SciCombinator

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Concept: Keratitis

27

To review an Acanthamoeba keratitis case series for the documented extracorneal spread of the amoeba.

Concepts: Keratitis, Amoeba, Amoebozoa, Amoeboid, Acanthamoeba

27

To report the observation of prolonged reepithelialization after photorefractive keratectomy (PRK) associated with the use of besifloxacin 0.6% (Besivance; Bausch & Lomb, Rochester, NY) underneath bandage contact lenses (BCLs) placed during surgery.

Concepts: Mount Hope Cemetery, Rochester, Bausch & Lomb Place, Cornea, Keratitis, Photorefractive keratectomy, Rochester, New York, Bausch & Lomb, Contact lens

27

Mini-scleral lenses are an increasingly popular contact lens modality; however, there are relatively few reports regarding the unique aspects of their fitting and potential complications. We report a complication of mini-scleral lens wear in a 44-year-old female patient using the lenses for keratoconus. Her mini-scleral contact lenses were non-fenestrated and fitted to vault over the cornea and seal at the periphery. The patient presented with an acute red eye (non-ulcerative keratitis), characterised by unilateral severe conjunctival and limbal hyperaemia, corneal infiltration and pain. Refitting the lens to increase the corneal vault clearance did not prevent recurrence of the keratitis, some five months later. Successful prevention of further episodes of the acute red eye was achieved through improved patient compliance with lens cleaning, disinfection and lens case procedures. Lens hygiene may be particularly important for mini-scleral lenses with a sealed fitting.

Concepts: Keratoconus, Lens, Orthokeratology, Contact lenses, Eye, Keratitis, Cornea, Contact lens

25

A 76 year old male presents with a corneal perforation in a phthisical eye. Definitive treatment in the form of an evisceration was delayed by 38 days. During this period a bandage contact lens prevented extrusion of ocular contents through an enlarging corneal perforation. This case demonstrates that a bandage contact lens can be effective in the immediate management of large corneal perforations whilst awaiting urgent definitive treatment.

Concepts: Keratitis, Orthokeratology, Corneal ulcer, Lens, Eye, Cornea, Contact lens

14

Keratitis, inflammation of the cornea, can result in partial or total loss of vision and can result from infectious agents (e.g., microbes including bacteria, fungi, amebae, and viruses) or from noninfectious causes (e.g., eye trauma, chemical exposure, and ultraviolet exposure). Contact lens wear is the major risk factor for microbial keratitis; outbreaks of Fusarium and Acanthamoeba keratitis have been associated with contact lens multipurpose solution use, and poor contact lens hygiene is a major risk factor for a spectrum of eye complications, including microbial keratitis and other contact lens-related inflammation. However, the overall burden and the epidemiology of keratitis in the United States have not been well described. To estimate the incidence and cost of keratitis, national ambulatory-care and emergency department databases were analyzed. The results of this analysis showed that an estimated 930,000 doctor’s office and outpatient clinic visits and 58,000 emergency department visits for keratitis or contact lens disorders occur annually; 76.5% of keratitis visits result in antimicrobial prescriptions. Episodes of keratitis and contact lens disorders cost an estimated $175 million in direct health care expenditures, including $58 million for Medicare patients and $12 million for Medicaid patients each year. Office and outpatient clinic visits occupied over 250,000 hours of clinician time annually. Developing effective prevention messages that are disseminated to contact lens users and investigation of additional preventive efforts are important measures to reduce the national incidence of microbial keratitis.

Concepts: Epidemiology, Clinic, Infection, Bacteria, Keratitis, Hospital, Cornea, Contact lens

9

Fusarium keratitis is a destructive eye infection that is difficult to treat and which results in poor outcome. In the tropical and subtropical areas the infection is relatively common and associated with trauma or chronic eye diseases. However, in recent years, an increased incidence has been reported in temperate climate regions. At the German National Reference Center, we observed a steady increase in case numbers since 2014. Here, we present the first German case series of eye infections with Fusarium spp. We identified Fusarium isolates from the eye or eye-related material from 22 patients in 2014 and 2015. Thirteen isolates belonged to the Fusarium solani species complex (FSSC), 6 belonged to the Fusarium oxysporum species complex (FOSC) and three to the Fusarium fujikori species complex (FFSC). FSSC was isolated in 13 of 15 (85 %) definite infections and FOSC in 3 of 4 (75 %) definite contaminations. Furthermore, diagnosis from contact lens swabs or culture of contact lens solution turned out to be highly unreliable. FSSC isolates differed from FOSC and FFSC by distinctly higher minimal inhibitory concentration (MIC) for terbinafine. Outcome was often adverse with 10 patients requiring keratoplasty or enucleation. The use of natamycin as the most effective agent in keratitis caused by filamentous fungi was rare in Germany, possibly due to restricted availability. Keratitis caused by Fusarium spp. (usually FSSC) appears to be a relevant clinical problem in Germany with the use of contact lenses as the predominant risk factor and an adverse outcome.

Concepts: Ophthalmology, Species, Climate, Keratitis, Eye, Cornea, Fusarium, Contact lens

5

Free-living amoebae of the genus Acanthamoeba are causal agents of a severe sight-threatening infection of the cornea known as Acanthamoeba keratitis. Moreover, the number of reported cases worldwide is increasing year after year, mostly in contact lens wearers, although cases have also been reported in non-contact lens wearers. Interestingly, Acanthamoeba keratitis has remained significant, despite our advances in antimicrobial chemotherapy and supportive care. In part, this is due to an incomplete understanding of the pathogenesis and pathophysiology of the disease, diagnostic delays and problems associated with chemotherapeutic interventions. In view of the devastating nature of this disease, here we present our current understanding of Acanthamoeba keratitis and molecular mechanisms associated with the disease, as well as virulence traits of Acanthamoeba that may be potential targets for improved diagnosis, therapeutic interventions and/or for the development of preventative measures. Novel molecular approaches such as proteomics, RNAi and a consensus in the diagnostic approaches for a suspected case of Acanthamoeba keratitis are proposed and reviewed based on data which have been compiled after years of working on this amoebic organism using many different techniques and listening to many experts in this field at conferences, workshops and international meetings. Altogether, this review may serve as the milestone for developing an effective solution for the prevention, control and treatment of Acanthamoeba infections.

Concepts: Amoeboid, Infection, Immune system, Keratitis, Infectious disease, Contact lens, Cornea, Acanthamoeba

4

Acanthamoeba keratitis (AK) is a painful and potentially blinding corneal infection caused by Acanthamoeba spp. In Madrid, environmental studies have demonstrated a high presence of these free-living amoebae in tap water. Since most of AK cases occur in contact lenses (CL) wearers with inadequate hygiene habits, the presence of Acanthamoeba in discarded CL has been studied and compared with other common etiological agents of keratitis, such as Pseudomonas aeruginosa and Staphylococcus aureus.

Concepts: Antibiotic resistance, Pseudomonas aeruginosa, Bacteria, Cornea, Staphylococcus aureus, Contact lens, Keratitis, Acanthamoeba

1

To analyze the characteristics and long-term outcomes of patients that underwent pediatric penetrating keratoplasty (PPK) for herpes simplex virus (HSV) keratitis.

Concepts: Corneal transplantation, Ophthalmology, Encephalitis, Keratitis, Herpesviridae, Virus, Herpes simplex virus, Herpes simplex

1

To investigate the ability of protamine, alone or in combination with other antimicrobial agents, to kill bacteria and fungi associated with contact lens-related keratitis.

Concepts: Microbiology, Corneal ulcer, Bausch & Lomb, Cornea, Keratitis, Bacteria, Contact lens