The predominant etiology was Gram-positive bacteria (38.18%), followed by Gram-negative bacteria and mixed pathogens (21.82% each), and fungi (18.18%). The most common organisms were Streptococcus, Staphylococcus, Pseudomonas, Aspergillus, and Candida, accounting for 56.45% of isolates. Pars plana vitrectomy was done for 62.87% of patients, intravitreal and other antibiotic therapy in 23.27%, and primary enucleation/evisceration in 10.89%. The final outcomes and best corrected visual acuities were: anophthalmia 11.86%, no light perception/no dazzle 27.84%, light perception 8.76%, hand motions 24.23%, counting fingers 5.15%, 3/200 to 20/50 12.89%, and 20/40 to 20/20 9.28%.

Conclusions

There was a higher proportion of post-traumatic endophthalmitis cases compared to traditional estimates but consistent with studies from China and Thailand. The majority of these cases involved younger children as well as young to middle-aged males engaged in carpentry and construction work, implying a need for increased public health awareness and strengthening of childcare and workplace safety policies. Our microbiologic profile showed a lower proportion of Gram-positive infections and a higher proportion of mixed pathogen infections compared to other studies. There was also a higher proportion of fungi associated with post-operative and keratitis-induced endophthalmitis. The best outcomes were seen in acute post-operative and bleb-associated endophthalmitis, and the worst outcomes in endogenous and keratitis-induced endophthalmitis. Visual outcomes were poorer compared to other Western and Asian countries, with only 21.7% of patients improving from presentation.

Delhi Infectious Keratitis Study: Update on Clinico-Microbiological Profile and Outcomes of Infectious Keratitis

Purpose:

To study the clinico-microbiological profile and outcomes of infectious keratitis (IK) at a tertiary eye care center in North India.

Methods:

This is a retrospective, hospital-based, cross-sectional study. One thousand seven hundred and eighty-six corneal microbiological reports were identified from January 2017 to December 2018, out of which 625 patients of IK fulfilled the inclusion criteria. They underwent microbiological examination which included corneal scrapings, culture, and antibiotic sensitivity. Demographic features, signs and symptoms, risk factors such as associated trauma, previous ocular surgery, and use of corticosteroids were also recorded.

Results:

Of the 625 patients, 68.2% were male and 31.8% were female. The age group affected most was the sixth decade; 21.9% (137 cases). Trauma was the most common associated risk factor in 151 cases (24.2%) followed by previous ocular surgery in 111 (17.8%). Out of the 625 corneal scrapings, 393 (62.9%) were culture-positive. Bacterial culture accounted for 60.6% (238/393) and fungal cultures were 143 (36.4%). More than 50% of the bacterial keratitis cases and more than 60% of the fungal cases had a favorable outcome. Staphylococcus sp. and Fusarium sp. were the most common bacteria and fungus isolated, respectively. Only one-third of the cases required surgical intervention, and the remaining two-thirds were managed medically.

Conclusions:

In the current study, cultures were positive in 63% of cases, and the majority of cases had bacterial growth. Surgical intervention was needed in one-third of the cases. Management of corneal infections is incomplete without a good microbiological workup. Ophthalmologists should be encouraged to learn and practice basic staining procedures, and this should start early in the training years.

Toll-like receptor gene polymorphisms in patients with keratitis

OBJECTIVE

To investigate differences in SNPs in TLR genes between people who had keratitis and controls in an Indian population.

METHODS

145 cases of keratitis and 189 matched controls were recruited. DNA was extracted from peripheral blood. Single nucleotide polymorphisms (SNP) in TLR2 (n = 6), TLR4 (n = 15), TLR5 (n = 13) and TLR9 (n = 10) were analysed. The risk of developing keratitis was assessed based on allele, genotype and haplotype associations.

RESULTS

For all cases of keratitis, the TLR4 SNP rs4986791 TC genotype frequency was significantly higher in cases (p = 0.006, OR = 1.96, 95 % CI 1.19-3.2). Including cases of only microbial keratitis (MK) revealed that genotypes in TLR2 SNP rs5743706 TA (p = 0.0001; OR = 8.61; 95 % CI 2.59-28.56)), TLR4 SNP s4986791 TC (p = 0.002; OR = 2.65; 95 % CI 1.39-5.07) were significantly more common for MK, whereas the TLR5 SNP rs2241096 A allele (p = 0.00316, OR = 0.42, 95 % CI 0.2-0.9286) and GA genotype (p = 0.016; OR = 0.45; 95 % CI 0.23-0.86) was significantly less common in MK cases. The TLR2 SNP rs5743706 genotype TA was significantly less common in the sterile keratitis (SK) group (p = 0.004, OR = 0.43, 95 %CI 0.24-0.77). Haplotype analysis of MK compared to controls showed that TLR2 AT was more common in controls (p = 0.003); TLR4 ACAC was more common in cases (p = 0.004); TLR5 TGGCA was more common in controls (p = 0.001).

CONCLUSION

The present study revealed multiple associations between variants across TLR genes, which may have implications for understanding the underlying host factors, risk of developing keratitis and molecular pathogenesis in keratitis.

Rapid, non-invasive screening of keratitis based on Raman spectroscopy combined with multivariate statistical analysis

This study proposes a multivariate statistical analysis method based on Raman spectroscopy and different dimensionality reduction methods combined with the support vector machine (SVM) algorithm for rapid, non-invasive, high-accuracy classification of keratitis screenings. In this experiment, tear samples from 19 subjects with keratitis and 27 healthy subjects were detected, Raman spectra of the two groups of subjects were compared and analysed, and we found that their spectral intensities were different at 1005 cm^-1 and 1155 cm^-1 Principal component analysis (PCA) and partial least squares (PLS) were used for feature extraction, which greatly reduced the dimensionality of the high-dimensional spectral data. Then, the above two feature extraction methods were used as input to an SVM to build the discriminant diagnosis model. The average accuracy obtained from the PCA-SVM and PLS-SVM models was 77.86 % and 100 %, respectively. Our results suggest that tear Raman spectroscopy combined with multivariate statistical analysis has great potential in screening for keratitis. We expect this technology to could lead to the development of a portable, non-invasive and highly accurate keratitis screening device.

Face Mask-Associated Ocular Irritation and Dryness

During the current coronavirus disease 2019 (COVID-19) epidemic, the concern for reducing disease transmission has led to a worldwide increase in face mask utilization. During this period, we have observed a corresponding increase in ocular irritation and dryness among regular mask users. This finding has not been previously described in the literature but has important implications on eye health and infection prevention, as mask use is likely to continue for the foreseeable future.

First report of a new corneal pathogen: Phaeoacremonium parasiticum

Keratitis is a public health issue in developing countries and a potentially sight-threatening condition. Collagen fibrils in the corneal stroma are parallels to each other. Fundamental substance maintains the same space between collagen fibrils. That is how corneal transparency can be achieved. Any damage which can modify this structure will lead to corneal opacity and loss of vision. Fungal keratitis might appear in up to one-third of cases. Nevertheless, fungal keratitis remains poorly described and understood. Herein, we present the first ever reported case of corneal infection due to Phaeoacremonium parasiticum in a young patient. We describe the clinical and microbial characteristics, and we also discuss the use of confocal microscopy in early diagnosis of this infection.

[Quantitative evaluation of infectious keratitis by anterior segment optical coherence tomography]

The clinical evaluation of infectious keratitis takes place largely through biomicroscopic examination, which presents limitations in the evaluation of the depth of the infiltrate and the exact thickness of the cornea, whether edematous or thinned. In this study, we aim to quantify the human corneal inflammatory response in treated infectious keratitis by anterior segment optical coherence tomography (AS-OCT). Patients with infectious keratitis were recruited prospectively in the ophthalmology department of the military hospital of Rabat between November 2017 and May 2019. Over the study period, 32 patients were included. A standardized scanning protocol was used. The thickness of the infiltrate, when present, and corneal thickness in any area of thinning and any surrounding edematous areas were measured. The various thicknesses gradually decreased over the course of follow-up, providing objective evidence of therapeutic efficacy in the early stages. Improvement in corneal edema and thinning was faster in the early stage. AS-OCT scanning can be used along with slit lamp examination to quantify and objectively follow infectious keratitis.

Genotyping and phylogenic study of Acanthamoeba isolates from human keratitis and swimming pool water samples in Iran

Objective

Acanthamoeba keratitis cause severe corneal infection and lead to poor vision and blindness. This disease is caused by a unicellular amphizoic protozoon called Acanthamoeba spp. that present in different environments. This study aimed to represent the existence and genotyping of Acanthamoeba spp. in patients with keratitis and swimming pool water (SPW) in Tehran Province, Central Iran.

Methods

In this descriptive study, 56 clinical samples were collected from patients with keratitis and 30 water samples were collected from different swimming pools in Tehran Province. All samples were examined based on the morphological and molecular techniques. The genotypes were determined by sequencing the partial of 18S rRNA gene.

Results

Of 56 clinical (corneal) and 30 environmental (SPW) samples, 30.3% and 40.0% were positive for Acanthamoeba spp., respectively. According to sequencing analysis, 94.1% of amoebic keratitis isolates were belonged to T4 genotype and only one (5.8%) isolate was belonged to T11 genotype. All genotypes were detected from SPW samples were identified as T4 genotype.

Conclusion

According to our results, use of contact lens and swimming in pool poses the major risk factor for amoebic keratitis in the studied area (Tehran). Moreover, T4 genotype was the predominant genotype of human keratitis and swimming pool samples there. Consequently, essential and practical measures are urgently needed to prevent subjects against this ocular seriously disease.

Fusarium infections: Epidemiological aspects over 10 years in a university hospital in France

BACKGROUND

Fusarium is an environmental mold that causes deep or superficial mycosis in immunocompromised or immunocompetent patients respectively.

METHODS

This epidemiological study evaluated the frequency of Fusarium infections in our university hospital center in France over a decade from 2007 to 2016 and its representativeness in the main clinical infections.

RESULTS

A total of 715 Fusarium sp. were isolated from various sampling sites. Fusarium was detected in 0.47% of blood cultures, 31.1% of ophthalmic samples, and 8.48% of nail samples. The frequency of Fusarium infections was stable over this decade.

CONCLUSIONS

The main Fusarium species complexes recorded in this study were Fusarium oxysporum species complex and Fusarium solani species complex, indicating the importance of Fusarium as a fungal agent that should be considered in clinical practice. A focus on invasive fusarioses shows that they all occur in hematology patients.

Delay in Diagnosis of Two Siblings with Severe Ocular Problems and Autoimmune Polyglandular Syndrome

Autoimmune polyendocrine syndrome type 1 (APS1) is a scarce polyendocrinopathy with autosomal recessive inheritance results from defects in the human autoimmune regulatory (AIRE) gene. In addition to three major manifestations of APS1 including mucocutaneous candidiasis, hypoparathyroidism, and Addison's disease, ophthalmic problems such as keratoconjunctivitis, dry eye, iridocyclitis, and cataract can be seen in these patients. In this article, we introduced two siblings presented with nail dystrophia, severe photophobia, and keratitis since early childhood which genetic examination revealed single nucleotide T>C translocation in their 2nd exon and heterozygous deletion mutation in their 12th exon.

Phylogenetic Analysis of Clinically Relevant Fusarium Species in Iran

Fungi of the genus Fusarium are well known as major plant pathogens but also cause a broad spectrum of human infections. Sixty-three clinical isolates, collected during 2014-2017, were identified using a part of the TEF1 gene as barcoding marker. Fusarium fujikuroi species complex (FFSC, n = 41, 65%) showed to be the dominant etiological agent, followed by F. solani species complex (FSSC, n = 14, 22%) and F. oxysporum species complex (FOSC, n = 7, 11%). There was one strain belonging to F. lateritium species complex (FLSC, n = 1, 1.5%). For final identification, a phylogenetic tree was constructed including the type strains of each species complex. Most cases of fusariosis were due to nail infection (n = 38, 60.3%), followed by keratitis (n = 22, 34%). Fusarium infections are difficult to be treated due to their intrinsic resistance to different azoles; however, accurate and fast identification of etiological agents may enhance management of the infection. We present the first phylogenetic study on clinical Fusarium spp. from Iran.