Corneal Involvement in HIV-infected Individuals.

Corneal involvement in HIV-infected individuals may be broadly classified into two categories, namely, infectious and noninfectious with the vast majority of manifestations occurring in the former. In this article, we shall focus on these two categories and strive to highlight those presentations that should alert the clinician to suspect underlying HIV infection. Infectious group mainly consists of Herpitic group of viral infections. Bacterial causes may be due to Staphylococcus epidermidis, Staphylococcus aureus, Pseudomonas aeroginosa, alpha hemolytic Streptococcus, Micrococcus and Bacillus. Fungalf keratitis in HIV-infected individuals depends on the geographic locations from which patient comes. Microsporidia and Acanthamoeba are common Protozoal causes. Non-infective inflammatory causes include peripheral ulcerative keratitis, keratoconjunctivitis sicca, and squamous cell carcinoma of the conjunctiva. Severity which is abnormally severe or very minimally reactive makes the clinician suspect of immunosuppression.

In Vitro and in Vivo Evaluation of Membrane-Active Flavone Amphiphiles: Semisynthetic Kaempferol-Derived Antimicrobials against Drug-Resistant Gram-Positive Bacteria.

Because of the rapid increase in bacterial resistance, there is an urgent need for developing new antimicrobial agents to combat multidrug-resistant pathogens. In this study, we designed and synthesized a series of kaempferol derivatives as antimicrobial agents biomimicking the structural properties and biological functions of host defense peptides. After fine-tuning of hydrophobic and cationic hydrophilic moieties linked to the flavone scaffold of kaempferol, we obtained a lead compound (52) that displayed high membrane selectivity (>128), poor hemolytic activity, low cytotoxicity to mammalian cells, and excellent activity against Gram-positive bacteria (minimum inhibitory concentrations = 1.56 µg/mL), including methicillin-resistant Staphylococcus aureus. Compound 52 can kill bacteria quickly by destroying the bacterial membranes and avoid developing bacterial resistance. Moreover, compound 52 exhibited potent in vivo antibacterial activity against S. aureus in a murine corneal infection model. These results indicated that compound 52 had the therapeutic potential as a novel membrane-active antimicrobial to combat Gram-positive bacterial infections.

Improving the Efficiency and the Technique of the Corneal Scrape Procedure via an Evidence Based Instructional Video at a Quaternary Referral Eye Hospital.

Purpose: Corneal culturing requires understanding of aseptic non-touch technique and avoidance of possible contaminants. Currently, there is no formal training in the technique and registrars are typically taught by another registrar in the emergency setting.The aim of the study was to develop an evidence-based instructional video for the corneal scrape procedure in microbial keratitis. The study then aims to assess the effect of the instructional video on clinician performance of the corneal scrape procedure.Method: An instructional video for corneal scraping was developed by identifying key steps for the procedure based on available evidence from a review of the literature and clinical practice. A prospective observational comparative case series that included clinicians at the Sydney Hospital/Sydney Eye Hospital, NSW Australia was conducted. Clinicians performing corneal scrapes had their performance of the procedure assessed prior to and after viewing the instructional video.Results: Sixteen key steps to follow in performing the corneal scrape procedure were found and demonstrated in the instructional video. Fourteen clinicians were observed performing 24 corneal scrapes in 24 patients with a median age of 56 years (IQR 34-65 years) and 45% male. Pre-video 11 scrapes were observed vs 13 scrapes post-video. Descriptive data were summarised and non-parametric categorical data analyzed using IBM SPSS (version 1.0.0.800) to perform chi-square and Wilcoxon signed-rank tests. Statistical significance was defined as p < .05. The steps of the corneal scrape procedure were performed correctly by a greater number of clinicians post-video compared to pre-video (p = .003). There was a significant improvement in inoculation of agar plates with cross-hatched streaks (92% post- vs 55% pre-video) and the maintenance of an intact agar surface (92% post vs 55% pre-video) (p = .033).Conclusion: An instructional video optimized the performance of corneal scraping, by ophthalmology trainees, in patients with microbial keratitis.

Corneal Biofilm Plaques: A Novel Clinical Presentation.

PURPOSE: To report a novel clinical presentation of corneal biofilms, consisting of formation of superficial and recurrent corneal plaques. METHODS: Interventional case report. A 9-year-old boy presented with subepithelial, whitish, avascular, and recurrent corneal plaques without any clinical manifestations of active corneal inflammation and/or infection. He had a history of minor ocular trauma; otherwise, his medical history was unremarkable. RESULTS: An excisional biopsy was performed under topical anesthesia. Histological analysis identified these plaques as clusters of gram-negative bacilli surrounded by an extracellular matrix. Samples were further evaluated with special stains (calcofluor white, Flamingo fluorescent dye, propidium iodide, and Gomori-Grocott) that demonstrated biofilm structures. CONCLUSIONS: Corneal plaques are a very rare clinical presentation of corneal biofilms that allow prolonged survival of microorganisms even in the absence of prosthetic material and clinical signs or symptoms of corneal active inflammation and/or infection.

Staphylococcus aureus alpha-hemolysin impairs corneal epithelial wound healing and promotes intracellular bacterial invasion.

Colonization by Staphylococcus aureus (S. aureus) has been implicated in many infectious and wound healing disorders. This study was performed to characterize the pathogenic role of S. aureus alpha-hemolysin (alpha-toxin) in corneal epithelial wound healing and infectious keratitis in the setting of a corneal wound. The effect of wild-type and isogenic Hla mutant (α-hemolysin gene deleted) S. aureus bacteria and conditioned media on corneal epithelial wound healing was tested in vitro using a scratch assay and in vivo using a murine epithelial debridement model. The invasiveness of wild-type and Hla mutant S. aureus was evaluated in vitro in human corneal epithelial cells and in vivo in a murine model of infectious keratitis following total epithelial debridement. S. aureus and its conditioned media significantly delayed epithelial wound closure both in vitro (P < 0.05) and in vivo (P < 0.05). The effect of S. aureus on wound healing was significantly diminished with the Hla mutant strain (P < 0.05). Likewise, compared to the wild-type strain, the Hla mutant strain demonstrated significantly reduced ability to invade corneal epithelial cells in vitro (P < 0.05) and infect murine corneas following total epithelial debridement in vivo (P < 0.05). In conclusion, S. aureus alpha-hemolysin plays a major role in the pathologic modulation of corneal epithelial wound healing and the intracellular invasion of the bacteria. Limiting colonization by S. aureus and/or blocking alpha-hemolysin may provide a therapeutic approach for corneal wound healing and infectious disorders.

Infectious crystalline keratopathy.

Infectious crystalline keratopathy was first reported by Gorovoy and colleagues in 1983 when they identified bacteria colonizing a cornea after a penetrating keratoplasty. Subsequent cases have elaborated on the organisms responsible and the management outcomes. Patients present with a white or gray branching opacity originating from an epithelial defect, commonly after a penetrating keratoplasty. Local immunosuppression contributes to the quiescent nature and the limited inflammatory response associated with infectious crystalline keratopathy. Diagnosis of the infective pathogens may be difficult, with a corneal scraping often being too superficial to obtain an adequate specimen. A biofilm is present that advantages microorganism survival, reduces antibiotic bioavailability, and inhibits diagnostic microbial detection. Treatment begins with topical antimicrobials, initially broad spectrum and then targeted to microorganism sensitivity. Adjunctive therapies to enhance the efficacy of treatment include disruption of the microorganism biofilm by laser, intrastromal antibiotics, and keratectomy. In recalcitrant cases, or where corneal scarring ensues, corneal transplantation is required.

Outcomes of Repeat Keratoplasty for Failed Therapeutic Keratoplasty.

PURPOSE: To analyze clinical outcomes of repeat optical penetrating (PK) or endothelial keratoplasty (EK) after failed therapeutic keratoplasty (TPK). DESIGN: Retrospective consecutive, comparative, interventional case series. METHODS: setting: LV Prasad Eye Institute, Hyderabad, India. STUDY POPULATION: Patients aged >18 years who underwent a repeat PK or EK following a failed TPK with a follow-up of at least 1 year were included. Patients with culture-negative ulcers, viral etiology, coexistent ocular surface disease, and multiple grafts were excluded from the study. INTERVENTION: PK or EK for failed TPK. MAIN OUTCOME MEASURE: Corrected distance visual acuity at 1 year follow-up. secondary outcome measure: Graft clarity. RESULTS: One hundred twelve eyes (67 PK, 45 EK) were included in the study. The PK group had a significantly higher number of cases with high-risk features prior to regraft. Improvement in visual acuity in each of the types of grafts was statistically significant (P < .01), but there was no difference between the 2 groups at 1 year postoperatively. A statistically significant proportion of grafts regained graft clarity after regrafting in the PK group (P < .01) but not in the EK group (P = .205) at 1 year postoperatively. Endothelial rejection rates were higher in the PK group. Subgroup analysis showed that eyes that had PK or EK for failed TPK conducted for Aspergillus keratitis showed better outcomes in terms of graft clarity. Kaplan-Maier (KM) survival analysis for graft clarity showed cumulative survival of 50% at 5 years. The survival using the KM curve was not statistically different between the 2 groups (P = .33). CONCLUSION: This study shows that visual rehabilitation with relatively good functional outcomes can be achieved by performing repeat PK or EK in patients after failed TPK.

A year of cornea in review: 2013.

PURPOSE: The goal of this study was to provide an update of significant corneal literature published in 2013. DESIGN: This study is a systematic literature review. METHODS: We conducted a systematic review of the English-language literature published from January 1, 2013, to December 31, 2013, using the following PubMed search and Medical Subject Headings terms: cornea transplantation, keratoplasty, Descemet membrane endothelial keratoplasty, Descemet stripping endothelial keratoplasty, cross linking, pre-Descemet's layer, Rho-associated kinase, keratoprosthesis, infectious keratitis, corneal dystrophy, corneal astigmatism, and keratoconus. RESULTS: This review summarizes relevant and innovative original articles, review articles, and novel techniques from the following journals: American Journal of Ophthalmology, British Journal of Ophthalmology, Cornea, Graefe's Archive for Clinical and Experimental Ophthalmology, Investigative Ophthalmology & Visual Science, JAMA Ophthalmology, Journal of Cataract and Refractive Surgery, Journal of Refractive Surgery, and Ophthalmology. Case reports, abstracts, letters to the Editor, and unpublished work were excluded, as well as articles e-published ahead of print in 2012 that were discussed in the previous review. One hundred twenty-seven articles met the criteria for this review. CONCLUSIONS: This review summarizes significant cornea-related literature from 2013.

Corneal infection by Pseudomonas stutzeri following excision of trigeminal nerve schwannoma.

A 25-year-old woman underwent intracranial surgery for trigeminal nerve schwannoma (TGNS) with persistent left-sided facial hypoaesthesia. Two months later, she developed a central corneal ulceration. Scraping of the corneal lesion revealed Gram-negative bacilli. Genus level identification was achieved using standard techniques and species level identification, revealing Pseudomonas stutzeri, was aided by a VITEK 2 compact system. Broad-spectrum fortified antibiotics were initially started followed by species-sensitive fortified antibiotics. Ocular surface toxicity developed a week later; this was managed with a non-fortified antibiotic. The epithelial defect healed in 3 weeks with subsequent corneal scar formation. Visual rehabilitation was achieved with deep anterior lamellar keratoplasty. Six months following surgery, the patient had a visual acuity of 20/40 with -1.25 170° -0.5 refractive correction and a clear graft. This case report, for the first time, highlights P. stutzeri, an aetiological agent of corneal ulcer following excision of TGNS and its successful management.

Diversity of virulence phenotypes among type III secretion negative Pseudomonas aeruginosa clinical isolates.

Pseudomonas aeruginosa is a frequent cause of acute infections. The primary virulence factor that has been linked to clinical disease is the type III secretion system, a molecular syringe that delivers effector proteins directly into host cells. Despite the importance of type III secretion in dictating clinical outcomes and promoting disease in animal models of infections, clinical isolates often do not express the type III secretion system in vitro. Here we screened 81 clinical P. aeruginosa isolates for secretion of type III secretion system substrates by western blot. Non-expressing strains were also subjected to a functional test assaying the ability to intoxicate epithelial cells in vitro, and to survive and cause disease in a murine model of corneal infection. 26 of 81 clinical isolates were found to be type III secretion negative by western blot. 17 of these 26 non-expressing strains were tested for their ability to cause epithelial cell rounding. Of these, three isolates caused epithelial cell rounding in a type III secretion system dependent manner, and one strain was cytotoxic in a T3SS-independent manner. Five T3SS-negative isolates were also tested for their ability to cause disease in a murine model of corneal infection. Of these isolates, two strains caused severe corneal disease in a T3SS-independent manner. Interestingly, one of these strains caused significant disease (inflammation) despite being cleared. Our data therefore show that P. aeruginosa clinical isolates can cause disease in a T3SS-independent manner, demonstrating the existence of novel modifiers of clinical disease.

Equine deep stromal abscesses (51 cases - 2004-2009)--Part 2: the histopathology and immunohistochemical aspect with attention to the histopathologic diagnosis, vascular response, and infectious agents.

PURPOSE: To investigate histopathologic and immunohistochemical aspects of equine deep stromal abscesses (DSA) with a focus on the histopathologic diagnosis, presumptive etiology, and the immunohistochemical expression of three angiogenesis-related factors: vascular endothelial growth factor-A (VEGF-A), pigment epithelium-derived factor (PEDF), and interleukin-1 receptor antagonist (IL-1ra). SAMPLE POPULATION: Paraffin-embedded biopsy samples from 51 DSA. The biopsies were collected from full-thickness penetrating keratoplasty or split-thickness lamellar keratoplasty surgeries at the University of Florida Veterinary Medical Center in the period from 2004 to 2009. PROCEDURE: The histopathologic and immunohistochemical findings were tested for association between each other. Prevalence calculation and test for association with qualitative data analysis was used for data evaluation. RESULTS: Fungal hyphae were found histologically in 47.1% (n = 24) of the DSA cases. Histopathologically, most fungal DSA showed suppurative keratitis (n = 34; 66.7%) and little to no stromal vascularization infiltrating the abscess (negative association, P = 0.005). All three angiogenesis-related factors were expressed to some degree in DSA tissue. A negative association between VEGF-A and PEDF when compared to the presence of fungal hyphae (P < 0.001, P = 0.023) indicated that cases positive for these two factors will most probably not have fungal hyphae present. CONCLUSION: Abnormally decreased VEGF-A expression is suggested as the reason for the slow vascularization and delayed resolution of fungal DSA, whereas PEDF and IL-ra did not seem to have any influence on the vascularization process. Clinical and histopathologic characteristics of DSA make it possible to suggest an etiology for an equine DSA with an unknown etiology.

Management of trachomatous keratopathy by automated lamellar therapeutic keratoplasty.

PURPOSE: To evaluate the efficacy of automated lamellar therapeutic keratoplasty (ALTK) for the management of anterior corneal stromal scarring caused by trachoma. METHODS: Seventeen cases of trachomatous keratopathy that were treated by ALTK were retrospectively evaluated. The main outcome measures were uncorrected visual acuity, best-corrected visual acuity (BCVA), keratometry, pachymetry, time to epithelialization, graft clarity, and complications, if any. RESULTS: The mean age of the patients was 50.3 ± 14.1 years. Five of the 17 cases had Salzmann nodular degeneration. The mean decimal BCVA was 0.06 ± 0.05 preoperatively, which improved to 0.41 ± 0.16 at 12 months, and 12 eyes (70.6%) had a postoperative BCVA of 6/18 or better. The median epithelialization time was 6 days (range, 1-38 days). Persistent epithelial defect developed in 6 eyes, and 1 eye developed graft infection. CONCLUSIONS: Anterior stromal corneal scarring caused by trachoma can be effectively treated with ALTK. However, occurrence of persistent epithelial defects may complicate the success of this surgery.

Moxifloxacin-Gelrite in situ ophthalmic gelling system against photodynamic therapy for treatment of bacterial corneal inflammation.

In this study, six in situ gelling formulations based on Gelrite were prepared and evaluated for the retained ophthalmic delivery of Moxifloxacin (Mox). The effectiveness of the best developed formula G5 was compared with photodynamic therapy (PDT), the recent expanding approach for the treatment of ophthalmologic disorders after the assessment of optimum photodynamic inactivation parameters that permit efficient pathogens eradication. It was found that, Staphylococcus aureus (S. aureus) (Gram-positive) was more susceptible to effective lethal photosensitization that reaches 93.5% reduction in viable count than Escherichia coli (E. coli) (Gramnegative) of 76.1% using 3 mg/mL Hematoporphyrin (HP), illuminated by 630 nm Light Emitting Diode (LED) at 9 J/cm(2) and incubated for 15 min. Following topical instillation of G5 to rabbits corneas, higher amount of Mox was retained in the aqueous humor up to 24 h with significant 6-fold increase in the C(max) and AUC((0-∞)) compared to vigamox commercial eye drops. After post corneal infection with S. aureus, both approaches were effectively treating the infection without causing ocular irritation or collateral damage to corneal tissue where G5 showed remarkable improvement after four days compared to seven days of PDT treatment.

[Keratomycosis in the area of Tunis: epidemiological data, diagnostic and therapeutic modalities]. / Les kératites fongiques dans la région de Tunis: caractéristiques épidémiologiques, modalités diagnostiques et thérapeutiques.

Fungal keratitis is a serious disease involving the visual prognosis. This pathology is not well known in Tunisia. The aim of our study is to determine epidemiological data and clinical and mycological characteristics of fungal keratitis in the area of Tunis (North of Tunisia) and discuss its therapeutic modalities. This is a retrospective study including 19 cases of fungal keratitis collected over a period of 11 years (January 1998-December 2008). The diagnosis of keratomycosis was based on clinical and mycological data. Mycological examination interested corneal scraping including direct examination and culture. The cases of fungal keratitis concerned 13 men and 6 women with a mean age of 48.7 years. The most common risk factors was corneal trauma (47.4%). The mean delay between the first ophthalmic signs and consultation was 17.7 days. Most frequently fungal isolated fungi were Candida albicans (6 cases), followed by Aspergillus spp (5 cases) and Fusarium spp (4 cases). All patients received topical and systemical antifungal therapy. The evolution was favourable in six cases. Three patients retained corneal scars. The surgery was necessary in 7 cases, consisting of a penetrating keratoplasty (5 cases), an enucleating (1 case) and amniotic membrane transplantation (1 case). In conclusion, despite the improvement of diagnosis and treatment of fungal keratitis, its prognosis remains pejorative. This prognosis depends on early diagnosis and choice of antifungal therapy.

Laser corneal biofilm disruption for infectious crystalline keratopathy.

Crystalline keratopathy can be successfully treated by the Nd:YAG laser. We present two cases of crystalline keratopathy managed this way. A 36-year-old female contact lens wearer presented with crystalline keratopathy following recent treatment with topical steroids and antibiotics for a corneal abscess. In this case crystalline keratopathy developed despite the intensive topical antibiotic treatment. A 55-year-old man with a history of acne rosacea, chronic myelomonocytic leukaemia, asthma and Crohn's disease presented with crystalline keratopathy following an episode of infectious keratitis. Treatment with the Nd:YAG laser to the area of involvement was instituted in both cases. Noticeable resolution occurred within days, with subsequent full recovery. No side-effects from the use of the Nd:YAG laser were noted. There have been only two cases previously reported using this treatment modality.

Isolated lepromatous conjunctivo-corneal granuloma in a cat from Italy.

OBJECTIVE: To describe a case of a conjunctivo-corneal mass in a cat associated with acid-fast bacilli. METHODS: A 2-year-old female black European Short-Hair cat, living outdoors in a suburban environment in Italy, was referred for evaluation of a nodular, vascularized mass of 2 weeks duration. The mass involved the dorsal bulbar conjunctiva at the temporal canthus of OS and invaded the sclera and cornea. Routine ophthalmic and systemic examination, serologic testing, cytology and histology of the mass were performed. Mycobacterium specific polymerase chain reaction (PCR) of variable regions 1, 2 and 3 of the 16S ribosomal RNA (rRNA) gene was also performed. RESULTS: Neutrophils, lymphocytes, macrophages and giant cells with intracytoplasmic acid-fast bacilli were seen on cytological examination. The histological examination confirmed the presence of a granulomatous lesion with acid-fast bacilli within macrophages. Bacteriological culture of the material from the lesion was negative for Mycobacterium spp. Mycobacterium 16S rRNA gene specific PCR was positive. A diagnosis of feline leprosy was made. The owners refused any treatment, and 1 year later the lesion was still present. CONCLUSIONS: Veterinary ophthalmologists should be aware of conjunctivo-corneal leproma as an unusual symptom of leprosy.

[Purulent corneal melting secondary to multidrug-resistant Fusarium oxysporum aggravated by topical corticosteroid therapy]. / Fonte purulente de la cornée secondaire à une infection à Fusarium oxysporum polyrésistant favorisée par une corticothérapie topique.

Keratomycosis is a rare sight-threatening infection of the cornea. Predisposing factors in its pathogenesis are corneal trauma, mostly of plant origin, contact lenses, and overuse of topical corticosteroids. We report a case of a 44-year-old woman, with no ophthalmologic history, who developed severe keratitis 7 days after beginning topical therapy with a corticosteroid and antibiotic. Microbiological analysis revealed Fusarium oxysporum keratitis. Despite aggressive antifungal therapy with Voriconazole and Amphotericin B, she required a penetrating keratoplasty for impending corneal perforation. A second keratoplasty was performed because of corneal-transplant rejection after 6 months. There was no recurrence of Fusarium infection.

Borrelia-associated crystalline keratopathy with intracorneal detection of Borrelia garinii by electron microscopy and polymerase chain reaction.

PURPOSE: First report of a patient with Borrelia-associated crystalline keratopathy with intracorneal evidence of Borrelia garinii by polymerase chain reaction (PCR) and electron microscopy (EM). METHODS: Report of a 67-year-old patient with medical history of recurrent iridocyclitis and arthritis presented with a bilateral, progressive, asymmetric crystalline keratopathy, which was particularly pronounced in the peripheral temporal superior cornea. After penetrating keratoplasty, crystalline keratopathy with stromal haziness recurred. Corneal regrafting was performed. The corneal specimen from the penetrating keratoplasty was examined by light and EM as well as by PCR. RESULTS: In the explanted corneal graft, as well as retrospectively in the corneal specimen from the first keratoplasty, spirochetelike bodies and fragments were detected by light and EM. Borrelia burgdorferi sensu lato DNA was demonstrated by broad-range (16S rDNA) PCR. A more precise identification as Borrelia garinii serotype 5 was possible by analyses of the flaB and ospA gene sequences. Borrelia-specific serological tests showed borderline titers in immunofluorescence and weak reaction in immunoblot, respectively. CONCLUSIONS: This case illustrates that borreliae must be considered as a cause of crystalline keratopathy; Borrelia-specific serological tests can be false negative; explanted cornea specimens of etiologically unclear crystalline keratopathy should be analyzed by EM or PCR for detection of pathogens; and prolonged antibiotic treatment might be effective to prevent progression or recurrence of the disease.